Circuit Description
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 state of the MIL. For example, a failure condition exists if the control module detects low voltage when the MIL is commanded OFF, or high voltage when the MIL is commanded ON. If the control module detects an improper voltage on the MIL control circuit, DTC P0650 will set.
DTC Descriptor
This diagnostic procedure supports the following DTC:
DTC P0650 Malfunction Indicator Lamp (MIL) Control Circuit
Conditions for Running the DTC
| • | The ignition is ON. |
| • | The ignition voltage is between 10-18 volts. |
| • | DTC P0650 runs continuously when the above conditions are met. |
Conditions for Setting the DTC
The control module detects that the commanded state of the MIL driver and the actual state of the control circuit do not match for 5 seconds.
Action Taken When the DTC Sets
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
| • | 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. |
| • | Clear the MIL and the DTC with a scan tool. |
Test Description
The number below refers to the step number on the diagnostic table.
Step | Action | Yes | No |
|---|---|---|---|
Schematic Reference: Instrument Cluster Schematics or Engine Controls Schematics Connector End View Reference: Instrument Panel, Gages, and Console Connector End Views or Engine Control Module Connector End Views | |||
1 | Did you perform the Diagnostic System Check - Vehicle? | Go to Step 2 | |
2 | Command the malfunction indicator lamp (MIL) ON and OFF with a scan tool. Does the MIL turn ON and OFF when commanded with a scan tool? | Go to Step 3 | Go to Step 4 |
3 |
Does the DTC fail this ignition? | Go to Step 4 | Go to Testing for Intermittent Conditions and Poor Connections |
4 | Is the MIL always ON? | Go to Step 6 | Go to Step 5 |
5 | Inspect the fuse that supplies voltage to the MIL. Is the fuse open? | Go to Step 14 | Go to Step 7 |
Is the MIL OFF? | Go to Step 18 | Go to Step 11 | |
7 |
Is the MIL illuminated? | Go to Step 13 | Go to Step 8 |
8 | Did the fuse in the jumper wire open? | Go to Step 16 | Go to Step 9 |
9 |
Does the test lamp illuminate? | Go to Step 10 | Go to Step 15 |
10 | Test the MIL control circuit for an open or high resistance. Refer to Circuit Testing and Wiring Repairs . Did you find and correct a condition? | Go to Step 19 | Go to Step 12 |
11 | Test the MIL control circuit for a short to ground. Refer to Circuit Testing and Wiring Repairs . Did you find and correct the condition? | Go to Step 19 | Go to Step 12 |
12 | Test for an intermittent and for a poor connection at the IPC. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs . Did you find and correct the condition? | Go to Step 19 | Go to Step 17 |
13 | Test for an intermittent and for a poor connection at the ECM. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs . Did you find and correct the condition? | Go to Step 19 | Go to Step 18 |
14 | Repair the short to ground in the voltage supply circuit. Refer to Wiring Repairs . Did you complete the repair? | Go to Step 19 | -- |
15 | Repair the open in the ignition 1 voltage supply circuit. Refer to Wiring Repairs . Did you complete the repair? | Go to Step 19 | -- |
16 | Repair the short to voltage in the MIL control circuit. Refer to Wiring Repairs . Did you complete the repair? | Go to Step 19 | -- |
17 | Replace the IPC. Refer to Instrument Cluster Replacement . Did you complete the replacement? | Go to Step 19 | -- |
18 | Replace the ECM. Refer to Control Module References for replacement, setup, and programming. Did you complete the replacement? | Go to Step 19 | -- |
19 |
Did the DTC fail this ignition? | Go to Step 2 | Go to Step 20 |
20 | Observe the Capture Info with a scan tool. Are there any DTCs that have not been diagnosed? | System OK | |
