2004 INFINITI QX56 4WD

TROUBLE DIAGNOSIS — BASIC INSPECTION
TF-51
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Revision: August 20072004 QX56
5. CHECK 4WD SHIFT INDICATOR LAMP
1. Move A/T selector lever to P position.
2. Set 4WD shift switch from 4H to 4LO.
3. While shifting from 4H to 4LO, does 4WD shift indicator lamp
turn OFF and ATP warning lamp turn ON?
Ye s o r N o
Yes >> GO TO 6.
No >> Go to Symptoms 3 and 4. Refer to TF-88, "
Symptom 3.
4WD Shift Indicator Lamp Does Not Turn OFF (When
4WD shift switch is set from 4H to 4LO, all the 4WD shift
indicator lamps do not turn off)" and TF-89, "Symptom
4. ATP Warning Lamp Does Not Turn ON (When 4WD
shift switch is set from 4H to 4LO with the A/T selector
lever in P position, the ATP warning lamp does not turn
on)" .
6. CHECK 4WD SHIFT INDICATOR LAMP
Do the 4WD shift indicator lamps indicate 4LO when the 4WD shift
switch is set in 4LO?
Ye s o r N o
Yes >> GO TO 7.
No >> Go to Symptom 5. Refer to TF-90, "
Symptom 5. 4LO Indicator Lamp Does Not Turn ON (When
4WD shift switch is set from 4H to 4LO position, 4LO indicator lamp does not turn ON)" .
LDIA0061E
WDIA0071E
LDIA0061E
WDIA0071E

TF-52
TROUBLE DIAGNOSIS — BASIC INSPECTION
Revision: August 20072004 QX56
7. CHECK 4WD SHIFT INDICATOR LAMP (*1)
1. Set 4WD shift switch from 4LO to 4H.
2. Does 4LO indicator lamp flicker? (*1)
*1: While “Wait” function is operating, 4LO indicator lamp flashes.
Ye s o r N o
Yes >> Go to Symptoms 6 and 7. Refer to TF-91, "Symptom 6. 4WD Shift Indicator Lamp Does Not Indi-
cate “LOCK” (When 4WD shift switch is set to “4H”, 4WD shift indicator lamp does not indicate
“LOCK”)" and TF-92, "Symptom 7. 4WD Shift Indicator Lamp Repeats Flickering (4WD Shift Indi-
cator Lamp Keeps Flickering)" .
No >> Go to “3. CRUISE TEST”. Refer to TF-53, "
3. CRUISE TEST" .

TROUBLE DIAGNOSIS — BASIC INSPECTION
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Revision: August 20072004 QX56
3. CRUISE TEST
1. INSPECTION START
Do you have CONSULT-II?
Ye s o r N o
Yes >> GO TO 2.
No >> GO TO 3.
2. CHECK INPUT SIGNAL
With CONSULT-II
1. Warm up engine to normal operating temperature.
2. Park vehicle on flat surface.
3. Set 4WD shift switch to 4H position.
4. Set 4WD shift switch to AUTOposition.
5. Start engine.
6. Drive for at least 30 seconds at a speed higher than 20 km/h (12 MPH).
(Drive vehicle until “FLUID TEMP SE” exceeds 0.9V.)
7. Park vehicle on flat surface.
8. Set 4WD shift switch to 2WD position.
9. Leave vehicle for at least 80 seconds with “FLUID TEMP SE” at
0.9V or less.
10. Is 4WD warning lamp turned ON?
Ye s o r N o
Yes >> Perform self-diagnosis. Refer to TF-31, "Trouble Diag-
nosis with CONSULT-II" .
No >> GO TO 4.
3. CHECK INPUT SIGNAL
Without CONSULT-II
1. Warm up engine to normal operating temperature.
2. Park vehicle on flat surface.
3. Set 4WD shift switch to 4H position.
4. Set 4WD shift switch to AUTO position.
5. Start engine.
6. Drive vehicle for at least 30 seconds at a speed higher than 20 km/h (12 MPH).
7. Park vehicle on flat surface.
8. Set 4WD shift switch to 2WD position.
9. Is 4WD warning lamp turned ON?
Ye s o r N o
Yes >> Perform self-diagnosis. Refer to TF-27, "Trouble Diagnosis without CONSULT-II" .
No >> GO TO 4.
SMT972D

