• | Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure. |
• | Review Strategy Based Diagnosis for an overview of the diagnostic approach. |
• | Diagnostic Procedure Instructions provides an overview of each diagnostic category. |
The engine control module (ECM) monitors the system voltage to ensure that the voltage stays within the proper range. Damage to components and incorrect data may occur when the voltage is out of range.
• | The vehicle speed is below 40 km/h(25 mph). |
• | The system voltage is below 11 volts or above 16 volts. |
• | Engine speed is above 1,500 RPM. |
The ECM detects a system voltage out of range for 2 seconds.
• | The ECM will command the charge indicator and or warning message to be illuminated on the instrument panel cluster (IPC) and the driver information center (DIC), if equipped. |
• | The ECM will not illuminate the malfunction indicator lamp (MIL). |
• | The ECM will store conditions, which were present when the DTC set as Fail Records data only. |
• | The ECM will command the message OFF after one trip in which the diagnostic test has been run and passed. |
• | The history DTC will clear after 40 consecutive warm-up cycles have occurred without a malfunction. |
Starting and Charging Schematics
Engine Electrical Connector End Views
Charging System Description and Operation
Engine running, observe the scan tool ECM Ignition 1 signal parameter. The ignition 1 signal parameter should read between 11.5 volts - 15.5 volts.
⇒ | If greater than the specified value, test the Ignition 1 and ground circuits of the ECM for an open/high resistance. If the circuits test normal replace the ECM. |
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
Control Module References for ECM replacement, setup, and programming