2004 INFINITI QX56 check engine

TROUBLE DIAGNOSES FOR SYMPTOMS
TF-85
C
E
F
G
H
I
J
K
L
MA
B
TF
Revision: August 20072004 QX56
TROUBLE DIAGNOSES FOR SYMPTOMSPFP:00007
Symptom 1. 4WD Shift Indicator Lamp Does Not Turn ON (Although the ignition
switch is turned ON, all the 4WD indicator lamps do not turn ON for 1 second)
EDS0018E
1. CHECK TRANSFER CONTROL UNIT POWER SOURCE
1. Turn ignition switch to OFF position and disconnect transfer control unit harness connector E142.
2. Turn ignition switch to ON position. (Do not start engine.)
3. Check voltage between transfer control unit harness connector
E142 terminals 16 (Y/R), 22 (Y/R) and ground.
OK or NG
OK >> GO TO 2.
NG >> Check the following.

Continuity between ignition switch and transfer control unit

Ignition switch and No. 49 fuse (10A)
WDIA0071E
WDIA0079E
Voltage : Battery voltage
LDIA0086E

TROUBLE DIAGNOSES FOR SYMPTOMS
TF-87
C
E
F
G
H
I
J
K
L
MA
B
TF
Revision: August 20072004 QX56
Symptom 2. 4WD Warning Lamp Does Not Turn ON (Although the ignition
switch is turned ON, the 4WD warning lamp does not turn ON)
EDS0018F
1. CHECK TRANSFER CONTROL UNIT POWER SOURCE
1. Turn ignition switch to OFF position and disconnect transfer control unit harness connector E142.
2. Turn ignition switch to ON position (do not start engine).
3. Check voltage between transfer control unit harness connector
E142 terminals 16 (Y/R), 22 (Y/R) and ground.
OK or NG
OK >> GO TO 2.
NG >> Check the following.

Continuity between ignition switch and transfer con-
trol unit

Ignition switch and No. 49 fuse (10A)
2. CHECK TRANSFER CONTROL UNIT GROUND CIRCUIT
1. Turn ignition switch to OFF position.
2. Disconnect transfer control unit harness connectors E142 and
E143.
3. Measure resistance between transfer control unit harness con-
nectors E142 and E143 terminals 3 (B), 6 (B), 45 (B) and
ground.
OK or NG
OK >> GO TO 3.
NG >> Check continuity between transfer control unit and
ground.
3. CHECK 4WD WARNING LAMP CIRCUIT AND COMBINATION METER
Check the following.

Combination meter. Refer to DI-17, "How to Proceed With Trouble Diagnosis" .

Continuity between ignition switch and combination meter

Continuity between combination meter and transfer control unit
OK or NG
OK >> Replace transfer control unit. Refer to TF-98, "Removal and Installation" .
NG >>

Repair or replace harness or connector.

Replace combination meter. Refer to DI-25, "Removal and Installation of Combination Meter" .
WDIA0080E
Voltage : Battery voltage
LDIA0089E
Resistance : Continuity should exist.
LDIA0087E

TF-90
TROUBLE DIAGNOSES FOR SYMPTOMS
Revision: August 20072004 QX56
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)
EDS0018I
1. CHECK TRANSFER CONTROL UNIT POWER SUPPLY CIRCUIT
1. Disconnect battery negative terminal, then transfer control unit connectors.
2. Connect battery negative terminal and turn ignition switch ON (with engine stopped).
3. Check voltage across transfer control unit connector E142 and E143 terminals 16 (Y/R), 47 (W) and
ground.
OK or NG
OK >> GO TO 2.
NG >> Check the following.

Continuity between battery, ignition switch and trans-
fer control unit

Ignition switch. Refer to PG-4, "POWER SUPPLY
ROUTING CIRCUIT" .

No. 53 fuse (20A) and No. 49 fuse (10A)
2. CHECK TRANSFER CONTROL UNIT GROUND CIRCUIT
1. Turn ignition switch to OFF position.
2. Disconnect transfer control unit harness connectors E142 and
E143.
3. Measure resistance between transfer control unit harness con-
nectors E142 and E143 terminals 3 (B), 6 (B), 45 (B) and
ground.
OK or NG
OK >> GO TO 3.
NG >> Check continuity between transfer control unit and
ground. Voltage : Battery voltage
WDIA0071E
WDIA0081E
Resistance : Continuity should exist.
LDIA0087E

TF-108
TRANSFER OIL FILTER
Revision: August 20072004 QX56
3. Apply ATF to the two new O-rings (1), and install them on the oil
filter (2).
CAUTION:
Do not reuse O-rings.
4. Install the oil filter to the transfer assembly. Tighten the bolts to
the specified torque. Refer to TF-110, "
Transfer Components" .
CAUTION:

Do not damage oil filter.

Attach oil filter and tighten bolts evenly.
5. Check the transfer fluid. Refer to MA-24, "
Checking Transfer
Fluid" .
6. Start the engine for one minute. Then stop the engine and
recheck the transfer fluid.
WDIA0285E
SDIA2136E