INFINITI QX56 2008 Factory Service Manual

EC-2
DTC Confirmation Procedure .................................90
Diagnosis Procedure ..............................................91
Component Inspection ............................................95
P0031, P0032, P0051, P0052 A/F SENSOR 1
HEATER .............................................................
97
Description ........................................................... ...97
On Board Diagnosis Logic ......................................97
DTC Confirmation Procedure .................................97
Diagnosis Procedure ..............................................97
Component Inspection ............................................99
P0037, P0038, P0057, P0058 HO2S2 HEAT-
ER ....................................................................
100
Description ........................................................... ..100
On Board Diagnosis Logic .....................................100
DTC Confirmation Procedure ................................100
Diagnosis Procedure .............................................101
Component Inspection ...........................................102
P0075, P0081 IVT CONTROL SOLENOID
VALVE .............................................................
103
Component Description ....................................... ..103
On Board Diagnosis Logic .....................................103
DTC Confirmation Procedure ................................103
Diagnosis Procedure .............................................103
Component Inspection ...........................................104
P0101 MAF SENSOR ......................................106
Component Description ....................................... ..106
On Board Diagnosis Logic .....................................106
DTC Confirmation Procedure ................................106
Overall Function Check .........................................108
Diagnosis Procedure .............................................109
Component Inspection ...........................................111
P0102, P0103 MAF SENSOR ..........................113
Component Description ....................................... ..113
On Board Diagnosis Logic .....................................113
DTC Confirmation Procedure ................................113
Diagnosis Procedure .............................................114
Component Inspection ...........................................115
P0112, P0113 IAT SENSOR ............................118
Component Description ....................................... ..118
On Board Diagnosis Logic .....................................118
DTC Confirmation Procedure ................................118
Diagnosis Procedure .............................................118
Component Inspection ...........................................120
P0116 ECT SENSOR .......................................121
Component Description ....................................... ..121
On Board Diagnosis Logic .....................................121
DTC Confirmation Procedure ................................121
Diagnosis Procedure .............................................122
Component Inspection ...........................................122
P0117, P0118 ECT SENSOR ..........................124
Component Description ....................................... ..124
On Board Diagnosis Logic .....................................124
DTC Confirmation Procedure ............................... .125
Diagnosis Procedure .............................................125
Component Inspection ..........................................126
P0122, P0123 TP SENSOR ..............................128
Component Description ........................................128
On Board Diagnosis Logic ....................................128
DTC Confirmation Procedure ................................128
Diagnosis Procedure .............................................128
Component Inspection ..........................................131
P0125 ECT SENSOR .......................................132
Component Description ........................................132
On Board Diagnosis Logic ....................................132
DTC Confirmation Procedure ................................132
Diagnosis Procedure .............................................133
Component Inspection ..........................................133
P0127 IAT SENSOR .........................................135
Component Description ........................................135
On Board Diagnosis Logic ....................................135
DTC Confirmation Procedure ................................135
Diagnosis Procedure .............................................136
Component Inspection ..........................................136
P0128 THERMOSTAT FUNCTION ..................138
On Board Diagnosis Logic ................................... .138
DTC Confirmation Procedure ................................138
Diagnosis Procedure .............................................140
Component Inspection ..........................................140
P0130, P0150 A/F SENSOR 1 .........................141
Component Description ....................................... .141
On Board Diagnosis Logic ....................................141
DTC Confirmation Procedure ................................141
Overall Function Check .........................................142
Diagnosis Procedure .............................................142
P0131, P0151 A/F SENSOR 1 .........................145
Component Description ....................................... .145
On Board Diagnosis Logic ....................................145
DTC Confirmation Procedure ................................145
Diagnosis Procedure .............................................146
P0132, P0152 A/F SENSOR 1 .........................149
Component Description ....................................... .149
On Board Diagnosis Logic ....................................149
DTC Confirmation Procedure ................................149
Diagnosis Procedure .............................................150
P0133, P0153 A/F SENSOR 1 .........................153
Component Description ....................................... .153
On Board Diagnosis Logic ....................................153
DTC Confirmation Procedure ................................153
Diagnosis Procedure .............................................154
P0137, P0157 HO2S2 .......................................159
Component Description ....................................... .159
On Board Diagnosis Logic ....................................159
DTC Confirmation Procedure ................................159
Overall Function Check .........................................160
Revision: March 2010 2008 QX56

EC-3
C
DE
F
G H
I
J
K L
M
EC A
N
O P
Diagnosis Procedure ...........................................
