Circuit Description
When the ignition is turned ON, the malfunction indicator lamp (MIL) will momentarily flash ON then OFF and remain ON until the engine is running, if no diagnostic trouble codes (DTCs) are stored. 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.
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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.
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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.
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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.
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A shorted MIL circuit can be diagnosed with a scan tool. Refer to Powertrain Control Module Outputs Diagnosis .
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For Instrument Panel Cluster (IPC) replacement procedures, refer to Instrument Panel portion of the service manual.
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Replacement PCMs must be programmed. Refer to the latest Techline information for programming procedure.
Step | Action | Value(s) | Yes | No |
|---|---|---|---|---|
Was the Powertrain On-Board Diagnostic (OBD) System Check performed? | -- | |||
Turn the ignition switch ON, with the engine OFF. Is the MIL ON? | -- | |||
Does the MIL turn ON and OFF when commanded? | -- | |||
4 |
Is the MIL OFF? | -- | ||
Check the MIL control circuit for a short to ground and repair if necessary. Was a repair necessary? | -- | |||
Replace the Instrument Panel Cluster (IPC) Refer to Instrument Panel Replacement in Instrument Panel and Gauges. Is the action complete? | -- | -- | ||
Replace the PCM. Refer to Powertrain Control Module Replacement . Is the action complete? | -- | -- | ||
8 |
Does the engine start and continue to run? | -- | ||
9 |
Are any DTCs displayed that have not been diagnosed? | -- | Go to the Applicable DTC table | System OK |
