ignition INFINITI QX56 2008 Factory Service Manual

TRANSFER CONTROL UNITDLN-85
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10 L/W Transfer dropping resistor • Vehicle stopped
• Engine running
• A/T selector lever
“N” position
• Brake pedal de- pressed 4WD shift switch: AUTO
4 - 14V
4WD shift switch: 2WD, 4H or 4LO Less than 1V
11 L 4WD shift indicator lamp
(Lock indicator lamp) Lock indicator lamp of 4WD shift indicator lamp: OFF
Battery voltage
Lock indicator lamp of 4WD shift indicator lamp: ON 0V
12 W/G 4LO indicator lamp 4LO indicator lamp: OFF
Battery voltage
4LO indicator lamp: ON 0V
13 G/B Transfer shift low relay • Vehicle stopped
• Engine running
• A/T selector lever
“N” position
• Brake pedal de-
pressed 4WD shift switch: 4LO to 4H (“Wait” func-
tion is operating.)
Battery voltage
Except the above 0V
14 LG Transfer motor relay • Accelerator pedal
depressed
• Vehicle stopped
• Engine running
• Brake pedal de- pressed 4WD shift switch: 2WD
Battery voltage
4WD shift switch: AUTO or 4LO (A/T selec-
tor lever “P” or “N” position) Battery voltage
(0V for approx.
2 sec. after
shifting to “P”
and “N”.)
4WD shift switch: AUTO or 4LO (Except for
A/T selector lever “P” or “N” position) 0V
4WD shift switch: 4H (A/T selector lever
“P” position) Battery voltage
(0V for approx.
2 sec. after
shifting to “P”.)
4WD shift switch: 4H (Except for A/T selec-
tor lever “P” position) 0V
15 L/B ATP warning lamp ATP indicator lamp: ON
0V
ATP indicator lamp: OFF Battery voltage
16 Y/R Power supply Ignition switch: ON
Battery voltage
Ignition switch: OFF 0V
18 O 4WD shift switch
(4H) Ignition switch: ON4WD shift switch: 4H
Battery voltage
4WD shift switch: 2WD, AUTO or 4LO 0V
19 L Clutch pressure solenoid
valve • Vehicle stopped
• Engine running
• A/T selector lever
“N” position
• Brake pedal de- pressed 4WD shift switch: AUTO
1.5 - 3V
4WD shift switch: 2WD, 4H or 4LO Less than 1V
21 BR 4WD shift indicator lamp
(AUTO indicator lamp) • AUTO indicator lamp of 4WD shift indicator lamp: OFF
Battery voltage
AUTO indicator lamp of 4WD shift indicator lamp: ON 0V
22 Y/R Power supply Ignition switch: ON
Battery voltage
Ignition switch: OFF 0V
23 R 4WD shift switch
(4LO)
Ignition switch: ON4WD shift switch: 4LO
Battery voltage
4WD shift switch: 2WD, AUTO or 4H 0V
24 LG/R 4WD shift switch
(AUTO)
Ignition switch: ON4WD shift switch: AUTO
Battery voltage
4WD shift switch: 2WD, 4H or 4LO 0V
Te r m i n a l
Wire
color Item
ConditionData (Approx.)
Revision: March 2010 2008 QX56

DLN-86
< ECU DIAGNOSIS >[ATX14B]
TRANSFER CONTROL UNIT
25 V Neutral-4LO switch• Vehicle stopped
• Engine running
• A/T selector lever
“N” position
• Brake pedal de- pressed 4WD shift switch: 2WD, AUTO or 4H Battery voltage
4WD shift switch: 4H to 4LO (While actua-
tor motor is operating.)
Battery voltage
→
0V
4WD shift switch: 4LO to 4H (While actua-
tor motor is operating.) 0V
→ Battery
voltage
4WD shift switch: 4LO 0V
27 W/L Actuator position switch 2
(High) • Vehicle stopped
• Engine running
• A/T selector lever
“N” position
• Brake pedal de-
pressed 4WD shift switch: 4H, AUTO or 2WD 0V
4WD shift switch: 4LO
Battery voltage
28 B/G Sensor ground Always0V
29 L/W Ignition switch monitor Ignition switch: ON
Battery voltage
Ignition switch: OFF 0V
30 SB Shut off relay Ignition switch: ON
0V
Ignition switch: OFF Battery voltage
31 G Transfer fluid temperature
sensor
Ignition switch: ONTransfer fluid temperature approx. 20
°C
(68 °F) 1.1V
Transfer fluid temperature approx. 80 °C
(176 °F) 0.3V
33 R/L Transfer shift high relay
monitor • Vehicle stopped
• Engine running
• A/T selector lever
“N” position
• Brake pedal de- pressed 4WD shift switch: 4H to 4LO (“Wait” func-
tion is operating.)
Battery voltage
Except the above 0V
34 BR Clutch pressure switch • Vehicle stopped
• Engine running
• A/T selector lever
“D” position 4WD shift switch: AUTO or 4H (“Wait” func-
tion is not operating.)
0V
• Vehicle stopped
• Engine running 4WD shift switch: 2WD (“Wait” function is
not operating.)
Battery voltage
35 BR/
W Line pressure switch • Ignition switch: ON
• A/T selector lever “D” position
• 4WD shift switch: AUTO
0V
• After the vehicle has been left at
room temperature
for 5 minutes and
more with ignition
switch in “OFF” po-
sition. • Ignition switch: ON
• A/T selector lever: “P” or "N" position
• 4WD shift switch: other than AUTO
Battery voltage
40 L ATP switch • Vehicle stopped
• Engine running
• A/T selector lever
“N”
• Brak e