..
160
Component Inspection ..........................................162
P0138, P0158 HO2S2 ......................................164
Component Description ....................................... ..164
On Board Diagnosis Logic ....................................164
DTC Confirmation Procedure ................................164
Overall Function Check .........................................165
Diagnosis Procedure .............................................166
Component Inspection ..........................................169
P0139, P0159 HO2S2 ......................................171
Component Description ....................................... ..171
On Board Diagnosis Logic ....................................171
DTC Confirmation Procedure ................................171
Overall Function Check .........................................172
Diagnosis Procedure .............................................172
Component Inspection ..........................................174
P0171, P0174 FUEL INJECTION SYSTEM
FUNCTION .......................................................
176
On Board Diagnosis Logic .................................. ..176
DTC Confirmation Procedure ................................176
Diagnosis Procedure .............................................179
P0172, P0175 FUEL INJECTION SYSTEM
FUNCTION .......................................................
182
On Board Diagnosis Logic .................................. ..182
DTC Confirmation Procedure ................................182
Diagnosis Procedure .............................................185
P0181 FTT SENSOR ........................................188
Component Description ....................................... ..188
On Board Diagnosis Logic ....................................188
DTC Confirmation Procedure ................................188
Diagnosis Procedure .............................................189
Component Inspection ..........................................190
P0182, P0183 FTT SENSOR ...........................191
Component Description ....................................... ..191
On Board Diagnosis Logic ....................................191
DTC Confirmation Procedure ................................191
Diagnosis Procedure .............................................191
Component Inspection ..........................................193
P0222, P0223 APP SENSOR ...........................194
Component Description .........................................194
On Board Diagnosis Logic ....................................194
DTC Confirmation Procedure ................................194
Diagnosis Procedure .............................................194
Component Inspection ..........................................197
P0300, P0301, P0302, P0303, P0304, P0305,
P0306, P0307, P0308 MISFIRE .......................
198
On Board Diagnosis Logic .................................. ..198
DTC Confirmation Procedure ................................198
Diagnosis Procedure .............................................199
P0327, P0328, P0332, P0333 KS ....................204
Component Description ....................................... ..204
On Board Diagnosis Logic ....................................204
DTC Confirmation Procedure .............................. ..204
Diagnosis Procedure .............................................204
Component Inspection ...........................................206
P0335 CKP SENSOR (POS) ...........................207
Component Description .........................................207
On Board Diagnosis Logic .....................................207
DTC Confirmation Procedure ................................207
Diagnosis Procedure .............................................208
Component Inspection ...........................................209
P0340 CMP SENSOR (PHASE) .....................211
Component Description .........................................211
On Board Diagnosis Logic .....................................211
DTC Confirmation Procedure ................................211
Diagnosis Procedure .............................................212
Component Inspection ...........................................213
P0420, P0430 THREE WAY CATALYST
FUNCTION ......................................................
215
On Board Diagnosis Logic ................................... ..215
DTC Confirmation Procedure ................................215
Overall Function Check .........................................216
Diagnosis Procedure .............................................216
P0441 EVAP CONTROL SYSTEM .................219
System Description ................................................219
On Board Diagnosis Logic .....................................219
DTC Confirmation Procedure ................................219
Overall Function Check .........................................220
Diagnosis Procedure .............................................220
P0442 EVAP CONTROL SYSTEM .................224
On Board Diagnosis Logic .....................................224
DTC Confirmation Procedure ................................224
Diagnosis Procedure .............................................225
Component Inspection ...........................................230
P0443 EVAP CANISTER PURGE VOLUME
CONTROL SOLENOID VALVE ......................
