maf INFINITI QX56 2006 Factory Service Manual

EC-2Revision: November 20092006 QX56
Description ...........................................................
.144
Diagnostic Procedure .......................................... .144
POWER SUPPLY AND GROUND CIRCUIT .......... .145
Wiring Diagram .................................................... .145
Diagnostic Procedure .......................................... .146
Ground Inspection ............................................... .150
DTC U1000, U1001 CAN COMMUNICATION LINE .151
Description ........................................................... .151
On Board Diagnosis Logic ................................... .151
DTC Confirmation Procedure .............................. .151
Wiring Diagram .................................................... .152
Diagnostic Procedure .......................................... .153
DTC U1010 CAN COMMUNICATION .................... .154
Description ........................................................... .154
On Board Diagnosis Logic ................................... .154
DTC Confirmation Procedure .............................. .154
Diagnostic Procedure .......................................... .155
DTC P0031, P0032, P0051, P0052 A/F SENSOR 1
HEATER ................................................................. .156
Description ........................................................... .156
CONSULT-II Reference Value in Data Monitor Mode .156
On Board Diagnosis Logic ................................... .156
DTC Confirmation Procedure .............................. .156
Wiring Diagram .................................................... .157
Diagnostic Procedure .......................................... .160
Component Inspection ......................................... .162
Removal and Installation ..................................... .162
DTC P0037, P0038, P0057, P0058 HO2S2 HEATER .163
Description ........................................................... .163
CONSULT-II Reference Value in Data Monitor Mode .163
On Board Diagnosis Logic ................................... .163
DTC Confirmation Procedure .............................. .164
Wiring Diagram .................................................... .165
Diagnostic Procedure .......................................... .168
Component Inspection ......................................... .170
Removal and Installation ..................................... .170
DTC P0101 MAF SENSOR .................................... .171
Component Description ....................................... .171
CONSULT-II Reference Value in Data Monitor Mode .171
On Board Diagnosis Logic ................................... .171
DTC Confirmation Procedure .............................. .172
Overall Function Check ....................................... .173
Wiring Diagram .................................................... .174
Diagnostic Procedure .......................................... .175
Component Inspection ......................................... .178
Removal and Installation ..................................... .179
DTC P0102, P0103 MAF SENSOR ........................ .180
Component Description ....................................... .180
CONSULT-II Reference Value in Data Monitor Mode .180
On Board Diagnosis Logic ................................... .180
DTC Confirmation Procedure .............................. .181
Wiring Diagram .................................................... .182
Diagnostic Procedure .......................................... .183
Component Inspection ......................................... .186
Removal and Installation ..................................... .187DTC P0112, P0113 IAT SENSOR ...........................
.188
Component Description ....................................... .188
On Board Diagnosis Logic ................................... .188
DTC Confirmation Procedure ............................... .188
Wiring Diagram .................................................... .189
Diagnostic Procedure ........................................... .190
Component Inspection ......................................... .191
Removal and Installation ...................................... .191
DTC P0117, P0118 ECT SENSOR ......................... .192
Component Description ....................................... .192
On Board Diagnosis Logic ................................... .192
DTC Confirmation Procedure ............................... .193
Wiring Diagram .................................................... .194
Diagnostic Procedure ........................................... .195
Component Inspection ......................................... .196
Removal and Installation ...................................... .197
DTC P0122, P0123 TP SENSOR ........................... .198
Component Description ....................................... .198
CONSULT-II Reference Value in Data Monitor Mode .198
On Board Diagnosis Logic ................................... .198
DTC Confirmation Procedure ............................... .199
Wiring Diagram .................................................... .200
Diagnostic Procedure ........................................... .201
Component Inspection ......................................... .204
Removal and Installation ...................................... .204
DTC P0125 ECT SENSOR ..................................... .205
Component Description ....................................... .205
On Board Diagnosis Logic ................................... .205
DTC Confirmation Procedure ............................... .206
Diagnostic Procedure ........................................... .206
Component Inspection ......................................... .207
Removal and Installation ...................................... .207
DTC P0127 IAT SENSOR ....................................... .208
Component Description ....................................... .208
On Board Diagnosis Logic ................................... .208
DTC Confirmation Procedure ............................... .208
Diagnostic Procedure ........................................... .209
Component Inspection ......................................... .210
Removal and Installation ...................................... .210
DTC P0128 THERMOSTAT FUNCTION ................ .211
On Board Diagnosis Logic ................................... .211
DTC Confirmation Procedure ............................... .211
Diagnostic Procedure ........................................... .211
Component Inspection ......................................... .212
Removal and Installation ...................................... .212
DTC P0130, P0150 A/F SENSOR 1 ....................... .213
Component Description ....................................... .213
CONSULT-II Reference Value in Data Monitor Mode .213
On Board Diagnosis Logic ................................... .213
DTC Confirmation Procedure ............................... .213
Overall Function Check ........................................ .214
Wiring Diagram .................................................... .216
Diagnostic Procedure ........................................... .219
Removal and Installation ...................................... .222
DTC P0131, P0151 A/F SENSOR 1 ....................... .223
Component Description ....................................... .223
CONSULT-II Reference Value in Data Monitor Mode