pedal de-
pressed 4WD shift switch: 4H to 4LO or 4LO to 4H
(While actuator motor is operating.)
0V
Except the above Battery voltage
Te r m i n a l
Wire
color Item
ConditionData (Approx.)
Revision: March 2010 2008 QX56

TRANSFER CONTROL UNITDLN-87
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CAUTION:
When using a circuit tester to measure voltage for inspection , be sure not to extend forcibly any connector terminals.
NOTE:
Data are reference value and are measured between each terminal and ground.
41 RTransfer motor relay moni-
tor • Accelerator pedal
depressed
• Vehicle stopped
• Engine running
• Brake pedal de- pressed 4WD shift switch: 2WD
0V
4WD shift switch: AUTO or 4LO (A/T selec-
tor lever “P” or “N” position) 0V
(Battery volt-
age for approx.
2 sec. after
shifting to “P”
and “N”.)
4WD shift switch: AUTO or 4LO (Except for
A/T selector lever “P” or “N” position) Battery voltage
4WD shift switch: 4H (A/T selector lever
“P” position) 0V
(Battery volt-
age for approx.
2 sec. after
shifting to “P”.)
4WD shift switch: 4H (Except for A/T selec-
tor lever “P” position) Battery voltage
42 P/G Transfer shift low relay
monitor • Vehicle stopped
• Engine running
• A/T selector lever
“N” position
• Brake pedal de-
pressed 4WD shift switch: 4LO to 4H (“Wait” func-
tion is operating.)
Battery voltage
Except the above 0V
43 G/Y Wait detection switch • Vehicle stopped
• Engine running
• A/T selector lever
“N” position
• Brake pedal de- pressed 4WD shift switch: 2WD, AUTO or 4H Battery voltage
4WD shift switch: 4H to 4LO (While actua-
tor motor is operating.)
Battery voltage
→ 0V
4WD shift switch: 4LO to 4H (While actua-
tor motor is operating.) 0V
→ Battery
voltage
4WD shift switch: 4LO 0V
44 LG/B Actuator position switch 1
(Low) • Vehicle stopped
• Engine running
• A/T selector lever
“N” position
• Brake pedal de- pressed 4WD shift switch: 4LO
0V
4WD shift switch: 2WD, AUTO or 4H Battery voltage
45 B Ground Always0V
47 W Power supply
(Memory back-up) Ignition switch: ON
Battery voltage
Ignition switch: OFF Battery voltage
Te r m i n a l
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color Item
ConditionData (Approx.)
Revision: March 2010 2008 QX56

DLN-100
< SYMPTOM DIAGNOSIS >[ATX14B]
4WD SYSTEM SYMPTOMS
SYMPTOM DIAGNOSIS
4WD SYSTEM SYMPTOMS
Symptom TableINFOID:0000000001737182
If 4WD warning lamp turns ON, perform self-diagnosis. Refer to DLN-18, "CONSULT-III Function (ALL MODE AWD/4WD)".
NOTE:
• Light tight-corner braking symptom may occur depending on driving conditions in AUTO mode. This is not a
malfunction.
• Heavy tight-corner braking symptom occurs when vehicle is driven in the following conditions: 4WD shift
switch is 4H or 4LO, steering wheel is turned fully to either side.
Symptom ConditionReference page
4WD shift indicator lamp and 4LO indicator lamp do not turn ON
(4WD shift indicator lamp and 4LO indicator lamp check) Ignition switch: ON
DLN-101
4WD warning lamp does not turn ON
(4WD warning lamp check) Ignition switch: ON
DLN-103
4WD shift indicator lamp or 4LO indicator lamp does not change Engine runningDLN-105
ATP warning lamp does not turn ON Engine runningDLN-107
4WD shift indicator lamp keeps flashing Engine runningDLN-109
4WD warning lamp flashes rapidly (2 times/second) While drivingDLN-110
4WD warning lamp flashes slowly
(1 time/2 seconds) While driving
DLN-111
Heavy tight-corner braking symptom occurs
(See NOTE.) • While driving
•AUTO mode
• Steering wheel is turned fully
to either side DLN-112
ATP switch does not operate
Engine runningDLN-114
4WD system does not operate While drivingDLN-116
Revision: March 2010 2008 QX56

