Charge Indicator Malfunction

Charge Indicator Malfunction

Diagnostic Instructions

* Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure. Initial Inspection and Diagnostic Overview
* Review Strategy Based Diagnosis for an overview of the diagnostic approach.
* Diagnostic Procedure Instructions provides an overview of each diagnostic category.

Circuit/System Description

The engine control module (ECM) uses the generator turn ON signal circuit to control the load of the generator on the engine. A high side driver in the ECM applies a voltage to the voltage regulator. This signals the voltage regulator to turn the field circuit ON and OFF. The ECM monitors the state of the generator turn ON signal circuit. The ECM should detect a low voltage on the generator turn on signal circuit when the ignition is ON and the engine is OFF or when the charging system malfunctions. With the engine running, the ECM should detect high voltage on the generator turn on signal circuit. The ECM performs key ON and RUN tests to determine the status of the generator turn on signal circuit. If a malfunction is detected the ECM will illuminate the charge indicator in the instrument panel cluster (IPC).

Circuit/System Testing

1. Ignition ON, verify that the charge indicator illuminates during the self test when the ignition is turned ON.

• If the charge indicator does not illuminate, replace the IPC.

2. Ignition ON, verify that the charge indicator illuminates and turns OFF during the self test when the ignition is turned ON.

• If the charge indicator remains illuminated, disconnect the generator connector. If the charge indicator turns OFF, refer to Charging System Test. Charging System Test

3. Ignition OFF, test for greater than 1.0 ohm of resistance between the generator turn on signal circuit terminal B and ground.

• If less than the specified value, test the circuit for a short to ground.

4. If all circuits test normal, test or replace the IPC.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure. Verification Tests