EC-8Revision: November 2009
INDEX FOR DTC
2006 QX56
INDEX FOR DTCPFP:00024
DTC No. IndexUBS00KYY
NOTE:

If DTC U1000 or U1001 is displayed with other DTC, first perform the trouble diagnosis for DTC
U1000, U1001. Refer to EC-151, "
DTC U1000, U1001 CAN COMMUNICATION LINE" .

If DTC U1010 is displayed with other DTC, first perform the trouble diagnosis for DTC U1010. Refer
to EC-154, "
DTC U1010 CAN COMMUNICATION" .
DTC*1
Items
(CONSULT-II screen terms) Reference page
CONSULT-II
GST*
2ECM*3
U1000 1000*4CAN COMM CIRCUIT EC-151
U1001
1001*4CAN COMM CIRCUIT EC-151
U10101010 CONTROL UNIT(CAN) EC-154
P00000000NO DTC IS DETECTED.
FURTHER TESTING
MAY BE REQUIRED. —
P0031 0031 A/F SEN1 HTR (B1) EC-156
P00320032 A/F SEN1 HTR (B1) EC-156
P00370037 HO2S2 HTR (B1) EC-163
P00380038 HO2S2 HTR (B1) EC-163
P00510051 A/F SEN1 HTR (B2) EC-156
P00520052 A/F SEN1 HTR (B2) EC-156
P00570057 HO2S2 HTR (B2) EC-163
P00580058 HO2S2 HTR (B2) EC-163
P01010101 MAF SEN/CIRCUIT EC-171
P01020102 MAF SEN/CIRCUIT EC-180
P01030103 MAF SEN/CIRCUIT EC-180
P01120112 IAT SEN/CIRCUIT EC-188
P01130113 IAT SEN/CIRCUIT EC-188
P01170117 ECT SEN/CIRC EC-192
P01180118 ECT SEN/CIRC EC-192
P01220122 TP SEN 2/CIRC EC-198
P01230123 TP SEN 2/CIRC EC-198
P01250125 ECT SENSOR EC-205
P01270127 IAT SENSOR EC-208
P01280128 THERMSTAT FNCTN EC-211
P01300130 A/F SENSOR1 (B1) EC-213
P01310131 A/F SEN1 (B1) EC-223
P01320132 A/F SENSOR1 (B1) EC-232
P01330133 A/F SENSOR1 (B1) EC-241
P01370137 HO2S2 (B2) EC-253
P01380138 HO2S2 (B1) EC-264
P01390139 HO2S2 (B1) EC-277
P01500150 A/F SENSOR1 (B2) EC-213
P01510151 A/F SENSOR1 (B2) EC-223
P01520152 A/F SENSOR1 (B2) EC-232

EC-14Revision: November 2009
INDEX FOR DTC
2006 QX56
FUEL SYS-RICH-B2P01750175 EC-299
HLR/C SOL/CIRC P17671767 AT-151
HLR/C SOL FNCTN P17691769 AT-153
HO2S2 (B1) P01370137 EC-253
HO2S2 (B1) P01380138 EC-264
HO2S2 (B1) P01390139 EC-277
HO2S2 (B2) P01570157 EC-253
HO2S2 (B2) P01580158 EC-264
HO2S2 (B2) P01590159 EC-277
HO2S2 HTR (B1) P00370037 EC-163
HO2S2 HTR (B1) P00380038 EC-163
HO2S2 HTR (B2) P00570057 EC-163
HO2S2 HTR (B2) P00580058 EC-163
I/C SOLENOID/CIRC P17521752 AT-139
I/C SOLENOID FNCTN P17541754 AT-141
IAT SEN/CIRCUIT P01120112 EC-188
IAT SEN/CIRCUIT P01130113 EC-188
IAT SENSOR P01270127 EC-208
ISC SYSTEM P05060506 EC-444
ISC SYSTEM P05070507 EC-446
KNOCK SEN/CIRC-B1 P03270327 EC-335
KNOCK SEN/CIRC-B1 P03280328 EC-335
KNOCK SEN/CIRC-B2 P03320332 EC-335
KNOCK SEN/CIRC-B2 P03330333 EC-335
L/PRESS SOL/CIRC P07450745 AT-122
LC/B SOLENOID/CIRC P17721772 AT-155
LC/B SOLENOID FNCT P17741774 AT-157
MAF SEN/CIRCUIT P01010101 EC-171
MAF SEN/CIRCUIT P01020102 EC-180
MAF SEN/CIRCUIT P01030103 EC-180
MULTI CYL MISFIRE P03000300 EC-327
NATS MALFUNCTION P1610 - P16151610 - 1615 BL-137
NO DTC IS DETECTED.
FURTHER TESTING
MAY BE REQUIRED. P0000
0000 —
P-N POS SW/CIRCUIT P08500850 EC-465
PNP SW/CIRC P07050705 AT-105
PURG VOLUME CONT/V P04430443 EC-373
PURG VOLUME CONT/V P04440444 EC-381
PURG VOLUME CONT/V P04450445 EC-381
PW ST P SEN/CIRC P05500550 EC-448
SENSOR POWER/CIRC P06430643 EC-460
TCC SOLENOID/CIRC P07400740 AT- 11 8
Items
(CONSULT-II screen terms) DTC*
1
Reference page
CONSULT-II
GST*
2ECM*3

