For 1990-2009 cars

## Headlamps Inoperative - High Beams Buick

Step | Action | Value(s) | Yes | No
--- | --- | --- | --- | ---
1 | Did you perform the entire headlights system check? | -- | Go to Step 2 | Go to Headlight System Check
2 |

1. Disconnect the headlamp dimmer switch connector C202.
2. Place the headlamp switch in the ON position.
3. Connect a fused jumper from the headlamp dimmer switch connector C202 cavity B5 (PPL) to ground.

Do the headlamps turn from low beams to high beams?

--

Go to Step 5

Go to Step 3

3 |

1. Disconnect the lamp control module (LCM) connector C1.
2. Connect a fused jumper from the LCM connector C1 cavity G (RED) to cavity B (LT GRN).

Do the high beam headlamps light?

--

Go to Step 7

Go to Step 4

4 | Repair the open in CKT 11 (LT GRN). Refer to Wiring Repairs in Wiring Systems. Is the repair complete? | -- | Go to Headlight System Check | --
5 | Inspect for an open in CKT 251 (BLK/WHT) between the headlamp dimmer switch connector C202 and S293. Refer to Testing for Continuity in Wiring Systems. Is CKT 251 OK? | -- | Go to Step 6 | Go to Step 9
6 | Replace the headlamp dimmer switch. Refer to Dimmer Switch Assembly - Disassemble - Off Vehicle and Dimmer Switch Assembly - Assemble - Off Vehicle in Steering Wheel and Column-Tilt. Is the headlamp dimmer switch replacement complete? | -- | Go to Headlight System Check | --
7 | Inspect for an open in CKT 524 (PPL) between the LCM and the headlamp dimmer switch connector C202. Refer to Testing for Continuity in Wiring Systems. Is CKT 524 OK? | -- | Go to Step 8 | Go to Step 9
8 | Replace the LCM. Refer to Lamp Control Module Replacement . Is the LCM replacement complete? | -- | Go to Headlight System Check | --
9 | Repair the suspect wiring. Refer to Wiring Repairs in Wiring Systems. Is the repair complete? | -- | Go to Headlight System Check | --

## Headlamps Inoperative - High Beams Oldsmobile

Step | Action | Value(s) | Yes | No
--- | --- | --- | --- | ---
1 | Did you perform the entire headlights system check? | -- | Go to Step 2 | Go to Headlight System Check
2 |

1. Disconnect the lamp control module (LCM) connector C1 and C2.
2. Connect a DMM from the LCM connector C1 cavity E (RED) to ground.

Is the voltage within the specified range?

10-15V

Go to Step 3

Go to Step 9

3 | Use a test lamp in order to backprobe the headlamp switch connector cavity D (RED) to ground. Does the test lamp light? | -- | Go to Step 4 | Go to Step 10
4 |

1. Remove the headlamp relay (position J) from the RH IP fuse block.
2. Connect a DMM from the headlamp relay (position J) cavity 30 (RED) to ground.

Is the voltage within the specified range?

10-15V

Go to Step 5

Go to Step 11

5 |

1. Place the headlamp switch in the HEAD position.
2. Connect a DMM from the headlamp relay (position J) cavity 85 (YEL) to ground.

Is the voltage within the specified range?

10-15V

Go to Step 6

Go to Step 12

6 | Connect a DMM from the headlamp relay (position J) cavity 30 (RED) to cavity 86 (BLK). Is the voltage within the specified range? | 10-15V | Go to Step 7 | Go to Step 14
7 | Connect a fused jumper from the headlamp relay (position J) cavity 30 (RED) to cavity 87 (LT BLU). Do the high beam headlamps light? | -- | Go to Step 15 | Go to Step 8
8 |

1. Leave the fused jumper in place.
2. Use a test lamp in order to backprobe the headlamp dimmer switch connector C202 from cavity C5 (LT BLU) to ground

Does the test lamp light?