231
Description .............................................................231
On Board Diagnosis Logic .....................................231
DTC Confirmation Procedure ................................231
Diagnosis Procedure .............................................232
Component Inspection ...........................................234
P0444, P0445 EVAP CANISTER PURGE
VOLUME CONTROL SOLENOID VALVE ......
236
Description .............................................................236
On Board Diagnosis Logic .....................................236
DTC Confirmation Procedure ................................237
Diagnosis Procedure .............................................237
Component Inspection ...........................................238
P0447 EVAP CANISTER VENT CONTROL
VALVE .............................................................
239
Component Description .........................................239
On Board Diagnosis Logic .....................................239
DTC Confirmation Procedure ................................239
Diagnosis Procedure .............................................239
Revision: March 2010 2008 QX56

EC-4
Component Inspection ...........................................241
P0448 EVAP CANISTER VENT CONTROL
VALVE .............................................................
243
Component Description ....................................... ..243
On Board Diagnosis Logic .....................................243
DTC Confirmation Procedure ................................243
Diagnosis Procedure .............................................244
Component Inspection ...........................................245
P0451 EVAP CONTROL SYSTEM PRES-
SURE SENSOR ...............................................
247
Component Description ....................................... ..247
On Board Diagnosis Logic .....................................247
DTC Confirmation Procedure ................................247
Diagnosis Procedure .............................................247
Component Inspection ...........................................248
P0452 EVAP CONTROL SYSTEM PRES-
SURE SENSOR ...............................................
250
Component Description ....................................... ..250
On Board Diagnosis Logic .....................................250
DTC Confirmation Procedure ................................250
Diagnosis Procedure .............................................251
Component Inspection ...........................................253
P0453 EVAP CONTROL SYSTEM PRES-
SURE SENSOR ...............................................
254
Component Description ....................................... ..254
On Board Diagnosis Logic .....................................254
DTC Confirmation Procedure ................................254
Diagnosis Procedure .............................................255
Component Inspection ...........................................258
P0455 EVAP CONTROL SYSTEM ..................259
On Board Diagnosis Logic ................................... ..259
DTC Confirmation Procedure ................................259
Diagnosis Procedure .............................................260
Component Inspection ...........................................264
P0456 EVAP CONTROL SYSTEM ..................266
On Board Diagnosis Logic ................................... ..266
DTC Confirmation Procedure ................................267
Overall Function Check .........................................267
Diagnosis Procedure .............................................268
Component Inspection ...........................................272
P0460 FUEL LEVEL SENSOR ........................274
Component Description ....................................... ..274
On Board Diagnosis Logic .....................................274
DTC Confirmation Procedure ................................274
Diagnosis Procedure .............................................274
P0461 FUEL LEVEL SENSOR ........................276
Component Description ....................................... ..276
On Board Diagnosis Logic .....................................276
Overall Function Check .........................................276
Diagnosis Procedure .............................................277
P0462, P0463 FUEL LEVEL SENSOR ...........278
Component Description ....................................... ..278
On Board Diagnosis Logic ................................... .278
DTC Confirmation Procedure ................................278
Diagnosis Procedure .............................................278
P0500 VSS ........................................................280
Description ........................................................... .280
On Board Diagnosis Logic ....................................280
DTC Confirmation Procedure ................................280
Overall Function Check .........................................281
Diagnosis Procedure .............................................281
P0506 ISC SYSTEM .........................................282
Description ........................................................... .282
On Board Diagnosis Logic ....................................282
DTC Confirmation Procedure ................................282
Diagnosis Procedure .............................................282
P0507 ISC SYSTEM .........................................284
Description ........................................................... .284
On Board Diagnosis Logic ....................................284
DTC Confirmation Procedure ................................284
Diagnosis Procedure .............................................284
P0550 PSP SENSOR .......................................286
Component Description ....................................... .286
On Board Diagnosis Logic ....................................286
DTC Confirmation Procedure ................................286
Diagnosis Procedure .............................................286
Component Inspection ..........................................288
P0603 ECM POWER SUPPLY .........................289
Description ........................................................... .289
DTC Logic .............................................................289
Diagnosis Procedure .............................................289
P0605 ECM .......................................................291
Component Description ....................................... .291
On Board Diagnosis Logic ....................................291
DTC Confirmation Procedure ................................291
Diagnosis Procedure .............................................292
P0643 SENSOR POWER SUPPLY ..................293
On Board Diagnosis Logic ....................................293
DTC Confirmation Procedure ................................293
Diagnosis Procedure .............................................293
P0850 PNP SWITCH ........................................296
Component Description ........................................296
On Board Diagnosis Logic ....................................296
DTC Confirmation Procedure ................................296
Overall Function Check .........................................296
Diagnosis Procedure .............................................297
P1140, P1145 IVT CONTROL POSITION
SENSOR ...........................................................