ON BOARD DIAGNOSTIC (OBD) SYSTEMEC-49
C
DE
F
G H
I
J
K L
M A
EC
Revision: November 2009 2006 QX56
Therefore, when electrical controlled throttle and part of ECM related diagnoses are continuously detected as
NG for 5 trips, ECM warns the driver that engine control system malfunctions and MIL circuit is open by means
of operating fail-safe function.
The fail-safe function also operates when above diagnoses except MIL circuit are detected and demands the
driver to repair the malfunction.
Emission-related Diagnostic InformationUBS00KZR
EMISSION-RELATED DIAGNOSTIC INFORMATION ITEMS
×:Applicable —: Not applicable
Engine operating condition in fail-safe mode
Engine speed will not rise more than 2,500 rpm due to the fuel cut
Items
(CONSULT-II screen terms) DTC*
1
SRT code
Test value/
Te s t l i m i t
(GST only) Trip MIL
Refer-
ence page
CONSULT-II
GST*
2ECM*3
CAN COMM CIRCUIT U1000
1000*5—— 1×EC-151
CAN COMM CIRCUIT U1001
1001*5—— 2—EC-151
CONTROL UNIT(CAN) U1010 1010——1×EC-154
NO DTC IS DETECTED.
FURTHER TESTING
MAY BE REQUIRED. P0000 0000
———
Flashing*7EC-64
A/F SEN1 HTR (B1) P0031 0031—×2×EC-156
A/F SEN1 HTR (B1) P0032 0032—×2×EC-156
HO2S2 HTR (B1) P0037 0037—×2×EC-163
HO2S2 HTR (B1) P0038 0038—×2×EC-163
A/F SEN1 HTR (B2) P0051 0051—×2×EC-156
A/F SEN1 HTR (B2) P0052 0052—×2×EC-156
HO2S2 HTR (B2) P0057 0057—×2×EC-163
HO2S2 HTR (B2) P0058 0058—×2×EC-163
MAF SEN/CIRCUIT P0101 0101——2×EC-171
MAF SEN/CIRCUIT P0102 0102——1×EC-180
MAF SEN/CIRCUIT P0103 0103——1×EC-180
IAT SEN/CIRCUIT P0112 0112——2×EC-188
IAT SEN/CIRCUIT P0113 0113——2×EC-188
ECT SEN/CIRC P0117 0117——1×EC-192
ECT SEN/CIRC P0118 0118——1×EC-192
TP SEN 2/CIRC P0122 0122——1×EC-198
TP SEN 2/CIRC P0123 0123——1×EC-198
ECT SENSOR P0125 0125——2×EC-205
IAT SENSOR P0127 0127——2×EC-208
THERMSTAT FNCTN P0128 0128——2×EC-211
A/F SENSOR1 (B1) P0130 0130—×2×EC-213
A/F SENSOR1 (B1) P0131 0131—×2×EC-223
A/F SENSOR1 (B1) P0132 0132—×2×EC-232
A/F SENSOR1 (B1) P0133 0133××2 ×EC-241
HO2S2 (B1) P0137 0137××2 ×EC-253
HO2S2 (B1) P0138 0138××2 ×EC-264
HO2S2 (B1) P0139 0139××2 ×EC-277
A/F SENSOR1 (B2) P0150 0150—×2×EC-213
A/F SENSOR1 (B2) P0151 0151—×2×EC-223