TF-54
TROUBLE DIAGNOSIS — BASIC INSPECTION
Revision: August 20072004 QX56
4. (1) CHECK TIGHT CORNER BRAKING SYMPTOM
1. Set 4WD shift switch to AUTO position.
2. Drive vehicle at speed lower than 20 km/h (12 MPH) with steering wheel fully turned.
3. Does tight corner braking symptom occur?
Ye s o r N o
Yes >> GO TO 5.
No >> GO TO 6.
5. CONFIRM SYMPTOM AGAIN
Confirm symptom and self-diagnosis again.
Refer to TF-27, "
Trouble Diagnosis without CONSULT-II" and TF-31, "Trouble Diagnosis with CONSULT-II" .
OK or NG
OK >> GO TO 6.
NG >> Go to Symptoms 8 and 9. Refer to TF-93, "
Symptom 8. Tight Corner Braking Symptom (Tight Cor-
ner Braking Symptom Occurs-Hydraulic System Failure)" and TF-94, "Symptom 9. 4WD System
Does Not Operate (The Vehicle Cannot Be Put Into 4WD Mode-Hydraulic System Failure)" .
6. (2) CHECK TIGHT CORNER BRAKING SYMPTOM
1. Set 4WD shift switch to 4H position.
2. Drive vehicle at speed lower than 20 km/h (12 MPH) with steering wheel fully turned.
3. Does tight corner braking symptom occur?
Ye s o r N o
Yes >> Inspection End.
No >> GO TO 7.
7. CONFIRM SYMPTOM AGAIN
Confirm symptom and self-diagnosis again.
Refer to TF-27, "
Trouble Diagnosis without CONSULT-II" and TF-31, "Trouble Diagnosis with CONSULT-II" .
OK or NG
OK >> Inspection End.
NG >> Go to Symptoms 8 and 9. Refer to TF-93, "
Symptom 8. Tight Corner Braking Symptom (Tight Cor-
ner Braking Symptom Occurs-Hydraulic System Failure)" and TF-94, "Symptom 9. 4WD System
Does Not Operate (The Vehicle Cannot Be Put Into 4WD Mode-Hydraulic System Failure)" .

TROUBLE DIAGNOSIS — GENERAL DESCRIPTION
TF-55
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Revision: August 20072004 QX56
TROUBLE DIAGNOSIS — GENERAL DESCRIPTIONPFP:00000
Transfer Control Unit Terminals and Reference ValueEDS00181
TRANSFER CONTROL UNIT HARNESS CONNECTOR LAYOUT
TRANSFER CONTROL UNIT INSPECTION TABLE
LDIA0066E
Te r m i n a l
No.Item ConditionJudgement standard
(Approx.)
12-4WD shift solenoid
valve &4WD shift switch is set to 2WD posi-
tion.Less than 1V
4WD shift switch is set to any posi-
tion other than 2WD.Battery voltage
24WD shift indicator lamp
(2WD)Lamp lights while system is operating
properly.Less than 1V
&2WD indicator lamp does not come
on.Battery voltage
3Ground — —
4 Transfer shift relay (High)While actuator is operating (4H →
4LO)Battery voltage
Actuator does not operate. Less than 1V
5 4WD warning lampLamp comes ON (when engine is
stopped).
(Fail-safe condition appears on dis-
play, engine is stopped, actuator
position detection switch is inopera-
tive, oil temperature is too high and/
or tires of different size are installed.)Less than 1V
Except above Battery voltage
6Ground — — —
7CAN-H — — —
8CAN-L — — —
9 4WD shift switch (2WD)
&4WD shift switch is set to 2WD posi-
tion.Battery voltage
4WD shift switch is set to any posi-
tion other than 2WD.Less than 1V
10 Transfer dropping resistor4WD shift switch is set to AUTO posi-
tion.4 - 14V
4WD shift switch is set to any posi-
tion other than 2WD.Less than 1V

TF-56
TROUBLE DIAGNOSIS — GENERAL DESCRIPTION
Revision: August 20072004 QX56
114WD shift indicator lamp
(4H)“4H” indicator lamp comes ON. Less than 1V
4WD shift switch is set to any posi-
tion other than 4H.Battery voltage
124WD shift indicator lamp
(4LO)“4LO” indicator lamp comes ON. 0V
4WD shift switch is set to any posi-
tion other than 4LO.Battery voltage
13 Transfer shift relay (Low)
&While actuator is operating (4LO →
4H)Battery voltage
Actuator does not operate. 0V
14 Transfer motor relayTransfer motor relay is ON. Battery voltage
Transfer motor relay is OFF. Less than 1V
15 ATP lampAT selector lever is set to P position. Battery voltage
AT selector lever is set to any posi-
tion other than P.0V
16 Power supply —Ignition key is set to ON position. Battery voltage
Ignition key is set to OFF position. 0V
18 4WD shift switch (4H)
&4WD shift switch is set to 4H posi-
tion.Battery voltage
4WD shift switch is set to any posi-
tion other than 4H.Less than 1V
19 4WD solenoid valve4WD shift switch is set to AUTO posi-
tion.1.5 - 3V
4WD shift switch is set to any posi-
tion other than 2WD.Less than 1V
214WD shift indicator lamp
(AUTO)“AUTO” indicator lamp comes ON. 0V
4WD shift switch is set to any posi-
tion other than AUTO.Battery voltage
22 Power supply —Ignition key is set to ON position. Battery voltage
Ignition key is set to OFF position. 0V
23 4WD shift switch (4LO)
&4WD shift switch is set to 4LO posi-
tion.Battery voltage
4WD shift switch is set to any posi-
tion other than 4LO.Less than 1V
24 4WD shift switch (AUTO)4WD shift switch is set to AUTO posi-
tion.Battery voltage
4WD shift switch is set to any posi-
tion other than AUTO.Less than 1V
25 Neutral-4LO switchTransfer is set to 4LO position. 0V
Transfer is set to any position other
than 4LO.Battery voltage
27Transfer 4H actuator
switch4WD shift switch is set to 4H posi-
tion.Less than 1V
4WD shift switch is set to any posi-
tion other than 4H.Battery voltage
28 Sensor ground — Less than 1V Te r m i n a l
No.Item ConditionJudgement standard
(Approx.)

