For 1990-2009 cars

Step | Action | Yes | No
--- | --- | --- | ---
Schematic Reference: Exterior Lights Schematics . Connector End View Reference: Component Connector End Views .
1 | Did you perform the Diagnostic System Check - Vehicle? | Go to Step 2 | Go to Diagnostic System Check - Vehicle .
2 |

1. Place the headlamp switch in the Low Beam position.
2. Turn ON the flash to pass switch.

Do the high beam headlamps illuminate momentarily?

Go to Testing for Intermittent Conditions and Poor Connections .

Go to Step 3

3 |

1. Place the headlamp switch in the ON position.
2. Connect a fused jumper from ground to the headlamp switch flash to pass signal circuit terminal of the headlamp dimmer switch connector.

Do the high beam headlamps illuminate?

Go to Step 6

Go to Step 4

4 | Test the headlamp switch flash to pass signal circuit for high resistance or an open. Refer to Circuit Testing and Wiring Repairs . Did you find and correct the condition? | System OK | Go to Step 5
5 | Inspect for poor connections at the harness connector of the body control module (BCM). Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs . Did you find and correct the condition? | System OK | Replace the BCM. Refer to Control Module References , for replacement, setup, and programming.
6 | Inspect for poor connections at the harness connector of the dimmer switch. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs . Did you find and correct the condition? | System OK | Replace the headlamp dimmer switch. Refer to Turn Signal Switch Replacement .