Air INFINITI QX56 2004 Factory Service Manual

DTC P0327, P0328, P0332, P0333 KS
EC-253
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Revision: August 20072004 QX56
5. CHECK GROUND CONNECTIONS
1. Turn ignition switch OFF.
2. Loosen and retighten three ground screws on the body.
Refer to EC-133, "
Ground Inspection" .
OK or NG
OK >> GO TO 6.
NG >> Repair or replace ground connections.
6. CHECK KNOCK SENSOR SHIELD CIRCUIT FOR OPEN AND SHORT
1. Turn ignition switch OFF.
2. Disconnect knock sensor harness connector.
3. Check harness continuity between knock sensor terminal 2 and body ground. Refer to Wiring Diagram.
4. Also check harness for short to power.
OK or NG
OK >> GO TO 8.
NG >> GO TO 7.
7. DETECT MALFUNCTIONING PART
Check the following.

Harness connectors F26, F101

Harness connectors F14, E5

Harness for open or short between knock sensor terminal 2 and body ground
>> Repair open circuit or short power in harness or connectors.
8. CHECK INTERMITTENT INCIDENT
Refer to EC-127, "
TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT" .
>>INSPECTION END
BBIA0354E
Continuity should exist.

DTC P0335 CKP SENSOR (POS)
EC-257
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Revision: August 20072004 QX56
Specification data are reference values and are measured between each terminal and ground.
Pulse signal is measured by CONSULT-II.
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.
: Average voltage for pulse signal (Actual pulse signal can be confirmed by oscilloscope.)
Diagnostic ProcedureUBS00H45
1. CHECK GROUND CONNECTIONS
1. Turn ignition switch OFF.
2. Loosen and retighten three ground screws on the body.
Refer to EC-133, "
Ground Inspection" .
OK or NG
OK >> GO TO 2.
NG >> Repair or replace ground connections.
TER-
MINAL
NO.WIRE
COLORITEM CONDITION DATA (DC Voltage)
13 OCrankshaft position sensor
(POS)[Engine is running]

Warm-up condition

Idle speed
NOTE:
The pulse cycle changes depending on rpm at
idle. 1.0 - 2.0V
[Engine is running]

Engine speed is 2,000 rpm.1.0 - 2.0V
PBIB1041E
PBIB1042E
BBIA0354E

EC-258Revision: August 2007
DTC P0335 CKP SENSOR (POS)
2004 QX56
2. CHECK CRANKSHAFT POSITION (CKP) SENSOR (POS) POWER SUPPLY CIRCUIT
1. Disconnect crankshaft position (CKP) sensor (POS) harness
connector.
2. Turn ignition switch ON.
3. Check voltage between CKP sensor (POS) terminal 3 and
ground with CONSULT-II or tester.
4. Also check harness for short to ground and short to power.
OK or NG
OK >> GO TO 4.
NG >> GO TO 3.
3. DETECT MALFUNCTIONING PART
Check the following.

Harness connectors F32, E2

Harness for open or short between crankshaft position sensor (POS) and ECM

Harness for open or short between crankshaft position sensor (POS) and IPDM E/R
>> Repair open circuit or short to ground or short to power in harness or connectors.
4. CHECK CKP SENSOR (POS) GROUND CIRCUIT FOR OPEN AND SHORT
1. Turn ignition switch OFF.
2. Check harness continuity between CKP sensor (POS) terminal 1 and body ground. Refer to Wiring Dia-
gram.
3. Also check harness for short to power.
OK or NG
OK >> GO TO 6.
NG >> GO TO 5.
5. DETECT MALFUNCTIONING PART
Check the following.

Harness connectors F32, E2

Harness for open or short between crankshaft position sensor (POS) and ground
>> Repair open circuit or short to power in harness or connectors.
BBIA0367E
Voltage: Battery voltage
SEF 4 81 Y
Continuity should exist.

DTC P0335 CKP SENSOR (POS)
EC-259
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Revision: August 20072004 QX56
6. CHECK CKP SENSOR (POS) INPUT SIGNAL CIRCUIT FOR OPEN AND SHORT
1. Disconnect ECM harness connector.
2. Check harness continuity between ECM terminal 13 and CKP sensor (POS) terminal 2.
Refer to Wiring Diagram.
3. Also check harness for short to ground and short to power.
OK or NG
OK >> GO TO 7.
NG >> Repair open circuit or short to ground or short to power in harness or connectors.
7. CHECK CRANKSHAFT POSITION SENSOR (POS)
Refer to EC-260, "
Component Inspection" .
OK or NG
OK >> GO TO 8.
NG >> Replace crankshaft position sensor (POS).
8. CHECK GEAR TOOTH
Visually check for chipping signal plate gear tooth.
OK or NG
OK >> GO TO 9.
NG >> Replace the signal plate.
9. CHECK INTERMITTENT INCIDENT
Refer to EC-127, "
TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT" .
>>INSPECTION END Continuity should exist.