299
Component Description ....................................... .299
On Board Diagnosis Logic ....................................299
DTC Confirmation Procedure ................................299
Diagnosis Procedure .............................................299
Component Inspection ..........................................302
Revision: March 2010 2008 QX56

EC-5
C
DE
F
G H
I
J
K L
M
EC A
N
O P
P1148, P1168 CLOSED LOOP CONTROL ... ..303
On Board Diagnosis Logic .................................. ..303
P1211 TCS CONTROL UNIT ...........................304
Description .......................................................... ..304
On Board Diagnosis Logic ....................................304
DTC Confirmation Procedure ................................304
Diagnosis Procedure .............................................304
P1212 TCS COMMUNICATION LINE ..............305
Description .......................................................... ..305
On Board Diagnosis Logic ....................................305
DTC Confirmation Procedure ................................305
Diagnosis Procedure .............................................305
P1217 ENGINE OVER TEMPERATURE .........306
On Board Diagnosis Logic .................................. ..306
Overall Function Check .........................................306
Diagnosis Procedure .............................................307
Main 13 Causes of Overheating ............................308
P1225 TP SENSOR ..........................................310
Component Description ....................................... ..310
On Board Diagnosis Logic ....................................310
DTC Confirmation Procedure ................................310
Diagnosis Procedure .............................................310
P1226 TP SENSOR ..........................................312
Component Description ....................................... ..312
On Board Diagnosis Logic ....................................312
DTC Confirmation Procedure ................................312
Diagnosis Procedure .............................................312
P1421 COLD START CONTROL .....................314
Description .......................................................... ..314
On Board Diagnosis Logic ....................................314
DTC Confirmation Procedure ................................314
Diagnosis Procedure .............................................314
P1550 BATTERY CURRENT SENSOR ...........316
Component Description ....................................... ..316
On Board Diagnosis Logic ....................................316
DTC Confirmation Procedure ................................316
Diagnosis Procedure .............................................316
Component Inspection ..........................................318
P1551, P1552 BATTERY CURRENT SEN-
SOR ..................................................................
320
Component Description ....................................... ..320
On Board Diagnosis Logic ....................................320
DTC Confirmation Procedure ................................320
Diagnosis Procedure .............................................320
Component Inspection ..........................................322
P1553 BATTERY CURRENT SENSOR ...........324
Component Description ....................................... ..324
On Board Diagnosis Logic ....................................324
DTC Confirmation Procedure ................................324
Diagnosis Procedure .............................................324
Component Inspection ..........................................326
P1554 BATTERY CURRENT SENSOR ..........328
Component Description ....................................... ..328
On Board Diagnosis Logic .....................................328
Overall Function Check .........................................328
Diagnosis Procedure .............................................329
Component Inspection ...........................................330
P1564 ICC STEERING SWITCH .....................332
Component Description .........................................332
On Board Diagnosis Logic .....................................332
DTC Confirmation Procedure ................................332
Diagnosis Procedure .............................................332
Component Inspection ...........................................335
P1564 ASCD STEERING SWITCH .................336
Component Description .........................................336
On Board Diagnosis Logic .....................................336
DTC Confirmation Procedure ................................336
Diagnosis Procedure .............................................336
Component Inspection ...........................................338
P1568 ICC FUNCTION ....................................340
On Board Diagnosis Logic .....................................340
DTC Confirmation Procedure ................................340
Diagnosis Procedure .............................................340
P1572 ICC BRAKE SWITCH ..........................341
Component Description .........................................341
On Board Diagnosis Logic .....................................341
DTC Confirmation Procedure ................................341
Diagnosis Procedure .............................................342
Component Inspection ...........................................346
P1572 ASCD BRAKE SWITCH ......................347
Component Description .........................................347
On Board Diagnosis Logic .....................................347
DTC Confirmation Procedure ................................347
Diagnosis Procedure .............................................348
Component Inspection ...........................................351
P1574 ICC VEHICLE SPEED SENSOR .........352
Component Description .........................................352
On Board Diagnosis Logic .....................................352
DTC Confirmation Procedure ................................352
Diagnosis Procedure .............................................352
P1574 ASCD VEHICLE SPEED SENSOR .....354