TROUBLE DIAGNOSIS - SPECIFICATION VALUEEC-141
C
DE
F
G H
I
J
K L
M A
EC
Revision: November 2009 2006 QX56
20. CHECK “A/F ALPHA-B1”, “A/F ALPHA-B2”, AND “B/FUEL SCHDL”
Select “A/F ALPHA-B1 ”, “A/F ALPHA-B2 ”, and “B/FUEL SCHDL ” in “DATA MONITOR (SPEC) ” mode, and
make sure that the each indication is within the SP value.
OK or NG
OK >> INSPECTION END
NG ( “B/FUEL SCHDL ” is more, “A/F ALPHA-B1 ”, “A/F ALPHA-B2 ” are less than the SP value)>>GO TO 21.
21. DISCONNECT AND RECONNECT MASS AIR FLOW SENSOR HARNESS CONNECTOR
1. Stop the engine.
2. Disconnect mass air flow sensor harness connector. Check pin terminal and connector for damage and then reconnect it again.
>> GO TO 22.
22. CHECK “A/F ALPHA-B1”, “A/F ALPHA-B2”
1. Start engine.
2. Select “A/F ALPHA-B1 ”, “A/F ALPHA-B2 ” in “DATA MONITOR (SPEC) ” mode, and make sure that the
each indication is within the SP value.
OK or NG
OK >> 1. Detect malfunctioning part of mass air flow sensor circuit and repair it. Refer to EC-180, "DTC
P0102, P0103 MAF SENSOR" .
2. GO TO 29.
NG >> GO TO 23.
23. CHECK “MAS A/F SE-B1”
Select “MAS A/F SE-B1 ” in “DATA MONITOR (SPEC) ” mode, and
make sure that the indication is within the SP value.
OK or NG
OK >> GO TO 24.
NG (More than the SP value)>>Replace mass air flow sensor, and then GO TO 29.
24. REPLACE ECM
1. Replace ECM.
2. Perform initialization of IVIS(NATS) system and registration of all IVIS(NATS) ignition key IDs. Refer to BL-139, "
ECM Re-communicating Function" .
3. Perform EC-77, "
VIN Registration" .
4. Perform EC-78, "
Accelerator Pedal Released Position Learning" .
5. Perform EC-78, "
Throttle Valve Closed Position Learning" .
6. Perform EC-78, "
Idle Air Volume Learning" .
>> GO TO 29.
PBIB2370E

DTC P0101 MAF SENSOREC-171
C
DE
F
G H
I
J
K L
M A
EC
Revision: November 2009 2006 QX56
DTC P0101 MAF SENSORPFP:22680
Component DescriptionUBS00H0V
The mass air flow sensor is placed in the stream of intake air. It mea-
sures the intake flow rate by measuring a part of the entire intake
flow. The mass air flow sensor controls the temperature of the hot
wire to a certain amount. The heat generated by the hot wire is
reduced as the intake air flows around it. The more air, the greater
the heat loss.
Therefore, the electric current supplied to the hot wire is changed to
maintain the temperature of the hot wire as air flow increases. The
ECM detects the air flow by means of this current change.
CONSULT-II Reference Value in Data Monitor ModeUBS00H0W
Specification data are reference values.
On Board Diagnosis LogicUBS00H0X
BBIA0355E
MONITOR ITEMCONDITION SPECIFICATION
MAS A/F SE-B1 See EC-134, "
TROUBLE DIAGNOSIS - SPECIFICATION VALUE" .
CAL/LD VALUE

Engine: After warming up

Air conditioner switch: OFF

Selector lever: P or N

No load Idle
14% - 33%
2,500 rpm 12% - 25%
MASS AIRFLOW

Engine: After warming up

Air conditioner switch: OFF

Selector lever: P or N

No load Idle
3.0 - 9.0 g·m/s
2,500 rpm 9.0 - 28.0 g·m/s
DTC No. Trouble diagnosis name DTC detecting conditionPossible cause
P0101
0101 Mass air flow sensor circuit
range/performance A)
A high voltage from the sensor is sent to ECM
under light load driving condition.

Harness or connectors
(The sensor circuit is open or
shorted.)

Mass air flow sensor

EVAP control system pressure
sensor

Intake air temperature sensor
B) A low voltage from the sensor is sent to ECM
under heavy load driving condition.

Harness or connectors
(The sensor circuit is open or
shorted.)

