STEP 1. Measure the voltage at ECM connector by using power plant ECU check harness special tool MB992110.
(1) Disconnect all ECM connectors. Connect the power plant ECU check harness special tool MB992110 between the separated connectors.
(2) Start the engine and run at idle.
(3) Measure the voltage between terminal ALTG and ground.note | Vehicle for Canada, the headlight, taillight, etc. remain lit even when the lighting switch is in "OFF" position but this is no problem for checks. |
- Engine: warming up, idling
- Radiator fan: stopped
- Headlight: OFF to ON
- Stop light: OFF to ON
- Rear defogger switch: OFF to ON
(4) Turn the ignition switch to the "LOCK" (OFF) position.
Did the measured voltage increase?
Go to Step 2. Replace the generator. Then confirm that the malfunction symptom is eliminated.