Component Description .........................................354
On Board Diagnosis Logic .....................................354
DTC Confirmation Procedure ................................354
Diagnosis Procedure .............................................354
P1805 BRAKE SWITCH .................................356
Description .............................................................356
On Board Diagnosis Logic .....................................356
DTC Confirmation Procedure ................................356
Diagnosis Procedure .............................................356
Component Inspection ...........................................358
P2100, P2103 THROTTLE CONTROL MO-
TOR RELAY ....................................................
359
Revision: March 2010 2008 QX56

EC-6
Component Description .........................................359
On Board Diagnosis Logic .....................................359
DTC Confirmation Procedure ................................359
Diagnosis Procedure .............................................360
P2101 ELECTRIC THROTTLE CONTROL
FUNCTION .......................................................
362
Description ........................................................... ..362
On Board Diagnosis Logic .....................................362
DTC Confirmation Procedure ................................362
Diagnosis Procedure .............................................362
Component Inspection ...........................................365
P2118 THROTTLE CONTROL MOTOR ..........366
Component Description ....................................... ..366
On Board Diagnosis Logic .....................................366
DTC Confirmation Procedure ................................366
Diagnosis Procedure .............................................366
Component Inspection ...........................................367
P2119 ELECTRIC THROTTLE CONTROL
ACTUATOR .....................................................
368
Component Description ....................................... ..368
On Board Diagnosis Logic .....................................368
DTC Confirmation Procedure ................................368
Diagnosis Procedure .............................................369
P2122, P2123 APP SENSOR ..........................370
Component Description ....................................... ..370
On Board Diagnosis Logic .....................................370
DTC Confirmation Procedure ................................370
Diagnosis Procedure .............................................371
Component Inspection ...........................................372
P2127, P2128 APP SENSOR ..........................373
Component Description ....................................... ..373
On Board Diagnosis Logic .....................................373
DTC Confirmation Procedure ................................373
Diagnosis Procedure .............................................373
Component Inspection ...........................................376
P2135 TP SENSOR .........................................377
Component Description ....................................... ..377
On Board Diagnosis Logic .....................................377
DTC Confirmation Procedure ................................377
Diagnosis Procedure .............................................377
Component Inspection ...........................................380
P2138 APP SENSOR ......................................381
Component Description ....................................... ..381
On Board Diagnosis Logic .....................................381
DTC Confirmation Procedure ................................381
Diagnosis Procedure .............................................382
Component Inspection ...........................................384
P2A00, P2A03 A/F SENSOR 1 .......................385
Component Description ....................................... ..385
On Board Diagnosis Logic .....................................385
DTC Confirmation Procedure ................................385
Diagnosis Procedure .............................................386
ASCD BRAKE SWITCH ...................................390
Component Description ....................................... .390
Diagnosis Procedure .............................................390
Component Inspection ..........................................393
ASCD INDICATOR ...........................................394
Component Description ....................................... .394
Diagnosis Procedure .............................................394
COOLING FAN .................................................395
Diagnosis Procedure ............................................ .395
Component Inspection ..........................................395
ELECTRICAL LOAD SIGNAL ..........................397
Description ........................................................... .397
Diagnosis Procedure .............................................397
FUEL INJECTOR ..............................................399
Component Description ....................................... .399
Diagnosis Procedure .............................................399
Component Inspection ..........................................401
FUEL PUMP .....................................................402
Description ........................................................... .402
Diagnosis Procedure .............................................402
Component Inspection ..........................................405
ICC BRAKE SWITCH ..................................... ..406
Component Description ....................................... .406
Diagnosis Procedure .............................................406
Component Inspection ..........................................409
IGNITION SIGNAL ............................................411
Component Description ....................................... .411
Diagnosis Procedure .............................................411
Component Inspection ..........................................414
ON BOARD REFUELING VAPOR RECOV-
ERY (ORVR) .....................................................
