For 1990-2009 cars

Step | Action | Yes | No
--- | --- | --- | ---
Schematic Reference: Headlights/Daytime Running Lights (DRL) 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 | Turn the headlamp switch to the OFF position. Do the low and high beam headlamps remain OFF? | Go to Testing for Intermittent Conditions and Poor Connections | Go to Step 3
3 | Are the high beam headlamps ON at all times when the low beams are ON? | Go to Step 4 | Go to Step 9
4 | Disconnect the body control module (BCM) connector C1 Are the high beam headlamps illuminated? | Go to Step 5 | Go to Step 6
5 | Test for a short to ground in the headlamp high beam relay control circuit. Refer to Circuit Testing and Wiring Repairs . Did you find and correct the condition? | Go to Step 20 | Go to Step 14
6 |

1. Reconnect the BCM connector C1.
2. Disconnect the turn signal/multifunction switch connector C2.

Are the high beam headlamp illuminated?

Go to Step 7

Go to Step 16

7 | Test for a short to ground in the flash to pass switch signal circuit. Refer to Circuit Testing and Wiring Repairs . Did you find and correct the condition? | Go to Step 20 | Go to Step 8
8 | Test for a short to ground in the headlamp switch high beam signal circuit. Refer to Circuit Testing and Wiring Repairs . Did you find and correct the condition? | Go to Step 20 | Go to Step 16
9 | Disconnect the BCM connector C2. Are the low beam headlamps ON? | Go to Step 10 | Go to Step 11
10 | Test for a short to ground in the headlamp low beam relay control circuit. Refer to Circuit Testing and Wiring Repairs . Did you find and correct the condition? | Go to Step 20 | Go to Step 14
11 |

1. Reconnect the BCM connector C2.
2. Disconnect the turn signal/multifunction switch connector C3.

Are the low beam headlamps ON?

Go to Step 12

Go to Step 15

12 | Test for the following in the headlamp switch OFF signal circuit:

• | An open

• | A poor connection

• | A short to battery positive voltage

Refer to Circuit Testing and Wiring Repairs .

Did you find and correct the condition?

Go to Step 20

Go to Step 13

13 | Test for a short to ground in the headlamp switch headlamps ON signal circuit. Refer to Circuit Testing and Wiring Repairs . Did you find and correct the condition? | Go to Step 20 | Go to Step 16
14 | Inspect for poor connections at the underhood fuse block . Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs . Did you find and correct the condition? | Go to Step 20 | Go to Step 17
15 | Inspect for poor connections at 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 20 | Go to Step 18
16 | Inspect for poor connections at the BCM. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs . Did you find and correct the condition? | Go to Step 20 | Go to Step 19
17 | Replace the underhood fuse block. Refer to Underhood Electrical Center or Junction Block Bracket Replacement . Did you complete the replacement? | Go to Step 20 | --
18 | Replace the turn signal/multifunction switch. Refer to Turn Signal Multifunction Switch Replacement . Did you complete the replacement? | Go to Step 20 | --
19 | Replace the BCM. Refer to Control Module References for replacement, setup, and programming. Did you complete the repair? | Go to Step 20 | --
20 | Operate the system in order to verify the repair. Did you correct the condition? | System OK | Go to Step 3