For 1990-2009 cars

Step | Action | Yes | No
--- | --- | --- | ---
Schematic Reference: Headlights Schematics Connector End View Reference: Master Electrical Component List
1 | Did you perform the Diagnostic System Check - Vehicle? | Go to Step 2 | Go to Diagnostic System Check - Vehicle
2 | Do the headlamps and DRL operate properly? | Go to Step 3 | Go to Headlamps Inoperative - Low Beams
3 |

1. Install the scan tool.
2. Turn ON the ignition, with the engine OFF.
3. Place the headlamp switch in the AUTO position.
4. With a scan tool, observe the Twilight Enable parameter in the instrument panel module (IPM) exterior lamps data list.

Does the Twilight Enable parameter display ENABLED?

Go to Step 8

Go to Step 4

4 |

1. Turn OFF the ignition.
2. Disconnect the turn signal/multifunction switch C3 harness connector.
3. Connect a 3-amp fused jumper between the turn signal/multifunction switch twilight sentinel display signal circuit at the turn signal/multifunction switch C3 harness connector and the ground circuit of the turn signal/multifunction switch at the C3 harness connector.
4. Turn ON the ignition, with the engine OFF.
5. With a scan tool, observe the Twilight Enable parameter in the IPM exterior lamps data list.

Does the Twilight Enable parameter display ENABLED?

Go to Step 7

Go to Step 5

5 | Test the turn signal/multifunction switch ground circuit for an open or high resistance. Refer to Circuit Testing and Wiring Repairs . Did you find and correct the condition? | Go to Step 11 | Go to Step 6
6 | Test the twilight sentinel display signal circuit for an open, high resistance, or short to voltage. Refer to Circuit Testing and Wiring Repairs . Did you find and correct the condition? | Go to Step 11 | Go to Step 8
7 | Inspect for poor connections at the C3 harness connector of the turn signal/multifunction switch. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs . Did you find and correct the condition? | Go to Step 11 | Go to Step 9
8 | Inspect for poor connections at the harness connector of the IPM. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs . Did you find and correct the condition? | Go to Step 11 | Go to Step 10
9 | Replace the turn signal/multifunction switch. Refer to Turn Signal Multifunction Switch Replacement . Did you complete the replacement? | Go to Step 11 | --
10 | Replace the IPM. Refer to Control Module References for replacement, setup, and programming. Did you complete the replacement? | Go to Step 11 | --
11 | Operate the system in order to verify the repair. Did you correct the condition? | System OK | Go to Step 2