4WD Warning Lamp Does Not Turn On
4WD Warning Lamp Does Not Turn ONSYMPTOM: 4WD warning lamp does not turn ON when turning ignition switch to "ON".
DIAGNOSTIC PROCEDURE
1. CHECK POWER SUPPLY
1. Turn ignition switch "OFF". (Stay for at least 5 seconds.)
2. Disconnect 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 the fuse and fusible link box or 59 located in the fuse and relay box]
^ 20A fuse (No. 53, located in the IPDM E/R)
^ Harness for short or open between battery and transfer control unit harness connector E142 terminal 19.
^ Harness for short or open between battery and transfer shut off relay 2 harness connector E47 terminal 1 and 5.
^ Harness for short or open between battery and transfer shut off relay 1 harness connector E46 terminal 5.
^ Harness for short or open between ignition switch and transfer control unit harness connector E142 terminal 25.
^ Harness for short or open between ignition switch and transfer shut off relay 1 harness connector E46 terminal 2.
^ Harness for short or open between transfer shut off relay 2 harness connector E47 terminal 3 and transfer control unit harness connector E143 terminals 44, 45.
^ Harness for short or open between transfer shut off relay 1 harness connector E46 terminal 3 and transfer control unit harness connector E143 terminals 44, 45.
^ Harness for short or open between transfer shut off relay 2 harness connector E47 terminal 2 and transfer control unit harness connector E143 terminal 40.
^ Harness for open between transfer shut off relay 1 harness connector E46 terminal 1 and ground.
^ Battery and ignition switch. Refer to PG-4, "POWER SUPPLY ROUTING CIRCUIT". Power Supply Routing Circuit Schematic
^ Transfer shut off relay 1, 2. Refer to TF-43, "COMPONENT INSPECTION". Power Supply Circuit For Transfer Control Unit
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 6 and 18, and E143 terminal 32 and ground.
Continuity should exist.
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.
3. CHECK COMBINATION METER POWER SUPPLY CIRCUIT
1. Turn ignition switch "OFF". (Stay for at least 5 seconds.)
2. Disconnect combination meter harness connector.
3. Check voltage between combination meter harness connector terminals and ground.
4. Turn ignition switch "ON". (Do not start engine.)
5. Check voltage between combination meter harness connector terminals 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 24
4. 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 E143 terminal 38 and combination meter harness connector M24 terminal 34.
Continuity should exist.
Also check harness for short to ground and short to power.
OK or NG
OK >> GO TO 5.
NG >> Repair or replace damaged parts.
5. CHECK 4WD WARNING LAMP CIRCUIT
1. Turn ignition switch "OFF". (Stay for at least 5 seconds.)
2. Check the combination meter. Refer to DI-7, "Arrangement of Combination Meter". Connector Locations
OK or NG
OK >> GO TO 6.
NG >> Replace the combination meter.
6. SYMPTOM CHECK
Check again.
OK or NG
OK >> Inspection End.
NG >> GO TO 7.
7. CHECK TRANSFER CONTROL UNIT
Check transfer control unit input/output signal. Refer to TF-29, "Transfer Control Unit Input/Output Signal Reference Values". Pinout Values and Diagnostic Parameters
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.