416
System Description .............................................. .416
Diagnosis Procedure .............................................416
Component Inspection ..........................................418
POSITIVE CRANKCASE VENTILATION .........421
Description ........................................................... .421
Component Inspection ..........................................421
REFRIGERANT PRESSURE SENSOR ...........423
Component Description ....................................... .423
Diagnosis Procedure .............................................423
ECU DIAGNOSIS ......................................426
ECM ................................................................ ..426
CONSULT-lll Reference Value in Data Monitor
Mode .................................................................... .
426
ECM Harness Connector Terminal Layout ...........429
ECM Terminal and Reference Value ....................429
Wiring Diagram - ENGINE CONTROL SYSTEM - .439
Fail-Safe Chart ......................................................459
DTC Inspection Priority Chart ...............................461
Revision: March 2010 2008 QX56

EC-7
C
DE
F
G H
I
J
K L
M
EC A
N
O P
DTC Index ...........................................................
..
462
Emission-related Diagnostic Information ...............466
SYMPTOM DIAGNOSIS ..... .......................481
ENGINE CONTROL SYSTEM SYMPTOMS .. ..481
Symptom Matrix Chart ........................................ ..481
NORMAL OPERATING CONDITION ...............485
Fuel Cut Control (at No Load and High Engine
Speed) ................................................................. ..
485
PRECAUTION ............................................486
PRECAUTIONS .............................................. ..486
Precaution for Supplemental Restraint System
(SRS) "AIR BAG" and "SEAT BELT PRE-TEN-
SIONER" ............................................................. ..
486
Precaution Necessary for Steering Wheel Rota-
tion After Battery Disconnect ............................... ..
486
On Board Diagnosis (OBD) System of Engine and
A/T .........................................................................
487
Precaution .............................................................487
PREPARATION .........................................491
PREPARATION .............................................. ..491
Special Service Tool ........................................... ..491
Commercial Service Tool ......................................492
ON-VEHICLE MAINTENANCE ..................494
FUEL PRESSURE .......................................... ..494
Fuel Pressure Check .............................................494
EVAP LEAK CHECK ......................................496
How to Detect Fuel Vapor Leakage ..................... ..496
ON-VEHICLE REPAIR ...............................498
EVAP CANISTER ............................................498
Component Inspection ......................................... ..498
Removal and Installation .......................................498
INTAKE VALVE TIMING CONTROL ..............500
Intake Valve Timing Control Solenoid Valve (LH) ..500
Intake Valve Timing Cont rol Solenoid Valve (RH) ..500
Intake Valve Timing Control Position Sensor (LH) ..501
Intake Valve Timing Control Position Sensor (RH) ..501
Camshaft Position Sensor (PHASE) .....................501
SERVICE DATA AND SPECIFICATIONS
(SDS) ............... .......................................... .
503
SERVICE DATA AND SPECIFICATIONS
(SDS) ...............................................................