DTC P0340 CAMSHAFT POSITION (CMP) SENSOR (PHASE)
EC-263
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Revision: August 20072004 QX56
Specification data are reference values and are measured between each terminal and ground.
Pulse signal is measured by CONSULT-II.
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.
: Average voltage for pulse signal (Actual pulse signal can be confirmed by oscilloscope.)
Diagnostic ProcedureUBS00H4C
1. CHECK STARTING SYSTEM
Turn ignition switch to START position.
Ye s o r N o
Yes >> GO TO 2.
No >> Check starting system. (Refer to SC-10, "
STARTING SYSTEM" .)
2. CHECK GROUND CONNECTIONS
1. Turn ignition switch OFF.
2. Loosen and retighten three ground screws on the body.
Refer to EC-133, "
Ground Inspection" .
OK or NG
OK >> GO TO 3.
NG >> Repair or replace ground connections.
TER-
MINAL
NO.WIRE
COLORITEM CONDITION DATA (DC Voltage)
14 YCamshaft position sensor
(PHASE)[Engine is running]

Warm-up condition

Idle speed
NOTE:
The pulse cycle changes depending on rpm at
idle.1.0 - 4.0V
[Engine is running]

Engine speed is 2,000 rpm.1.0 - 4.0V
PBIB1039E
PBIB1040E
Does the engine turn over?
Does the starter motor operate?
BBIA0354E

EC-264Revision: August 2007
DTC P0340 CAMSHAFT POSITION (CMP) SENSOR (PHASE)
2004 QX56
3. CHECK CAMSHAFT POSITION (CMP) SENSOR (PHASE) POWER SUPPLY CIRCUIT
1. Disconnect camshaft position (CMP) sensor (PHASE) harness
connector.
2. Turn ignition switch ON.
3. Check voltage between CMP sensor (PHASE) terminal 3 and
ground with CONSULT-II or tester.
4. Also check harness for short to ground and short to power.
OK or NG
OK >> GO TO 5.
NG >> GO TO 4.
4. DETECT MALFUNCTIONING PART
Check the following.

Harness connectors F32, E2

Harness for open or short between camshaft position sensor (PHASE) and ECM

Harness for open or short between camshaft position sensor (PHASE) and IPDM E/R
>> Repair open circuit or short to ground or short to power in harness or connectors.
5. CHECK CMP SENSOR (PHASE) GROUND CIRCUIT FOR OPEN AND SHORT
1. Turn ignition switch OFF.
2. Check harness continuity between CMP sensor (PHASE) terminal 1 and body ground.
3. Also check harness for short to power.
OK or NG
OK >> GO TO 7.
NG >> GO TO 6.
6. DETECT MALFUNCTIONING PART
Check the following.

Harness connectors F32, E2

Harness for open or short between CMP sensor (PHASE) and body ground
>> Repair open circuit or short to power in harness or connectors.
BBIA0372E
Voltage: Battery voltage
SEF 4 81 Y
Continuity should exist.

DTC P0340 CAMSHAFT POSITION (CMP) SENSOR (PHASE)
EC-265
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Revision: August 20072004 QX56
7. CHECK CMP SENSOR (PHASE) INPUT SIGNAL CIRCUIT FOR OPEN AND SHORT
1. Disconnect ECM harness connector.
2. Check harness continuity between ECM terminal 14 and CMP sensor (PHASE) terminal 2.
Refer to Wiring Diagram.
3. Also check harness for short to ground or short to power.
OK or NG
OK >> GO TO 8.
NG >> Repair open circuit or short to ground or short to power in harness or connectors.
8. CHECK CAMSHAFT POSITION SENSOR (PHASE)
Refer to EC-266, "
Component Inspection" .
OK or NG
OK >> GO TO 9.
NG >> Replace camshaft position sensor (PHASE).
9. CHECK INTERMITTENT INCIDENT
Refer to EC-127, "
TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT" .
>>INSPECTION END Continuity should exist.

