• | 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. |
Circuit | Short to Ground | Open/High Resistance | Short to Voltage | Signal Performance |
---|---|---|---|---|
MIL Voltage Supply | P1661 | P1661 | -- | -- |
MIL Control | P1661/MIL ON | P1661 | P1660 | -- |
The malfunction indicator lamp (MIL) is located on the instrument panel cluster (IPC). The MIL informs the driver that an emission system fault has occurred and that the engine control system requires service. The control module monitors the MIL control circuit for conditions that are incorrect for the commanded states of the MIL.
• | The ignition is ON or the engine is running. |
• | The ignition 1 voltage is more than 11 volts. |
• | The DTCs runs continuously when the above conditions are met. |
The engine control module (ECM) detects the MIL control circuit is shorted to voltage.
The ECM detects the MIL control circuit is open or shorted to ground.
DTC P1660 and P1661 are Type B DTCs.
DTC P1660 and P1661 are Type B DTCs.
Powertrain Diagnostic Trouble Code (DTC) Type Definitions
Control Module References for scan tool information
⇒ | If the MIL does not illuminate, test the control circuit for a short to voltage, short to ground, or an open/high resistance. If the circuit tests normal, replace the IPC/bulb. |
⇒ | If the MIL illuminates, inspect for a poor connection or replace the control module. |
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
• | Control Module References for ECM replacement, setup, and programming |