TCM Power Source Circuit

AA80E AUTOMATIC TRANSMISSION: AUTOMATIC TRANSMISSION SYSTEM: TCM Power Source Circuit
- TCM Power Source Circuit

DESCRIPTION

When the engine switch is turned on (IG), voltage from the ECM's MREL terminal is applied to the EFI MAIN 2 relay. This causes the contacts of the EFI MAIN 2 relay to close, which supplies power to terminal +B of the TCM.

WIRING DIAGRAM







PROCEDURE

1. CHECK HARNESS AND CONNECTOR (TCM - BODY GROUND)

(a) Disconnect the TCM connectors.





(b) Turn the engine switch off.

(c) Measure the resistance of the wire harness side connector.

Standard resistance:





NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- Continue to next step.

2. CHECK TCM (BATTERY - TCM)

(a) Disconnect the TCM connectors.





(b) Turn the engine switch on (IG).

(c) Measure the voltage of the wire harness side connectors.

Standard voltage:





NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR

OK -- GO TO ECM POWER SOURCE CIRCUIT (ENGINE CONTROL SYSTEM / SFI SYSTEM) ECM Power Source Circuit