--

Go to Step 17

Go to Step 16

9 | Repair the open in CKT 242 (RED) between S201 and the lamp control module (LCM). Refer to Wiring Repairs in Wiring Systems. Is the circuit repair complete? | -- | Go to Headlight System Check | --
10 | Repair the open in CKT 242 (RED) between S201 and the headlamp switch. Refer to Wiring Repairs in Wiring Systems. Is the circuit repair complete? | -- | Go to Headlight System Check | --
11 | Repair the open in CKT 242 (RED) between S201 and the RH IP fuse block. Refer to Wiring Repairs in Wiring Systems. Is the circuit repair complete? | -- | Go to Headlight System Check | --
12 | Inspect for an open in CKT 10 (YEL) between the headlamp switch and the RH IP fuse block. Refer to Testing for Continuity in Wiring Systems. Is CKT 10 OK? | -- | Go to Step 13 | Go to Step 19
13 | Replace the headlamp switch. Refer to Headlamp Switch Replacement . Is the headlamp switch replacement complete? | -- | Go to Headlight System Check | --
14 | Repair the open in CKT 1450 (BLK) between S308 and the RH IP fuse block. Refer to Wiring Repairs in Wiring Systems. Is the circuit repair complete? | -- | Go to Headlight System Check | --
15 | Replace the headlamp relay (position J). Is the relay replacement complete? | -- | Go to Headlight System Check | --
16 | Repair the open in CKT 1346 (LT BLU) between the headlamp dimmer switch connector C202 and the RH IP fuse block. Refer to Wiring Repairs in Wiring Systems. Is the circuit repair complete? | -- | Go to Headlight System Check | --
17 | Inspect for an open in CKT 11 (LT GRN) between the headlamp dimmer switch connector C202 and S245. Refer to Testing for Continuity in Wiring Systems. Is CKT 11 OK? | -- | Go to Step 18 | Go to Step 19
18 | Replace the headlamp dimmer switch. Refer to Dimmer Switch Assembly - Disassemble - Off Vehicle and Dimmer Switch Assembly - Assemble - Off Vehicle in Steering Wheel and Column-Tilt. Is the headlamp dimmer switch replacement complete? | -- | Go to Headlight System Check | --
19 | Repair the suspect wiring. Refer to Wiring Repairs in Wiring Systems. Is the repair complete? | -- | Go to Headlight System Check | --

## Headlamps Inoperative - High Beams Pontiac

Step | Action | Value(s) | Yes | No
--- | --- | --- | --- | ---
1 | Did you perform the entire headlights system check? | -- | Go to Step 2 | Go to Headlight System Check
2 | Operate the headlamp dimmer switch in the high and low positions. Do the low beam headlamps operate? | -- | Go to Step 6 | Go to Step 3
3 | Use a test lamp in order to backprobe the headlamp switch connector cavity A (RED) to ground. Does the test lamp light? | -- | Go to Step 4 | Go to Step 10
4 |

1. Disconnect the headlamp switch connector.
2. Connect a fused jumper from the headlamp switch connector cavity A (RED) to cavity D (YEL).

Do the high beam headlamps light?

--

Go to Step 11

Go to Step 5

5 |

1. Leave the fused jumper in place.
2. Use a test lamp in order to backprobe the headlamp dimmer switch connector C202 from cavity C5 (YEL) to ground

Does the test lamp light?

--

Go to Step 6

Go to Step 12

6 |

1. Reconnect the headlamp switch.
2. Disconnect the headlamp dimmer switch connector C202.
3. Connect a fused jumper from the headlamp dimmer switch connector C202 cavity C5 (YEL) to cavity B5 (LT GRN).

Do the high beam headlamps light?

--

Go to Step 14

Go to Step 7

7 | Is the vehicle equipped with lamp monitoring? | -- | Go to Step 8 | Go to Step 13
8 |

1. Disconnect the lamp monitor control module connectors C1 and C2.
2. Connect a fused jumper from the lamp monitor control module connector C2 cavity A (LT GRN) to connector C1 cavity R (LT GRN).
3. Place the headlamp dimmer switch in the HIGH position

Do the high beam headlamps light?

--

Go to Step 9

Go to Step 15

9 | Replace the lamp monitor control module. Refer to Instrument Panel Lamp Dimmer Replacement in Instrument Panel, Gauges and Console. Is the lamp monitor control module replacement complete? | -- | Go to Headlight System Check | --
10 | Repair the open in CKT 242 (RED) between S201 and the headlamp switch. Refer to Wiring Repairs in Wiring Systems. Is the circuit repair complete? | -- | Go to Headlight System Check | --
11 | Replace the headlamp switch. Refer to Headlamp Switch Replacement . Is the headlamp switch replacement complete? | -- | Go to Headlight System Check | --
12 | Repair the open in CKT 10 (YEL) between the headlamp switch and the headlamp dimmer switch connector C202. Refer to Wiring Repairs in Wiring Systems. Is the circuit repair complete? | -- | Go to Headlight System Check | --
13 | Inspect for an open in CKT 11 (LT GRN) between the headlamp dimmer switch connector C202 and S245. Refer to Testing for Continuity in Wiring Systems. Is CKT 11 OK? | -- | Go to Step 14 | Go to Step 17
14 | Replace the headlamp dimmer switch. Refer to Dimmer Switch Assembly - Disassemble - Off Vehicle and Dimmer Switch Assembly - Assemble - Off Vehicle in Steering Wheel and Column-Tilt. Is the headlamp dimmer switch replacement complete? | -- | Go to Headlight System Check | --
15 | Inspect for an open in CKT 11 (LT GRN) between the headlamp dimmer switch connector C202 and the lamp monitor control module. Refer to Testing for Continuity in Wiring Systems. Is CKT 11 OK? | -- | Go to Step 16 | Go to Step 17
16 | Inspect for an open in CKT 1311 (LT GRN) between the lamp monitor control module and S259. Refer to Testing for Continuity in Wiring Systems. Is CKT 1311 OK? | -- | Go to Step 14 | Go to Step 17
17 | Repair the suspect wiring. Refer to Wiring Repairs in Wiring Systems. Is the repair complete? | -- | Go to Headlight System Check | --