DTC P0420, P0430 THREE WAY CATALYST FUNCTION
EC-267
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Revision: August 20072004 QX56
DTC P0420, P0430 THREE WAY CATALYST FUNCTIONPFP:20905
On Board Diagnosis LogicUBS00H4F
The ECM monitors the switching frequency ratio of air fuel sensor
(A/F) sensor 1 and heated oxygen sensor 2.
A three way catalyst (manifold) with high oxygen storage capacity
will indicate a low switching frequency of heated oxygen sensor 2.
As oxygen storage capacity decreases, the heated oxygen sensor 2
switching frequency will increase.
When the frequency ratio of air fuel ratio (A/F) sensor 1 and heated
oxygen sensor 2 approaches a specified limit value, the three way
catalyst (manifold) malfunction is diagnosed.
DTC Confirmation ProcedureUBS00H4G
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.
WITH CONSULT-II
TESTING CONDITION:
Do not hold engine speed for more than the specified minutes below.
1. Turn ignition switch ON and select “DATA MONITOR” mode with
CONSULT-II.
2. Start engine and warm it up to the normal operating tempera-
ture.
3. Turn ignition switch OFF and wait at least 10 seconds.
4. Start engine and keep the engine speed between 3,500 and
4,000 rpm for at least 1 minute under no load.
5. Let engine idle for 1 minute.
6. Make sure that “COOLAN TEMP/S” indicates more than 70°C
(158°F).
If not, warm up engine and go to next step when “COOLAN
TEMP/S” indication reaches to 70°C (158°F).
7. Open engine hood.
PBIB2055E
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P0420
0420
(Bank 1)
Catalyst system effi-
ciency below threshold

Three way catalyst (manifold) does not oper-
ate properly.

Three way catalyst (manifold) does not have
enough oxygen storage capacity.

Three way catalyst (manifold)

Exhaust tube

Intake air leaks

Fuel injector

Fuel injector leaks

Spark plug

Improper ignition timing P0430
0430
(Bank 2)
SEF 1 89 Y

DTC P0420, P0430 THREE WAY CATALYST FUNCTION
EC-269
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Revision: August 20072004 QX56
Diagnostic ProcedureUBS00H4I
1. CHECK EXHAUST SYSTEM
Visually check exhaust tubes and muffler for dent.
OK or NG
OK >> GO TO 2.
NG >> Repair or replace.
2. CHECK EXHAUST GAS LEAK
1. Start engine and run it at idle.
2. Listen for an exhaust gas leak before the three way catalyst (manifold).
OK or NG
OK >> GO TO 3.
NG >> Repair or replace.
3. CHECK INTAKE AIR LEAK
Listen for an intake air leak after the mass air flow sensor.
OK or NG
OK >> GO TO 4.
NG >> Repair or replace.
4. CHECK IGNITION TIMING
Check the following items. Refer to EC-79, "
Basic Inspection" .
OK or NG
OK >> GO TO 5.
NG >> Follow the EC-79, "
Basic Inspection" .
PBIB1216E
Items Specifications
Target idle speed 650 ± 50 rpm (in P or N position)
Ignition timing 15 ± 5° BTDC (in P or N position)

DTC P0441 EVAP CONTROL SYSTEM
EC-271
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Revision: August 20072004 QX56
DTC P0441 EVAP CONTROL SYSTEMPFP:14950
System DescriptionUBS00H4J
NOTE:
If DTC P0441 is displayed with other DTC such as P2122, P2123, P2127, P2128 or P2138, first perform
trouble diagnosis for other DTC.
In this evaporative emission (EVAP) control system, purge flow occurs during non-closed throttle conditions.
Purge volume is related to air intake volume. Under normal purge conditions (non-closed throttle), the EVAP
canister purge volume control solenoid valve is open to admit purge flow. Purge flow exposes the EVAP con-
trol system pressure sensor to intake manifold vacuum.
On Board Diagnosis LogicUBS00H4K
Under normal conditions (non-closed throttle), sensor output voltage indicates if pressure drop and purge flow
are adequate. If not, a malfunction is determined.
DTC Confirmation ProcedureUBS00H4L
CAUTION:
Always drive vehicle at a safe speed.
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.
TESTING CONDITION:
Always perform test at a temperature of 5°C (41°F) or more.
PBIB1026E
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P0441
0441EVAP control system
incorrect purge flowEVAP control system does not operate prop-
erly, EVAP control system has a leak between
intake manifold and EVAP control system pres-
sure sensor.

EVAP canister purge volume control
solenoid valve stuck closed

EVAP control system pressure sensor
and the circuit

Loose, disconnected or improper con-
nection of rubber tube

Blocked rubber tube

Cracked EVAP canister

EVAP canister purge volume control
solenoid valve circuit

Accelerator pedal position sensor

Blocked purge port

EVAP canister vent control valve