Inspection Procedure 26

INSPECTION PROCEDURE 26: Generator Output Voltage is Low (Approximately 12.3 Volts)

Generator Circuit Part 1:

Generator Circuit Part 2:

CIRCUIT OPERATION
- The ECM controls generator output current by duty-controlling continuity between the generator G terminal (terminal 1) and ground.

TROUBLESHOOTING HINTS (The most likely causes for this charging system:)
- Malfunction of the charging system.
- Short circuit in the harness between generator G terminal and ECM.
- ECM failed.

DIAGNOSIS

STEP 1. Measure the voltage at generator intermediate connector B-14 by backprobing.




1. Do not disconnect the connector B-14.
2. Start the engine and run at idle.




3. Measure the voltage between terminal No. 10 and ground by backprobing.
a. Engine: warming up
b. Radiator fan: stopped
c. Headlight switch: OFF to ON
d. Rear defogger switch: OFF to ON
e. Stoplight switch: OFF to ON
- Voltage rises by 0.2 - 3.5 volts.

4. Turn the ignition switch to the "LOCK" (OFF) position.

Q: Is the measured voltage between 0.2 and 3.5 volts?

YES: Replace the generator. Then confirm that the malfunction symptom is eliminated.

NO: Go to Step 2.




STEP 2. Check connector B-14 at generator intermediate connector for damage.

Q: Is the connector in good condition?

YES: Go to Step 3.

NO: Repair or replace it. Then confirm that the malfunction symptom is eliminated.




STEP 3. Check connector B-25 at generator connector for damage.

Q: Is the connector in good condition?

YES: Go to Step 4

NO: Repair or replace it. Then confirm that the malfunction symptom is eliminated.




STEP 4. Check connector C-121 at ECM for damage. Q:Is the connector in good condition?

YES: Go to Step 5.

NO: Repair or replace it. Then confirm that the malfunction symptom is eliminated.







STEP 5. Check for open circuit and short circuit to ground and harness damage between generator connector B-25 (terminal No. 1) and ECM connector C-121 (terminal No. 8).

NOTE: Check harness after checking intermediate connector B-14. If intermediate connector is damaged, repair or replace it. The confirm that the malfunction symptom is eliminated.

Q: Is the harness wire in good condition?

YES: Replace the ECM. Then confirm that the malfunction symptom is eliminated.

NO: Repair it. Then confirm that the malfunction symptom is eliminated.