Ins INFINITI QX56 2004 Factory Service Manual

AT-188
BRAKE SIGNAL CIRCUIT
Revision: August 20072004 QX56
BRAKE SIGNAL CIRCUITPFP:25320
CONSULT-II Reference ValueUCS002IE
Diagnostic ProcedureUCS002IF
1. CHECK CAN COMMUNICATION LINE
Perform the self-diagnosis. Refer to AT-93, "
SELF-DIAGNOSTIC RESULT MODE" .
Is a malfunction in the CAN communication indicated in the results?
YES >> Check CAN communication line. Refer to AT-103, "DTC U1000 CAN COMMUNICATION LINE" .
NO >> GO TO 2.
2. CHECK STOP LAMP SWITCH CIRCUIT
With CONSULT-II
1. Turn ignition switch “ON”. (Do not start engine.)
2. Select “ECU INPUT SIGNALS” in “DATA MONITOR” mode for
“A/T” with CONSULT-II.
3. Read out ON/OFF switching action of the “BRAKE SW”.
OK or NG
OK >>INSPECTION END
NG >> GO TO 3.
3. CHECK STOP LAMP SWITCH
Check continuity between stop lamp switch harness connector termi-
nals 3 and 4.
Check stop lamp switch after adjusting brake pedal — refer to
BR-6, "
BRAKE PEDAL" .
OK or NG
OK >>INSPECTION END
NG >> Check the following items. If NG, repair or replace dam-
aged parts.

Harness for short or open between battery and stop lamp switch.

Harness for short or open between stop lamp switch and combination meter.
Item name Condition Display value
BRAKE SWDepressed brake pedal. ON
Released brake pedal. OFF
PCIA0070E
Condition Continuity
When brake pedal is depressed Yes
When brake pedal is released No
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TOW MODE SWITCH
AT-189
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Revision: August 20072004 QX56
TOW MODE SWITCHPFP:25129
DescriptionUCS002IG
When tow mode switch is “ON”, tow mode switch signals are sent to TCM from combination meter by CAN
communication line.Then it`s a tow mode condition.
Diagnostic ProcedureUCS002IH
1. CHECK CAN COMMUNICATION LINE
Perform the self-diagnosis. Refer to AT - 9 3 , "
SELF-DIAGNOSTIC RESULT MODE" .
Is any malfunction in the CAN communication indicated in the results?
YES >> Check CAN communication line. Refer to AT- 1 0 3 , "DTC U1000 CAN COMMUNICATION LINE" .
NO >> GO TO 2.
2. CHECK POWER SOURCE
1. Turn ignition switch “ON”. (Do not start engine.)
2. Check the voltage between tow mode switch connector terminal
1 and ground.
OK or NG
OK >>INSPECTION END
NG >> GO TO 3.
3. CHECK TOW MODE SWITCH
1. Turn ignition switch “OFF”.
2. Disconnect tow mode switch connector.
3. Check continuity between tow mode switch connector M254 ter-
minals 1 and 2.
OK or NG
OK >> GO TO 4.
NG >> Repair or replace tow mode switch.
4. DETECT MALFUNCTIONING ITEM
Check the following items. If any items are damaged, repair or replace damaged parts.

Harness for short or open between combination meter connector terminal 35 and tow mode switch con-
nector terminal 1.

Harness for short or open between tow mode switch connector terminal 2 and ground.
OK or NG
OK >> GO TO 5.
NG >> Repair or replace damaged parts.
ConditionTo w m o d e
switchData (Approx.)
When ignition switch is turned to “ON”ON 0V
OFF Battery voltage
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Condition Continuity
To w m o d e s w i t c h “ O N ” Ye s
To w m o d e s w i t c h “ O F F ” N o
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AT-190
TOW MODE SWITCH
Revision: August 20072004 QX56
5. CHECK COMBINATION METER
Check the combination meter. Refer to DI-17, "
How to Proceed With Trouble Diagnosis" .
OK or NG
OK >>INSPECTION END
NO >> Repair or replace damaged parts.

