Colorado 4WD L5-3.7L (2007)
Malfunction Indicator Lamp: Testing and Inspection
Malfunction Indicator Lamp (MIL) Always On
Malfunction Indicator Lamp (MIL) Always On
Circuit Description
Battery positive voltage is supplied to the malfunction indicator lamp (MIL) through a logic module in the instrument panel cluster (IPC). The
powertrain control module (PCM) turns the MIL ON by grounding the MIL control circuit.
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 bulb test and a system test.
* A DTC will be stored if a MIL is requested by the diagnostic.
MIL Illumination
* The MIL will illuminate with the 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 no longer present.
* If the MIL is illuminated and then the engine stalls, the MIL will remain illuminated as 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.
Diagnostic Aids
If the problem is intermittent, refer to Intermittent Conditions. See: Powertrain Management/Computers and Control Systems/Testing and
Inspection/Initial Inspection and Diagnostic Overview/Intermittent Conditions
Test Description
Step 1 - Step 6
The number below refers to the step number on the diagnostic table.
2. This step determines if the condition is with the MIL control circuit or the PCM.
