Power Supply Circuit For Transfer Control Unit

Power Supply Circuit For Transfer Control Unit

CONSULT-II REFERENCE VALUE IN DATA MONITOR MODE:

TRANSFER CONTROL UNIT TERMINALS AND REFERENCE VALUE:

CAUTION: When using a circuit tester to measure voltage for inspection, be sure not to extend forcibly any connector terminals.

DIAGNOSTIC PROCEDURE

1. CHECK POWER SUPPLY
1. Turn ignition switch "OFF". (Stay for at least 5 seconds.)
2. Connect transfer control unit harness connector.








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








4. Turn ignition switch "ON". (Do not start engine.)
5. Check voltage between transfer control unit harness 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.
^ 10A fuses No. 26 located in fuse and fusible link box and No. 59 located in the fuse and relay box. Refer to PG-4, "POWER SUPPLY ROUTING CIRCUIT". Power Supply Routing Circuit Schematic
^ 20A fuse No. 53 located in the IPDM E/R. Refer to PG-4, "POWER SUPPLY ROUTING CIRCUIT". Power Supply Routing Circuit Schematic
^ Harness for short or open between battery and transfer control unit harness connector terminals 47.
^ Harness for short or open between battery and transfer control unit harness connector terminal 29.
^ Harness for short or open between battery and transfer shut off relay harness connector E69 terminal 1, and 3.
^ Harness for short or open between transfer shut off relay harness connector E69 terminal 2 and transfer control unit harness connector terminal 30.
^ Harness for short or open between transfer shut off relay harness connector E69 terminal 5 and transfer control unit harness connector terminals 16 and 22.
^ Battery and ignition switch. Refer to PG-4, "POWER SUPPLY ROUTING CIRCUIT". Power Supply Routing Circuit Schematic
^ Transfer shut off relay. Refer to, "COMPONENT INSPECTION".

2. CHECK 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 E142 terminals 3, 6, E143 terminal 45 and ground.
Continuity should exist.
Also check harness for short to ground and short to power.
OK or NG
OK >> GO TO 3.
NG >> Repair open circuit or short to ground or short to power in harness or connectors.

3. CHECK TRANSFER CONTROL UNIT
Check transfer control unit input/output signal. Refer to TF-35, "Transfer Control Unit Input/Output Signal Reference Values". Pinout Values and Diagnostic Parameters
OK or NG
OK >> GO TO 4.
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.

4. CHECK DTC
Perform the self-diagnosis, after driving a vehicle for a while.
OK or NG
OK >> Inspection End.
NG >> Replace transfer control unit.

COMPONENT INSPECTION
1. Turn ignition switch "OFF". (Stay for at least 5 seconds.)
2. Remove transfer shut off relay.








3. Apply 12V direct current between transfer shut off relay terminals 1 and 2.
4. Check continuity between relay terminals 3 and 5.
5. If NG, replace the transfer shut off relay.