4WD SHIFT INDICATOR LAMP AND 4LO INDICATOR LAMP DO NOT TURN ON
DLN-101
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4WD SHIFT INDICATOR LAMP AND 4LO INDICATOR LAMP DO NOT
TURN ON
DescriptionINFOID:0000000001737183
4WD shift indicator lamp and 4LO indicator lamp do not turn ON for approx. 1 second when turning ignition
switch to ON.
Diagnosis ProcedureINFOID:0000000001737184
1.CHECK TRANSFER CONTROL UNIT PO WER SUPPLY AND GROUND CIRCUITS
Refer to DLN-22, "
Diagnosis Procedure".
Are the inspection results normal?
YES >> GO TO 2.
NO >> Repair as necessary.
2.CHECK COMBINATION METER POWER SUPPLY AND GROUND CIRCUITS
Refer to MWI-30, "
COMBINATION METER : Diagnosis Procedure".
Are the inspection results normal?
YES >> GO TO 3.
NO >> Perform repairs as necessary.
3.CHECK HARNESS BETWEEN TR ANSFER CONTROL UNIT AND COMBINATION METER
1. Turn ignition switch OFF. (Stay for at least 5 seconds.)
2. Disconnect transfer control unit harness connector.
3. Check continuity between the following terminals.
- Transfer control unit harness connector E142 (B) terminal 2 and combination meter harness connector M24 (A) terminal 38.
- Transfer control unit harness connector E142 (B) terminal 11 and combination meter harness connector M24 (A) terminal 29.
- Transfer control unit harness connector E142 (B) terminal 12 and combination meter harness connector M24 (A) terminal 39.
- Transfer control unit harness connector E142 (B) terminal 21
and combination meter harness connector M24 (A) terminal 28.
Also check harness for short to ground and short to power.
Are the inspection results normal?
YES >> GO TO 4.
NO >> Repair or replace damaged parts.
4.CHECK INDICATOR LAMP CIRCUIT
1. Connect combination meter harness connector.
2. Turn ignition switch ON.
3. Ground the following terminals using suitable wiring.
- Transfer control unit harness connector E142 terminal 2 and ground.
- Transfer control unit harness connector E142 terminal 11 and
ground.
- Transfer control unit harness connector E142 terminal 12 and
ground.
- Transfer control unit harness connector E142 terminal 21 and
ground.
Do indicator lamps turn on?
YES >> GO TO 5.
NO >> Replace combination meter. Refer to MWI-76, "
Removal
and Installation".
Continuity should exist.
AWDIA0184ZZ
SDIA2772E
Revision: March 2010
2008 QX56

4WD WARNING LAMP DOES NOT TURN ONDLN-103
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4WD WARNING LAMP DOES NOT TURN ON
DescriptionINFOID:0000000001737185
4WD warning lamp does not turn ON when turning ignition switch to ON.
Diagnosis ProcedureINFOID:0000000001737186
1.CHECK TRANSFER CONTROL UNIT PO WER SUPPLY AND GROUND CIRCUITS
Refer to DLN-22, "
Diagnosis Procedure".
Are the inspection results normal?
YES >> GO TO 2.
NO >> Repair as necessary.
2.CHECK COMBINATION METER POWER SUPPLY AND GROUND CIRCUITS
Refer to MWI-30, "
COMBINATION METER : Diagnosis Procedure".
Are the inspection results normal?
YES >> GO TO 3.
NO >> Perform repairs as necessary.
3.CHECK HARNESS BETWEEN TR ANSFER CONTROL UNIT AND COMBINATION METER
1. Turn ignition switch OFF. (Stay for at least 5 seconds.)
2. Disconnect transfer control unit and combination meter harness connectors.
3. Check continuity between the following terminals.
- Transfer control unit harness connector E142 (A) terminal 5 and combination meter harness connector M23 (B) terminal 49.
Also check harness for short to ground and short to power.
Are the inspection results normal?
YES >> GO TO 4.
NO >> Repair or replace damaged parts.
4.CHECK INDICATOR LAMP CIRCUIT
1. Connect combination meter harness connector.
2. Turn ignition switch ON. (Do not start engine.)
3. Ground the following terminal using suitable wiring.
- Transfer control unit harness connector E142 terminal 5 and ground.
Does 4WD warning lamp turn on?
YES >> GO TO 5.
NO >> Replace combination meter. Refer to MWI-76,
"Removal and Installation".
5.SYMPTOM CHECK
Check again.
Are the inspection results normal?
YES >> Inspection End.
NO >> GO TO 6.
6.CHECK TRANSFER CONTROL UNIT
Check transfer control unit input/output signal. Refer to DLN-80, "
Reference Value".
Continuity should exist.
AWDIA0187ZZ
SDIA2774E
Revision: March 2010
2008 QX56