AT-192
TROUBLE DIAGNOSIS FOR SYMPTOMS
Revision: August 20072004 QX56
4. CHECK TCM GROUND CIRCUIT
1. Turn ignition switch “OFF”.
2. Disconnect the A/T assembly harness connector.
3. Check the continuity between A/T assembly harness connector
(vehicle side) 5 (B), 10 (B) and ground. Refer to AT - 5 2 , "
Wiring
Diagram — AT —" .
4. If OK, check the harness for short-circuit to ground or the power
source.
OK or NG
OK >> GO TO 5.
NG >> Repair the open or short circuit in the harness or con-
nector.
5. CHECK AT CHECK INDICATOR LAMP CIRCUIT
1. Turn ignition switch “OFF”.
2. Check the combination meter.
Refer to DI-17, "
How to Proceed With Trouble Diagnosis" .
OK or NG
OK >>INSPECTION END
NG >> Repair or replace damaged parts.
Engine Cannot Be Started In “P” or “N” PositionUCS002IJ
SYMPTOM:

Engine cannot be started with selector lever in “P” or “N” position.

Engine can be started with selector lever in “D”or “R” position.
DIAGNOSTIC PROCEDURE
1. CHECK SELF-DIAGNOSIS RESULTS
Perform self-diagnosis. Refer to AT- 9 3 , "
SELF-DIAGNOSTIC RESULT MODE" .
Do the self-diagnosis results indicate PNP switch?
YES >> Check the malfunctioning system. Refer to AT-109, "DTC P0705 PARK/NEUTRAL POSITION
SWITCH" .
NO >> GO TO 2.
2. CHECK CONTROL CABLE
Check the control cable.

Refer to AT-234, "Checking of A/T Position" .
OK or NG
OK >> GO TO 3.
NG >> Adjust control cable. Refer to AT-234, "
Adjustment of A/
T Position" .
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TROUBLE DIAGNOSIS FOR SYMPTOMS
AT-193
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Revision: August 20072004 QX56
3. CHECK STARTING SYSTEM
Check the starting system. Refer to SC-10, "
STARTING SYSTEM" .
OK or NG
OK >>INSPECTION END
NG >> Repair or replace damaged parts.
In “P” Position, Vehicle Moves When PushedUCS002IK
SYMPTOM:
Even though the selector lever is set in the “P” position, the parking mechanism is not actuated,
allowing the vehicle to be moved when it is pushed.
DIAGNOSTIC PROCEDURE
1. CHECK PNP SWITCH CIRCUIT
Perform self-diagnosis. Refer to AT- 9 3 , "
SELF-DIAGNOSTIC RESULT MODE" .
Do the self-diagnosis results indicate PNP switch?
YES >> Check the malfunctioning system. Refer to AT-109, "DTC P0705 PARK/NEUTRAL POSITION
SWITCH" .
NO >> GO TO 2.
2. CHECK CONTROL CABLE
Check the control cable.

Refer to AT- 2 3 4 , "Checking of A/T Position" .
OK or NG
OK >> GO TO 3.
NG >> Adjust control cable. Refer to AT-234, "
Adjustment of A/
T Position" .
3. CHECK A/T FLUID CONDITION
1. Remove oil pan. Refer to AT-241, "
Control Valve With TCM and A/T Fluid Temperature Sensor 2" .
2. Check A/T fiuid condition. Refer to AT- 5 8 , "
Fluid Condition
Check" .
OK or NG
OK >>INSPECTION END
NG >> GO TO 4.
4. DETECT MALFUNCTIONING ITEM

