Malfunction Indicator Lamp (MIL) ON Steady

Malfunction Indicator Lamp On Steady





Circuit Description
When the ignition is turned ON, the MIL will momentarily flash ON then OFF and remain ON until the engine is running, if no Diagnostic Trouble Codes (DTC) are stored. Battery voltage is supplied through the ignition switch directly to the MIL telltale. The Powertrain Control Module (PCM) controls the MIL by providing a ground path through the MIL control circuit to turn ON the MIL.

Test Description





Number(s) below refer to the step number(s) on the Diagnostic Tables.
1. The Powertrain OBD System Check prompts the technician to complete some basic checks and store the freeze frame and failure records data on the scan tool if applicable. This creates an electronic copy of the data taken when the malfunction occurred. The information is then stored in the scan tool for later reference.
2. When the ignition is turned ON, the MIL should momentarily flash ON and OFF then remain ON until the engine is running or if an emission related DTC is stored.
3. This step checks the ability of the PCM to control the MIL. The scan tool has the ability to command the MIL ON and OFF.
5. A shorted MIL circuit can be diagnosed with a scan tool. Refer to PCM Outputs Diagnosis.
6. For Instrument Panel Cluster (IPC) replacement procedures, refer to Instrument Panel of the service manual.
7. Replacement PCMs must be reprogrammed and the crankshaft position system variation procedure must be performed. Refer to the latest Isuzu Technical Communication System (ITCS) information for programming procedures and also refer to the CKP System Variation Learn Procedure.