P0650

CIRCUIT DESCRIPTION
There should always be a steady Malfunction Indicator Lamp (MIL) when the ignition switch is ON and the engine is not running. The ignition voltage is supplied within the instrument cluster to the indicator bulb. The Engine Control Module (ECM) controls the lamp by grounding the control circuit via an internal solid state device called a driver.

CONDITIONS FOR RUNNING THE DTC
^ The engine speed must exceed 40 RPM.
^ The battery voltage must be between 7.5-14 volts.

CONDITIONS FOR SETTING THE DTC
The ECM determines there is an open, a short to ground, or a short to voltage in the MIL control circuit.

ACTION TAKEN WHEN THE DTC SETS
^ The control module illuminates the Malfunction Indicator Lamp (MIL) on the second consecutive ignition cycle that the diagnostic runs and fails.
^ The control module records the operating conditions at the time the diagnostic fails. The first time the diagnostic fails, the control module stores this information in the Failure Records. If the diagnostic reports a failure on the second consecutive ignition cycle, the control module records the operating conditions at the time of the failure. The control module writes the operating conditions to the Freeze Frame and updates the Failure Records.

CONDITIONS FOR CLEARING THE MIL/DTC
^ The control module turns OFF the Malfunction Indicator Lamp (MIL) after 3 consecutive ignition cycles that the diagnostic runs and does not fail.
^ A current DTC, Last Test Failed, clears when the diagnostic runs and passes.
^ A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other emission related diagnostic.
^ Use a scan tool in order to clear the MIL and the DTC.

DIAGNOSTIC AIDS
^ Use the J 35616-A Connector Test Adapter Kit for any test that requires probing the ECM harness connector or a component harness connector.
^ If the ignition feed circuit is suspected of being open, check if the other bulbs on that circuit illuminate.
^ Check to see if instrument panel fuse 15 is open.
^ An intermittent may be caused by the following:
- Corrosion
- A mis-routed harness
- A rubbed through wire insulation
- A broken wire inside the insulation

Refer to Testing for Intermittent and Poor Connections for the intermittents.

TEST DESCRIPTION

Steps 1-4:

Steps 5-13:

The numbers below refer to the step numbers on the diagnostic table.
2. The MIL should remain ON when the ignition is turned ON and the engine is OFF.
3. If the other indicator lamps in the instrument cluster are functioning, the feed circuit is OK.
12. After the engine starts, the MIL should illuminate briefly and turn OFF.