Intake air leaks

Mass air flow sensor

EVAP control system pressure
sensor

Intake air temperature sensor

EC-172Revision: November 2009
DTC P0101 MAF SENSOR
2006 QX56
DTC Confirmation ProcedureUBS00H0Y
Perform PROCEDURE FOR MALFUNCTION A first.
If the DTC cannot be confirmed, perform PROCEDURE FOR MALFUNCTION B.
NOTE:
If DTC Confirmation Procedure has been previously conducted, always turn ignition switch OFF and wait at
least 10 seconds before conducting the next test.
PROCEDURE FOR MALFUNCTION A
NOTE:
If engine will not start or stops soon, wait at least 10 seconds with engine stopped (Ignition switch ON) instead
of running engine at idle speed.
With CONSULT-II
1. Turn ignition switch ON.
2. Select “DATA MONITOR ” mode with CONSULT-II.
3. Start engine and warm it up to normal operating temperature.
4. Run engine for at least 10 seconds at idle speed.
5. If 1st trip DTC is detected, go to EC-175, "
Diagnostic Procedure"
.
With GST
Follow the procedure “With CONSULT-II” above.
PROCEDURE FOR MALFUNCTION B
CAUTION:
Always drive vehicle at a safe speed.
With CONSULT-II
1. Turn ignition switch ON.
2. Start engine and warm it up to normal operating temperature.
If engine cannot be started, go to EC-175, "
Diagnostic Procedure" .
3. Select “DATA MONITOR ” mode with CONSULT-II.
4. Check the voltage of “MAS A/F SE-B1” with “DATA MONITOR ”.
5. Increases engine speed to about 4,000 rpm.
6. Monitor the linear voltage rise in response to engine speed increases.
If NG, go to EC-175, "
Diagnostic Procedure" .
If OK, go to following step.
SEF174Y
SEF243Y

DTC P0101 MAF SENSOREC-173
C
DE
F
G H
I
J
K L
M A
EC
Revision: November 2009 2006 QX56
7. Maintain the following conditions for at least 10 consecutive sec-
onds.
8. If 1st trip DTC is detected, go to EC-175, "
Diagnostic Procedure"
.
Overall Function CheckUBS00H0Z
PROCEDURE FOR MALFUNCTION B
Use this procedure to check the overall function of the mass air flow sensor circuit. During this check, a 1st trip
DTC might not be confirmed.
With GST
1. Start engine and warm it up to normal operating temperature.
2. Select Service $01 with GST.
3. Check the mass air flow sensor signal with Service $01.
4. Check for linear mass air flow sensor signal value rise in
response to increases to about 4,000 rpm in engine speed.
5. If NG, go to EC-175, "
Diagnostic Procedure" .
ENG SPEED More than 2,000 rpm
THRTL SEN 1 More than 3V
THRTL SEN 2 More than 3V
Selector lever Suitable position
Driving location Driving vehicle uphill (Increased engine load) will help
maintain the driving conditions required for this test.
PBIB0199E
SEF534P

EC-174Revision: November 2009
DTC P0101 MAF SENSOR
2006 QX56
Wiring DiagramUBS00H10
BBWA1674E

DTC P0101 MAF SENSOREC-175
C
DE
F
G H
I
J
K L
M A
EC
Revision: November 2009 2006 QX56
Specification data are reference values and are measured between each terminal and ground.
CAUTION:
Do not use ECM ground terminals when measuring input/output voltage. Doing so may result in dam-
age to the ECM's transistor. Use a ground other than ECM terminals, such as the ground.
Diagnostic ProcedureUBS00H11
1. INSPECTION START
Which malfunction (A or B) is duplicated?
A or B
A>>GO TO 3.
B>>GO TO 2.
2. CHECK INTAKE SYSTEM
Check the following for connection.

Air duct

Va c u u m h o s e s

Intake air passage between air duct to intake manifold
OK or NG
OK >> GO TO 3.
NG >> Reconnect the parts.
TER-
MINAL NO. WIRE
COLOR ITEM
CONDITION DATA (DC Voltage)
51 W Mass air flow sensor [Engine is running]

Warm-up condition

Idle speed
1.0 - 1.3V
[Engine is running]

Warm-up condition

Engine speed: 2,500 rpm. 1.7 - 2.1V
67 B Sensor ground [Engine is running]

Warm-up condition

Idle speedApproximately 0V
111 W / B ECM relay
(Self shut-off) [Engine is running]
[Ignition switch: OFF]

For a few seconds after turning ignition
switch OFF
0 - 1.5V
[Ignition switch: OFF]

More than a few seconds after turning igni-
tion switch OFF BATTERY VOLTAGE
(11 - 14V)
11 9
120 BR
BR
Power supply for ECM
[Ignition switch: ON] BATTERY VOLTAGE
(11 - 14V)