Check the malfunction items. If any items are damaged, repair or replace damaged parts. Refer to AT-68,
"Symptom Chart" (Symptom No.58).
OK or NG
OK >>INSPECTION END
NG >> Repair or replace damaged parts.
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TROUBLE DIAGNOSIS FOR SYMPTOMS
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5. CHECK SYMPTOM
Check again. Refer to AT- 6 2 , "
Check at Idle" .
OK or NG
OK >>INSPECTION END
NG >> GO TO 6.
6. PERFORM TCM INSPECTION
1. Perform TCM input/output signals inspection. Refer to AT-90, "
TCM Input/Output Signal Reference Val-
ues" .
2. If NG, recheck A/T assembly harness connector terminals for damage or loose connection with harness
connector.
OK or NG
OK >>INSPECTION END
NG >> Repair or replace damaged parts.
Large Shock (“N” to “D” Position)UCS002IM
SYMPTOM:
A noticeable shock occurs when the selector lever is shifted from the “N” to “D” position.
DIAGNOSTIC PROCEDURE
1. CHECK SELF-DIAGNOSTIC RESULTS
Perform self-diagnosis. Refer to AT- 9 3 , "
SELF-DIAGNOSTIC RESULT MODE" .
Do the self-diagnostic results indicate A/T fluid temperature sensor, engine speed signal, accelerator pedal
position sensor, ATF pressure switch 1, front brake solenoid valve, CAN communication line?
YES >> Check the malfunctioning system. Refer to AT-131, "DTC P1710 A/T FLUID TEMPERATURE
SENSOR CIRCUIT" , AT-115, "DTC P0725 ENGINE SPEED SIGNAL" ., AT- 1 2 9 , "DTC P1705
THROTTLE POSITION SENSOR" , AT-175, "DTC P1841 ATF PRESSURE SWITCH 1" , AT-
151, "DTC P1757 FRONT BRAKE SOLENOID VALVE" , AT- 1 0 3 , "DTC U1000 CAN COMMUNI-
CATION LINE" .
NO >> GO TO 2.
2. ENGINE IDLE SPEED
Check the engine idle speed. Refer to EC-32, "
Idle Speed and Ignition Timing Check" .
OK or NG
OK >> GO TO 3.
NG >> Repair.
3. CHECK CONTROL CABLE
Check the control cable.

Refer to AT- 2 3 4 , "Checking of A/T Position" .
OK or NG
OK >> GO TO 4.
NG >> Adjust control cable. Refer to AT-234, "
Adjustment of A/
T Position" .
LCIA0324E

TROUBLE DIAGNOSIS FOR SYMPTOMS
AT-197
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Revision: August 20072004 QX56
8. CHECK A/T FLUID CONDITION
1. Remove oil pan. Refer to AT-241, "
Control Valve With TCM and A/T Fluid Temperature Sensor 2" .
2. Check A/T fluid condition. Refer to AT- 5 8 , "
Fluid Condition
Check" .
OK or NG
OK >> GO TO 10.
NG >> GO TO 9.
9. DETECT MALFUNCTIONING ITEM

Check the malfunction items. If any items are damaged, repair or replace damaged parts. Refer to AT-68,
"Symptom Chart" (Symptom No.1).
OK or NG
OK >> GO TO 10.
NG >> Repair or replace damaged parts.
10. CHECK SYMPTOM
Check again. Refer to AT- 6 2 , "
Check at Idle" .
OK or NG
OK >>INSPECTION END
NG >> GO TO 11.
11 . PERFORM TCM INSPECTION
1. Perform TCM input/output signals inspection. Refer to AT-90, "
TCM Input/Output Signal Reference Val-
ues" .
2. If NG, recheck A/T assembly harness connector terminals for damage or loose connection with harness
connector.
OK or NG
OK >>INSPECTION END
NG >> Repair or replace damaged parts.
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AT-200
TROUBLE DIAGNOSIS FOR SYMPTOMS
Revision: August 20072004 QX56
9. CHECK A/T FLUID CONDITION
1. Remove oil pan. Refer to AT-241, "
Control Valve With TCM and A/T Fluid Temperature Sensor 2" .
2. Check A/T fluid condition. Refer to AT- 5 8 , "
Fluid Condition
Check" .
OK or NG
OK >> GO TO 10.
NG >> GO TO 13.
10. DETECT MALFUNCTIONING ITEM

Check the malfunction items. If any items are damaged, repair or replace damaged parts. Refer to AT-68,
"Symptom Chart" (Symptom No.43).
OK or NG
OK >> GO TO 11.
NG >> Repair or replace damaged parts.
11 . CHECK SYMPTOM
Check again. Refer to AT-62, "
Check at Idle" .
OK or NG
OK >>INSPECTION END
NG >> GO TO 12.
12. PERFORM TCM INSPECTION
1. Perform TCM input/output signals inspection. Refer to AT- 9 0 , "
TCM Input/Output Signal Reference Val-
ues" .
2. If NG, recheck A/T assembly harness connector terminals for damage or loose connection with harness
connector.
OK or NG
OK >>INSPECTION END
NG >> Repair or replace damaged parts.
13. DETECT MALFUNCTIONING ITEM

