Inspection Procedure 44: A/T-ECU power supply system

SYMPTOMS

A/T-ECU cannot be turned ON.

PROBABLE CAUSES

Damaged wiring harness and connectors
Malfunction of A/T-ECU

DIAGNOSIS PROCEDURE

STEP 1. Check for short circuit, and open circuit in BAT line between the fusible link (5) and the A/T-ECU connector.

Q. Is the check result normal?

	Go to Step 2.

	Repair the connector(s) or wiring harness.

STEP 2. Check for short circuit, and open circuit in IGSW line between the IG1 relay connector and the A/T-ECU connector.

Q. Is the check result normal?

	Go to Step 3.

	Repair the connector(s) or wiring harness.

STEP 3. Check for open circuit in GRP1 line between the A/T-ECU connector and earth.

Q. Is the check result normal?

	Go to Step 4.

	Repair the connector(s) or wiring harness.

STEP 4. Retest the system.

Recheck the trouble symptom.

Q. Does the malfunction take place again?

	Replace A/T-ECU.

	Intermittent malfunction (Refer to GROUP 00 - How to Cope with Intermittent Malfunction )..