TROUBLE DIAGNOSIS — GENERAL DESCRIPTION
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Revision: August 20072004 QX56
30Power supply for A/D
converter &Ignition key is set to ON position. 4.5 - 5.5V
Ignition key is set to OFF position. 0V
31Transfer fluid tempera-
ture sensor &At 20°C (68°F) 1.1V
At 80°C (176°F) 0.3V
33 Transfer shift relay (High)
&While actuator is operating from “4H”
to “4LO”Battery voltage
Actuator does not operate. 0V
34 Clutch pressure switch4WD shift switch is set to AUTO or
4H, then A/T selector lever is set to D
position. (wait detection system:
OFF)Battery voltage
4WD shift switch is set to 2WD,
AUTO or 4H, then A/T selector lever
is set to D position. (wait detection
system: ON)0V
35 Line pressure switch4WD shift switch is set to 2WD,
AUTO or 4H, then A/T selector lever
is set to D position.Battery voltage
—0V
36 CONSULT-II (RX) — — —
40 ATP switch
&A/T selector lever is set to P position. Battery voltage
A/T selector lever is set to any posi-
tion other than P.Less than 1V
41Transfer motor relay
monitorTransfer motor relay is ON. Battery voltage
Transfer motor relay is OFF. Less than 1V
42Transfer shift relay
(LOW)While actuator is operating from
“4LO” to “4H” positionBattery voltage
Actuator does not operate. 0V
43 Wait detection switch4WD shift switch is set to any posi-
tion other than 4LO.Battery voltage
4WD shift switch is set to 4LO posi-
tion.*3Less than 1V
44Transfer 4LO actuator
switch4WD shift switch is set to any posi-
tion other than 4LO. (Actuator: High
position)Battery voltage
4WD shift switch is set to 4LO posi-
tion. (Actuator: Low position)Less than 1V
45 Ground — — — Te r m i n a l
No.Item ConditionJudgement standard
(Approx.)

TF-60
4WD SOLENOID VALVE
Revision: August 20072004 QX56
4WD SOLENOID VALVEPFP:00000
Diagnostic ProcedureEDS00183
1. CHECK 4WD SOLENOID VALVE
Refer to TF-95, "
4WD SOLENOID VALVE, CLUTCH PRESSURE
SWITCH AND LINE PRESSURE SWITCH" .
OK or NG
OK >> GO TO 2.
NG >> Repair or replace 4WD solenoid valve.
2. CHECK POWER SOURCE CIRCUIT
1. Turn ignition switch to OFF position.
2. Disconnect transfer control unit harness connector E142.
3. Check resistance between transfer terminal cord assembly har-
ness connector F56 terminal 6 (L) and transfer control unit har-
ness connector E142 terminal 10 (L/W).
OK or NG
OK >> GO TO 3.
NG >> Check the following.

Transfer dropping resistor
Refer to TF-96, "
TRANSFER DROPPING RESISTOR" .

Continuity between transfer terminal cord assembly harness connector F56 terminal 6 (L) and
transfer dropping resistor harness connector E135 terminal 2 (L).

Continuity between transfer dropping resistor harness connector E135 terminal 1 (L/W) and
transfer control unit harness connector E142 terminal 10 (L/W).
3. CHECK POWER SOURCE CIRCUIT
1. Turn ignition switch to OFF position.
2. Check continuity between transfer terminal cord assembly har-
ness connector F56 terminal 6 (L) and transfer control unit har-
ness connector E142 terminal 19 (L).
Continuity should exist.
OK or NG
OK >> GO TO 4.
NG >> Repair or replace harness between transfer terminal
cord assembly harness connector F56 terminal 6 (L)
and transfer control unit harness connector E142 termi-
nal 19 (L).
SMT775D
Resistance : 11.2 - 12.8Ω
LDIA0067E
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