Diagnostic Procedure

WARNING: This page is about a different car, the 2007 Nissan Pathfinder. However, it is still accessible from the selected car via links, so may be relevant.

CHECK TRANSFER CONTROL UNIT POWER SUPPLY CIRCUIT

Turn ignition switch "OFF". (Stay for at least 5 seconds.)
Disconnect transfer control unit harness connector.

Check voltage between transfer control unit harness connector terminals and ground.

CONNECTOR TERMINAL VOLTAGE REFERENCE

Connector	Terminal	Voltage (Approx.)
M152	19 - Ground	Battery voltage
M152	25 - Ground	0V
M153	40 - Ground	Battery voltage
	44 - Ground	0V
	45 - Ground	0V

Fig 1: Checking Voltage Between Transfer Control Unit Connector Terminals And Ground

Turn ignition switch "ON". (Do not start engine.)

Check voltage between transfer control unit harness connector terminals and ground.

CONNECTOR TERMINAL VOLTAGE REFERENCE

Connector	Terminal	Voltage (Approx.)
M152	19 - Ground	Battery voltage
M152	25 - Ground
M153	40 - Ground
	44 - Ground
	45 - Ground

Fig 2: Checking Voltage Between Transfer Control Unit Connector Terminals And Ground

OK or NG

OK: GO TO 2.

NG: Check the following. If any items are damaged, repair or replace damaged parts.

40A fusible link (No. j located in the fuse and fusible link box). Refer to "POWER SUPPLY ROUTING CIRCUIT ".
10A fuses [No. 21 located in the fuse block-junction block (J/B) and 57 and 58 located in the fuse and relay box]. Refer to "POWER SUPPLY ROUTING CIRCUIT ".
Harness for short or open between battery and transfer control unit harness connector M152 terminal 19.
Harness for short or open between battery and transfer shut off relay 2 harness connector E157 terminal 1 and 3.
Harness for short or open between battery and transfer shut off relay 1 harness connector E156 terminal 3.
Harness for short or open between ignition switch and transfer control unit harness connector M152 terminal 25.
Harness for short or open between ignition switch and transfer shut off relay 1 harness connector E156 terminal 1.
Harness for short or open transfer shut off relay 2 harness connector E157 terminal 5 and transfer control unit harness connector M153 terminals 44, 45.
Harness for short or open between transfer shut off relay 1 harness connector E156 terminal 5 and transfer control unit harness connector M153 terminals 44, 45.
Harness for short or open between transfer shut off relay 2 harness connector E157 terminal 2 and transfer control unit harness connector M153 terminal 40.
Harness for open between transfer shut off relay 1 harness connector E156 terminal 2 and ground.
Battery and ignition switch. Refer to "POWER SUPPLY ROUTING CIRCUIT ".
Transfer shut off relay 1, 2. Refer to "COMPONENT INSPECTION ".

CHECK TRANSFER CONTROL UNIT GROUND CIRCUIT
1. Turn ignition switch "OFF". (Stay for at least 5 seconds.)
2. Disconnect transfer control unit harness connector.
3. Check continuity between transfer control unit harness connector M152 terminals 6, 18, M153 terminal 32 and ground.
  Continuity should exist.
  
  Fig 3: Checking Continuity Between Transfer Control Unit Harness Connector M152 Terminals 6, 18, M153 Terminal 32 And Ground
  
  Also check harness for short to power.
OK or NG

OK: GO TO 3.

NG:
- Repair open circuit or short to power in harness or connectors.
- Harness for short or open between transfer shut off relay harness connector E157 terminal 2 and transfer control unit harness connector terminal 40.

CHECK COMBINATION METER POWER SUPPLY CIRCUIT

Turn ignition switch "OFF". (Stay for at least 5 seconds.)
Disconnect combination meter harness connector.

Check voltage between combination meter harness connector terminals and ground.

CONNECTOR TERMINAL VOLTAGE REFERENCE

Connector	Terminal	Voltage (Approx.)
M24	16 - Ground	0V

Fig 4: Checking Voltage Between Combination Meter Harness Connector Terminals And Ground

Turn ignition switch "ON". (Do not start engine.)

Check voltage between combination meter harness connector terminals and ground.

CONNECTOR TERMINAL VOLTAGE REFERENCE

Connector	Terminal	Voltage (Approx.)
M24	16 - Ground	Battery voltage

Fig 5: Checking Voltage Between Combination Meter Connector M24 Terminal 16 And Ground

OK or NG

OK: GO TO 4.

NG: Check the following. If any items are damaged, repair or replace damaged parts.

10A fuse [No. 14, located in the fuse block (J/B)] or ignition switch.
Harness for short or open between ignition switch and combination meter harness connector terminal 16

CHECK HARNESS BETWEEN TRANSFER CONTROL UNIT AND COMBINATION METER
1. Turn ignition switch "OFF". (Stay for at least 5 seconds.)
2. Check continuity between transfer control unit harness connector M153 terminal 38 and combination meter harness connector M24 terminal 28.
  Continuity should exist.
  
  Fig 6: Checking Continuity Between Transfer Control Unit Connector Terminal And Combination Meter Connector Terminal
  
  Also check harness for short to ground and short to power.
OK or NG

OK: GO TO 5.

NG: Repair or replace damaged parts.
CHECK INDICATOR LAMP CIRCUIT
1. Turn ignition switch "OFF". (Stay for at least 5 seconds.)
2. Connect combination meter harness connector.
3. Disconnect transfer control unit harness connector.
4. Turn ignition switch "ON". (Do not start engine.)
5. Ground the following terminal using suitable wiring.
  - Transfer control unit harness connector M153 terminal 38 and ground.
Does the indicator lamp turn on?

OK: GO TO 6.

NG: Replace the combination meter. Refer to "COMBINATION METER ".
SYMPTOM CHECK
Check again.

OK or NG

OK: Inspection End.

NG: GO TO 7.
CHECK TRANSFER CONTROL UNIT
Check transfer control unit input/output signal. Refer to "TRANSFER CONTROL UNIT INPUT/OUTPUT SIGNAL REFERENCE VALUES ".

OK or NG

OK: Inspection End.

NG: Check transfer control unit pin terminals for damage or loose connection with harness connector. If any items are damaged, repair or replace damaged parts.