503
Fuel Pressure ...................................................... ..503
Idle Speed and Ignition Timing ..............................503
Calculated Load Value ..........................................503
Mass Air Flow Sensor ............................................503
Intake Air Temperature Sensor .............................503
Engine Coolant Temperature Sensor ....................503
A/F Sensor 1 Heater ..............................................503
Heated Oxygen sensor 2 Heater ...........................504
Crankshaft Position Sensor (POS) ........................504
Camshaft Position Sensor (PHASE) .....................504
Throttle Control Motor ............................................504
Fuel Injector ...........................................................504
Fuel Pump .............................................................504
Revision: March 2010 2008 QX56

EC-8
< BASIC INSPECTION >[VK56DE]
DIAGNOSIS AND REPAIR WORKFLOW
BASIC INSPECTION
DIAGNOSIS AND REPAIR WORKFLOW
Trouble Diagnosis IntroductionINFOID:0000000001351337
INTRODUCTION
The engine has an ECM to control major systems such as fuel con-
trol, ignition control, idle air control system, etc. The ECM accepts
input signals from sensors and instantly drives actuators. It is essen-
tial that both input and output signals are proper and stable. At the
same time, it is important that there are no malfunctions such as vac-
uum leaks, fouled spark plugs, or
other malfunctions with the engine.
It is much more difficult to diagnose an incident that occurs intermit-
tently rather than continuously. Most intermittent incidents are
caused by poor electric connections or improper wiring. In this case,
careful checking of suspected circuits may help prevent the replace-
ment of good parts.
A visual check only may not find the cause of the incidents. A road
test with CONSULT-III (or GST) or a circuit tester connected should
be performed. Follow the Work Flow on "WORK FLOW" .
Before undertaking actual checks, take a few minutes to talk with a
customer who approaches with a driveability complaint. The cus-
tomer can supply good information about such incidents, especially
intermittent ones. Find out what symptoms are present and under
what conditions they occur. A Di agnostic Worksheet like the example
on "Worksheet Sample" should be used.
Start your diagnosis by looking fo r conventional malfunctions first.
This will help troubleshoot driveability malfunctions on an electroni-
cally controlled engine vehicle.
WORK FLOW
MEF036D
SEF233G
SEF234G
Revision: March 2010 2008 QX56

DIAGNOSIS AND REPAIR WORKFLOWEC-9
< BASIC INSPECTION > [VK56DE]
C
D
E
F
G H
I
J
K L
M A
EC
NP
O
Overall Sequence
Detailed Flow
1.GET INFORMATION FOR SYMPTOM
Get the detailed information from the customer about the symptom (the condition and the environment when
the incident/malfunction occurred) using the "Worksheet Sample" .
>> GO TO 2.
PBIB3456E
Revision: March 2010 2008 QX56

EC-10
< BASIC INSPECTION >[VK56DE]
DIAGNOSIS AND REPAIR WORKFLOW
2.CHECK DTC*1
1. Check DTC*1 .
2. Perform the following procedure if DTC*
1 is displayed.
- Record DTC*
1 and freeze frame data*2 . (Print them out with CONSULT-III or GST.)
- Erase DTC*
1 . (Refer to EC-462, "DTC Index" .)
- Study the relationship between the cause detected by DTC*
1 and the symptom described by the cus-
tomer. (Symptom Matrix Chart is useful. Refer to EC-481, "
Symptom Matrix Chart" .)
3. Check related service bulletins for information.
Is any symptom described and any DTC detected?
Symptom is described, DTC*1 is displayed>>GO TO 3.
Symptom is described, DTC*
1 is not displayed>>GO TO 4.
Symptom is not described, DTC*
1 is displayed>>GO TO 5.
3.CONFIRM THE SYMPTOM
Try to confirm the symptom described by the customer (except MIL ON).
DIAGNOSIS WORK SHEET is useful to verify the incident.
Connect CONSULT-III to the vehicle and check real time diagnosis results.
Verify relation between the symptom and the condition when the symptom is detected.
>> GO TO 5.
4.CONFIRM THE SYMPTOM
Try to confirm the symptom described by the customer.
DIAGNOSIS WORK SHEET is useful to verify the incident.
Connect CONSULT-III to the vehicle and check real time diagnosis results.
Verify relation between the symptom and the condition when the symptom is detected.
>> GO TO 6.
5.PERFORM DTC CONFIRMATION PROCEDURE
Perform DTC Confirmation Procedure for the displayed DTC* , and then make sure that DTC*
1 is detected
again.
If two or more DTCs*
1 are detected, refer to EC-461, "DTC Inspection Priority Chart" and determine trouble
diagnosis order.