4WD SHIFT INDICATOR LAMP OR 4LO INDICATOR LAMP DO NOT CHANGE
DLN-105
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4WD SHIFT INDICATOR LAMP OR 4LO INDICATOR LAMP DO NOT
CHANGE
DescriptionINFOID:0000000001737187
4WD shift indicator lamp or 4LO indicator lamp do not change when switching the 4WD shift switch.
Diagnosis ProcedureINFOID:0000000001737188
1.CONFIRM THE SYMPTOM
Confirm 4WD shift indicator lamp and 4LO indicator lamp turn on when ignition switch is turned to ON.
Do 4WD shift indicator lamp and 4LO indicator lamp turn on?
YES >> GO TO 2.
NO >> Refer to DLN-101, "
Diagnosis Procedure".
2.CHECK SYSTEM FOR 4WD SHIFT SWITCH
Perform trouble diagnosis for 4WD shift switch system. Refer to DLN-31, "
Diagnosis Procedure".
Are the inspection results normal?
YES >> GO TO 3.
NO >> Repair or replace damaged parts.
3.CHECK SYSTEM FOR WAIT DETECTION SWITCH
Perform trouble diagnosis for wait detection switch system. Refer to DLN-35, "
Diagnosis Procedure".
Are the inspection results normal?
YES >> GO TO 4.
NO >> Repair or replace damaged parts.
4.CHECK SYSTEM FOR NEUTRAL-4LO SWITCH
Perform trouble diagnosis for neutral-4LO switch system. Refer to DLN-28, "
Diagnosis Procedure".
Are the inspection results normal?
YES >> GO TO 5.
NO >> Repair or replace damaged parts.
5.CHECK SYSTEM FOR ATP SWITCH
Perform trouble diagnosis for ATP switch system. Refer to DLN-114, "
Diagnosis Procedure".
Are the inspection results normal?
YES >> GO TO 6.
NO >> Repair or replace damaged parts.
6.CHECK SYSTEM FOR 2-4WD SOLENOID
Perform trouble diagnosis for 2-4W D solenoid system. Refer to DLN-57, "
Diagnosis Procedure".
Are the inspection results normal?
YES >> GO TO 7.
NO >> Repair or replace damaged parts.
7.CHECK SYSTEM FOR TRANSFER CONTROL DEVICE
Perform trouble diagnosis for transfer control device system. Refer to DLN-48, "
Diagnosis Procedure".
Are the inspection results normal?
YES >> GO TO 8.
NO >> Repair or replace damaged parts.
8.CHECK SYSTEM FOR ACTUATOR MOTOR
Perform trouble diagnosis for actuator motor system. Refer to DLN-39, "
Diagnosis Procedure".
Are the inspection results normal?
YES >> GO TO 9.
NO >> Repair or replace damaged parts.
Revision: March 2010 2008 QX56

