Main Power Supply and Ground Circuit Testing
TROUBLE DIAGNOSIS FOR POWER SUPPLYAT-MAIN-01:
Wiring Diagram-AT-MAIN
TCM TERMINALS AND REFERENCE VALUE
Remarks: Specification data are reference values.
Diagnostic Procedure
1. CHECK TCM POWER SOURCE
1. Turn ignition switch to ON position. (Do not start engine.)
2. Check voltage between TCM harness connectors M77, M78 terminals (10, 19, 28) and ground.
Voltage: Battery voltage
3. Turn ignition switch to OFF position.
4. Check voltage between TCM harness connector M78 terminal 28 and ground.
Voltage: Battery voltage
OK or NG
OK >> GO TO 2.
NG >> Check the following items:
^ Harness for open or short between fuse block J/B harness connectors M26, M27 and TCM harness connectors M77, M78
^ Ignition switch and fuse.
2. CHECK TCM GROUND CIRCUIT
1. Turn ignition switch to OFF position.
2. Disconnect TCM harness connector.
3. Check continuity between TCM harness connector M78 terminals (25, 48) and ground.
Continuity should exist.
If OK, check harness for short to ground and short to power.
OK or NG
OK >> INSPECTION END.
NG >> Repair open circuit or short to ground or short to power in harness or connectors.