NOTE:
• Freeze frame data*
2 is useful if the DTC*1 is not detected.
• Perform Overall Function Check if DTC Confirma tion Procedure is not included on Service Manual. This
simplified check procedure is an effective alternative though DTC*
1 cannot be detected during this check.
If the result of Overall Function Check is NG, it is the same as the detection of DTC*
1 by DTC Confirmation
Procedure.
Is DTC*
1 detected?
Yes >> GO TO 10.
No >> Check according to GI-38, "
Intermittent Incident" .
6.PERFORM BASIC INSPECTION
Perform EC-13, "
Basic Inspection" .
With CONSULT-III>>GO TO 7.
Without CONSULT-III>>GO TO 9.
7.PERFORM SPEC IN DATA MONITOR MODE
With CONSULT-III
Make sure that “MAS A/F SE-B1”, “B/FUEL SCHDL”, and “A/F ALPHA-B1”, “A/F ALPHA-B2” are within the SP
value using CONSULT-III “SPEC” in “DATA MONITOR” mode. Refer to EC-75
.
Revision: March 2010 2008 QX56

DIAGNOSIS AND REPAIR WORKFLOWEC-11
< BASIC INSPECTION > [VK56DE]
C
D
E
F
G H
I
J
K L
M A
EC
NP
O
Are they within the SP value?
Yes >> GO TO 9.
No >> GO TO 8.
8.DETECT MALFUNCTIONING PART BY TROUBLE DIAGNOSIS - SPECIFICATION VALUE
Detect malfunctioning part according to EC-76, "
Diagnosis Procedure".
Is malfunctioning part detected?
Yes >> GO TO 11.
No >> GO TO 9.
9.DETECT MALFUNCTIONING SYST EM BY SYMPTOM MATRIX CHART
Detect malfunctioning system according to EC-481, "
Symptom Matrix Chart" based on the confirmed symp-
tom in step 4, and determine the trouble diagnosis order based on possible causes and symptom.
>> GO TO 10.
10.DETECT MALFUNCTIONING PART BY DIAGNOSTIC PROCEDURE
Inspect according to Diagnostic Procedure of the system.
NOTE:
The Diagnostic Procedure in EC section described based on open circuit inspection. A short circuit inspection
is also required for the circuit check in the Diagnostic Procedure. For details, refer to Circuit Inspection in GI-
34, "Work Flow".
Is malfunctioning part detected?
Yes >> GO TO 11.
No >> Monitor input data from related sensors or check voltage of related ECM terminals using CON- SULT-III. Refer to EC-429, "
ECM Terminal and Reference Value", EC-426, "CONSULT-lll Refer-
ence Value in Data Monitor Mode".
11 .REPAIR OR REPLACE THE MALFUNCTIONING PART
1. Repair or replace the malfunctioning part.
2. Reconnect parts or connectors disconnected during Diagnostic Procedure again after repair and replace-
ment.
3. Check DTC. If DTC is displayed, erase it, refer to EC-462, "
DTC Index".
>> GO TO 12.
12.FINAL CHECK
When DTC was detected in step 2, perform DTC Confirmation Procedure or Overall Function Check again,
and then make sure that the malfunction have been repaired securely.
When symptom was described from the customer, refer to confirmed symptom in step 3 or 4, and make sure
that the symptom is not detected.
OK or NG
NG (DTC*1 is detected)>>GO TO 10.
NG (Symptom remains)>>GO TO 6.
OK >> 1. Before returning the vehicle to the cu stomer, make sure to erase unnecessary DTC*
1 in ECM
and TCM (Transmission Control Module). (Refer to EC-462, "
DTC Index" and TM-30, "OBD-
II Diagnostic Trouble Code (DTC)".)
2. If the completion of SRT is needed, drive vehicle under the specific driving pattern. Refer to EC-462, "
DTC Index".
3. INSPECTION END
*1: Include 1st trip DTC.
*2: Include 1st trip freeze frame data.
DIAGNOSTIC WORKSHEET
Description
Revision: March 2010 2008 QX56