Check the malfunction items. If any items are damaged, repair or replace damaged parts. Refer to AT-68,
"Symptom Chart" (Symptom No.43).
OK or NG
OK >> GO TO 11.
NG >> Repair or replace damaged parts.
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TROUBLE DIAGNOSIS FOR SYMPTOMS
AT-203
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Revision: August 20072004 QX56
9. DETECT MALFUNCTIONING ITEM

Check the malfunction items. If any items are damaged, repair or replace damaged parts. Refer to AT-68,
"Symptom Chart" (Symptom No.43).
OK or NG
OK >> GO TO 10.
NG >> Repair or replace damaged parts.
10. CHECK SYMPTOM
Check again. Refer to AT- 6 2 , "
Check at Idle" .
OK or NG
OK >>INSPECTION END
NG >> GO TO 11.
11 . PERFORM TCM INSPECTION
1. Perform TCM input/output signals inspection. Refer to AT-90, "
TCM Input/Output Signal Reference Val-
ues" .
2. If NG, recheck A/T assembly harness connector terminals for damage or loose connection with harness
connector.
OK or NG
OK >>INSPECTION END
NG >> Repair or replace damaged parts.
12. DETECT MALFUNCTIONING ITEM

Check the malfunction items. If any items are damaged, repair or replace damaged parts. Refer to AT-68,
"Symptom Chart" (Symptom No.43).
OK or NG
OK >> GO TO 10.
NG >> Repair or replace damaged parts.
Vehicle Cannot Be Started From D1UCS002IP
SYMPTOM:
Vehicle cannot be started from D1 on cruise test - Part 1.
DIAGNOSTIC PROCEDURE
1. CONFIRM THE SYMPTOM
Check if vehicle creeps in “R” position.
OK or NG
OK >> GO TO 2.
NG >> Refer to AT-198, "
Vehicle Does Not Creep Backward In “R” Position" .
2. CHECK SELF-DIAGNOSTIC RESULTS
Perform self-diagnosis. Refer to AT- 9 3 , "
SELF-DIAGNOSTIC RESULT MODE" .
Is any malfunction detected by self-diagnostic results?
YES >> Check the malfunctioning system.
NO >> GO TO 3.

TROUBLE DIAGNOSIS FOR SYMPTOMS
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Revision: August 20072004 QX56
7. DETECT MALFUNCTIONING ITEM
1. Check control valve with TCM. Refer to AT-241, "
Control Valve With TCM and A/T Fluid Temperature Sen-
sor 2" .
2. Disassemble A/T. Refer to AT- 2 7 3 , "
Disassembly" .
3. Check the following items:
–Oil pump assembly. Refer to AT-290, "Oil Pump" .
–Power train system. Refer to AT- 2 7 3 , "Disassembly" .
–Transmission case. Refer to AT - 2 7 3 , "Disassembly" .
OK or NG
OK >> GO TO 8.
NG >> Repair or replace damaged parts.
8. CHECK A/T FLUID CONDITION
1. Remove oil pan. Refer to AT-241, "
Control Valve With TCM and A/T Fluid Temperature Sensor 2" .
2. Check A/T fluid condition. Refer to AT- 5 8 , "
Fluid Condition
Check" .
OK or NG
OK >> GO TO 9.
NG >> GO TO 12.
9. DETECT MALFUNCTIONING ITEM

Check the malfunction items. If any items are damaged, repair or replace damaged parts. Refer to AT-68,
"Symptom Chart" (Symptom No.23).
OK or NG
OK >> GO TO 10.
NG >> Repair or replace damaged parts.
10. CHECK SYMPTOM
Check again. Refer to AT- 6 3 , "
Cruise Test - Part 1" , AT - 6 5 , "Cruise Test - Part 2" .
OK or NG
OK >>INSPECTION END
NG >> GO TO 11.
11 . PERFORM TCM INSPECTION
1. Perform TCM input/output signals inspection. Refer to AT-90, "
TCM Input/Output Signal Reference Val-
ues" .
2. If NG, recheck A/T assembly harness connector terminals for damage or loose connection with harness
connector.
OK or NG
OK >>INSPECTION END
NG >> Repair or replace damaged parts.
SCIA5199E