ATP WARNING LAMP DOES NOT TURN ONDLN-107
< SYMPTOM DIAGNOSIS > [ATX14B]
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ATP WARNING LAMP DOES NOT TURN ON
DescriptionINFOID:0000000001737189
ATP warning lamp does not turn ON when the transfer case is switched in or out of 4LO with the A/T selector
lever in N position.
Diagnosis ProcedureINFOID:0000000001737190
1.CHECK SYSTEM FOR CAN COMMUNICATION LINE
Perform self-diagnosis. Refer to DLN-18, "
CONSULT-III Function (ALL MODE AWD/4WD)".
Do the self-diagnostic results indicate CAN communication?
YES >> Perform trouble diagnosis for CAN communication line.
NO >> GO TO 2.
2.CHECK SYSTEM FOR 4WD SHIFT SWITCH
Perform trouble diagnosis for 4WD shift switch system. Refer to DLN-31, "
Diagnosis Procedure".
Are the inspection results normal?
YES >> GO TO 3.
NO >> Repair or replace damaged parts.
3.CHECK SYSTEM FOR TRANSMIS SION RANGE SWITCH SIGNAL
Perform trouble diagnosis for transmission range switch signal system. Refer to DLN-38, "
Diagnosis Proce-
dure".
Are the inspection results normal?
YES >> GO TO 4.
NO >> Repair or replace damaged parts.
4.CHECK SYSTEM FOR ATP SWITCH
Perform trouble diagnosis for ATP switch system. Refer to DLN-114, "
Diagnosis Procedure".
Are the inspection results normal?
YES >> GO TO 5.
NO >> Repair or replace damaged parts.
5.CHECK HARNESS BETWEEN TR ANSFER CONTROL UNIT AND COMBINATION METER
1. Turn ignition switch OFF. (Stay for at least 5 seconds.)
2. Disconnect transfer control unit harness connector and combination meter harness connector.
3. Check continuity between the following terminals.
- Transfer control unit harness connector E142 (B) terminal 15 and combination meter harness connector M23 (A) terminal 43.
Continuity should exist.
AWDIA0185ZZ
Revision: March 2010 2008 QX56

DLN-108
< SYMPTOM DIAGNOSIS >[ATX14B]
ATP WARNING LAMP DOES NOT TURN ON
- Transfer control unit harness
connector E143 (B) terminal 40
and combination meter harness connector M23 (A) terminal 44.
Also check harness for short to ground and short to power.
Are the inspection results normal?
YES >> GO TO 6.
NO >> Repair or replace damaged parts.
6.CHECK ATP WARNING LAMP CIRCUIT
1. Place A/T selector lever in P position.
2. Connect combination meter harness connector and transfer control unit harness connector.
3. Disconnect ATP switch harness connector.
4. Ground the following terminal using suitable wiring.
- ATP switch harness connector F55 terminal 8 and ground.
5. Turn ignition switch ON. (Do not start engine.)
Does indicator lamp turn on?
YES >> GO TO 7.
NO >> Replace combination meter. Refer to MWI-76, "
Removal
and Installation".
7.SYMPTOM CHECK
Check again.
Are the inspection results normal?
YES >> Inspection End.
NO >> GO TO 8.
8.CHECK TRANSFER CONTROL UNIT
Check transfer control unit input/output signal. Refer to DLN-80, "
Reference Value".
Are the inspection results normal?
YES >> GO TO 9.
NO >> Check transfer control unit pin terminals fo r damage or loose connection with harness connector.
If any items are damaged, repair or replace damaged parts.
9.CHECK TRANSFER INNER PARTS
1. Disassemble transfer assembly. Refer to DLN-140, "
Disassembly and Assembly".
2. Check transfer inner parts.
Are the inspection results normal?
YES >> Inspection End.
NO >> Repair or replace damaged parts. 40 to 44: Continuity should not exist.
44 to 40: Continuity should exist.
AWDIA0186ZZ
SDIA2769E
Revision: March 2010
2008 QX56

DLN-110
< SYMPTOM DIAGNOSIS >[ATX14B]
4WD WARNING LAMP FLASHES RAPIDLY
4WD WARNING LAMP FLASHES RAPIDLY
DescriptionINFOID:0000000001737193
The 4WD warning lamp flashes quickly while driving (2 times / second). The lamp continues to flash until the
ignition switch is turned OFF.
Diagnosis ProcedureINFOID:0000000001737194
1.CHECK TIRE
Check the following.
• Tire pressure
• Wear condition
• Longitudinal tire size (There is no difference between longitudinal tires.)
Are the inspection results normal?
YES >> GO TO 2.
NO >> Repair or replace damaged parts.
2.CHECK 4WD WARNING LAMP
Stop the vehicle and allow it to idle for a short period of time.
Does flashing stop?
YES >> Inspection End.
NO >> GO TO 3.
3.CHECK TRANSFER FLUID TEMPERATURE
Perform trouble diagnosis for transfer fluid temperature system. Refer to DLN-67, "
Diagnosis Procedure".
Are the inspection results normal?
YES >> GO TO 4.
NO >> Repair or replace damaged parts.
4.SYMPTOM CHECK
Check again.
Are the inspection results normal?
YES >> Inspection End.
NO >> GO TO 5.
5.CHECK TRANSFER CONTROL UNIT
Check transfer control unit input/output signal. Refer to DLN-80, "
Reference Value".
Are the inspection results normal?
YES >> Inspection End.
NO >> Check transfer control unit pin terminals fo r damage or loose connection with harness connector.
If any items are damaged, repair or replace damaged parts.
Revision: March 2010 2008 QX56