Circuit Description
The malfunction indicator lamp (MIL) is a light emitting diode (LED) that is controlled by a logic circuit and the powertrain control module (PCM). The PCM pulls the MIL control circuit low in order to illuminate the LED.
MIL Operation
The MIL and the logic circuit are located on the instrument panel cluster (IPC).
MIL Function
| • | The MIL informs the driver that a malfunction has occurred and the vehicle should be taken in for service as soon as possible. |
| • | The MIL illuminates during a functional test of the MIL circuit and LED. |
| • | A DTC will be stored if a MIL is requested by the PCM. |
MIL Illumination
| • | The MIL will illuminate with ignition switch ON and the engine not running. |
| • | The MIL will turn OFF when the engine is started. |
| • | The MIL will remain ON if the self-diagnostic system has detected a malfunction. |
| • | The MIL may turn OFF if the malfunction is not present. |
| • | If the MIL is illuminated and then the engine stalls, the MIL will remain illuminated so long as the ignition switch is ON. |
| • | If the MIL is not illuminated and the engine stalls, the MIL will not illuminate until the ignition switch is cycled OFF, then ON. |
Test Description
The number below refers to the step number on the diagnostic table.
Step | Action | Values | Yes | No |
|---|---|---|---|---|
Schematic Reference: Engine Controls Schematics Connector End View Reference: Powertrain Control Module Connector End Views or Engine Controls Connector End Views | ||||
1 | Did you perform the Diagnostic System Check-Engine Controls? | -- | Go to Step 2 | |
2 |
Does the MIL turn ON and OFF when commanded with a scan tool? | -- | Go to Intermittent Conditions | Go to Step 3 |
Is DTC P0650 set? | -- | Go to DTC P0650 | Go to Step 4 | |
4 |
Did you complete the repair or replacement? | -- | Go to Step 5 | -- |
5 | Turn OFF the ignition for 30 seconds. Does the vehicle operate correctly, without any MIL illumination and without any stored DTCs? | -- | System OK | |
