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 | Are both high beam headlamps inoperative? | Go to Step 3 | Go to Step 8
3 |

1. Install the scan tool.
2. Turn ON the ignition, with the engine OFF.
3. Turn ON the high beam headlamps.
4. With the scan tool, observe the High Beam Select Switch parameter in the instrument panel module (IPM) Inputs data list.

Does the data parameter display ACTIVE?

Go to Step 5

Go to Step 4

4 |

1. Turn OFF the ignition.
2. Disconnect the turn signal/multifunction switch C4 harness connector.
3. Connect a 3-amp fused jumper between the headlamp high beam switch signal circuit and the ground circuit at the turn signal/multifunction switch C4 harness connector.
4. Turn ON the ignition, with the engine OFF.
5. With a scan tool, observe the High Beam Select Switch parameter in the instrument panel module (IPM) inputs data list.

Does the High Beam Select Switch parameter display ACTIVE?

Go to Step 13

Go to Step 11

5 |

1. Turn OFF the ignition.
2. Disconnect the headlamp HIGH BEAM relay located in the underhood fuse block. Refer to Relay Replacement .
3. Connect a test lamp between the headlamp high beam relay control side supply voltage circuit and the headlamp high beam relay control circuit.
4. Turn ON the ignition, with the engine OFF.
5. Turn ON the high beam headlamps.

Does the test lamp illuminate?

Go to Step 6

Go to Step 10

6 | Connect a test lamp between the headlamp high beam relay switch side supply voltage circuit and a ground. Does the test lamp illuminate? | Go to Step 7 | Go to Step 18
7 |

1. Turn OFF the ignition.
2. Connect a 40-amp fused jumper between the headlamp high beam relay switch side supply voltage circuit and the headlamp high beam supply voltage circuit.
3. Turn ON the ignition, with the engine OFF.

Do both of the high beam headlamps illuminate?

Go to Step 14

Go to Step 8

8 |

1. Disconnect the inoperative high beam headlamp bulb.
2. Connect a test lamp between the high beam headlamp supply voltage circuit at the inoperative high beam headlamp bulb and the ground circuit of the inoperative high beam headlamp bulb.

Does the test lamp illuminate?

Go to Step 16

Go to Step 9

9 | Test the headlamp high beam supply voltage circuit for an open or high resistance. Refer to Circuit Testing and Wiring Repairs . Did you find and correct the condition? | Go to Step 23 | Go to Step 17
10 | Test the headlamp high beam relay control 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 23 | Go to Step 15
11 | 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 23 | Go to Step 12
12 | Test the headlamp high beam switch 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 23 | Go to Step 15
13 | Inspect for poor connections at the C4 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 23 | Go to Step 19
14 | Inspect for poor connections at the headlamp high beam relay. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs . Did you find and correct the condition? | Go to Step 23 | Go to Step 20
15 | 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 23 | Go to Step 21
16 | Inspect for poor connections at the harness connector of the inoperative high beam headlamp. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs Did you find and correct the condition? | Go to Step 23 | Go to Step 22
17 | Locate and repair an open or high resistance in the headlamp ground circuit. Refer to Circuit Testing and Wiring Repairs . Did you complete the repair? | Go to Step 23 | --
18 | Locate and repair an open or high resistance in the switch side supply voltage circuit of the headlamp high beam relay. Refer to Circuit Testing and Wiring Repairs . Did you complete the repair? | Go to Step 23 | --
19 | Replace the turn signal/multifunction switch. Refer to Turn Signal Multifunction Switch Replacement . Did you complete the replacement? | Go to Step 23 | --
20 | Replace the headlamp high beam relay. Refer to Relay Replacement . Did you complete the replacement? | Go to Step 23 | --
21 | Replace the IPM. Refer to Control Module References for replacement, setup, and programming. Did you complete the replacement? | Go to Step 23 | --
22 | Replace the inoperative high beam headlamp bulb. Refer to High Intensity Discharge Headlamp Replacement . Did you complete the replacement? | Go to Step 23 | --
23 | Operate the system in order to verify the repair. Did you correct the condition? | System OK | Go to Step 2