Headlight System - Automatic Control: Other Oldsmobile Cutlass VI

HANDLING PRECAUTIONS

1. Discharge personal static electricity by momentarily touching metal grounding point on vehicle before touching electronic components.
2. DO NOT touch terminals on components or connectors with fingers or metal tools. When unplugging connectors, DO NOT let metal tool contact any exposed terminal.
3. Never jumper, ground, or use test probes on components or connectors unless specified in diagnosis. Always connect ground lead first.
4. DO NOT remove solid-state components from protective packaging until ready for installation. Touch packaging to ground before opening.
5. DO NOT bump or drop components. DO NOT put component on metal work bench, metal objects, or electrically operated components (such as radio, TV, or oscilloscope).

Both Low Beam Headlights Inoperative

1. Using test light, backprobe between U/H BEC Brown 68-pin connector C3 terminal A12 (Dark Blue wire) and ground. If test light illuminates, go to next step. If test light does not illuminate, go to step 3).
2. Using test light, backprobe between turn/headlight switch assembly 6-pin connector C1 terminal No. 34 (Dark Blue wire) and ground. If test light illuminates, go to step 4). If test light does not illuminate, go to step 5).
3. Replace U/H BEC. Recheck system operation.
4. Replace turn/headlight switch assembly. See appropriate «STEERING COLUMN SWITCHES»(ref-32838) article. Recheck system operation.
5. Repair open in circuit No. 1201 (Dark Blue wire) between turn/headlight switch assembly and U/H BEC. Recheck system operation.

Both High Beam Headlights Inoperative

1. Using test light, backprobe between U/H BEC Brown 68-pin connector C3 terminal B7 (Pink wire) and ground. If test light illuminates, go to next step. If test light does not illuminate, go to step 3).
2. Using test light, backprobe between turn/headlight switch assembly 6-pin connector C1 terminal No. 33 (Pink wire) and ground. If test light illuminates, go to step 4). If test light does not illuminate, go to step 5).
3. Replace U/H BEC. Recheck system operation.
4. Replace turn/headlight switch assembly. See appropriate «STEERING COLUMN SWITCHES»(ref-32838) article. Recheck system operation.
5. Repair open in circuit No. 1200 (Pink wire) between turn/headlight switch assembly and U/H BEC. Recheck system operation.

Both Low Beam & High Beam Headlights Inoperative, But DRL Operates Normally

1. Using test light, backprobe between turn/headlight switch assembly 6-pin connector C1 terminal No. 35 (Black wire) and ground. If test light illuminates, go to next step. If test light does not illuminate, go to step 3).
2. Repair open in circuit No. 150 (Black wire) between turn/headlight switch assembly and ground splice pack G201. Recheck system operation.
3. Replace turn/headlight switch assembly. See appropriate «STEERING COLUMN SWITCHES»(ref-32838) article. Recheck system operation.

Headlights Do Not Turn Off

1. Disconnect turn/headlight switch assembly 6-pin connector C1. If headlight turn off, go to next step. If headlights do not turn off, go to step 3).
2. Using DVOM, check resistance between turn/headlight switch assembly harness connector C1 terminals No. 33 (Pink wire) and No. 35 (Black wire). Check resistance between turn/headlight switch assembly harness connector C1 terminals No. 34 (Dark Blue wire) and No. 35 (Black wire). If resistance is infinite at both terminals, go tostep 4). If resistance is not infinite at both terminals, go to step 5).
3. Disconnect U/H BEC Brown 68-pin connector C3. If headlights turn off, go to step 6). If headlights do not turn off, go to step 7).
4. Locate and repair problem in BCM system. See «BODY CONTROL MODULE»(ref-32837) article. Recheck system operation.
5. Replace turn/headlight switch assembly. See «STEERING COLUMN SWITCHES»(ref-32838) article. Recheck system operation.
6. If low beams are on, repair short to ground in circuit No. 1201 (Dark Blue wire) between turn/headlight switch assembly and U/H BEC. If high beams are on, repair short to ground in circuit No. 1200 (Pink wire) between turn/headlight switch assembly and U/H BEC. Recheck system operation.
7. Disconnect U/H BEC Black 68-pin connector C2. If headlights turn off, go to next step. If headlights do not turn off, go to step 9).
8. Replace U/H BEC. Recheck system operation.
9. If low beams are on, repair short to ground in circuit No. 1201 (Dark Blue wire) between U/H BEC and any illuminated headlight. If high beams are on, repair short to ground in circuit No. 1200 (Pink wire) between U/H BEC and any illuminated headlight. Recheck system operation.

Foglights Are Inoperative

1. Using scan tool, check for BCM Diagnostic Trouble Codes (DTCs). If no BCM DTCs exist, go to next step. If BCM DTCs exist, go to step 3).
2. Connect scan tool. Turn headlight switch to PARK position. Using scan tool, command foglights on. If foglights illuminate, go to step 4). If foglights do not illuminate, go to step 5).
3. Repair problem in BCM system. See «BODY CONTROL MODULE»(ref-32837) article. Recheck system operation.
4. Using a fused jumper wire, backprobe between BCM Pink 24-pin connector C3 terminal A4 (Orange wire) and ground. If scan tool displays foglight input is ON, go to step 6). If scan tool does not display foglight input is ON, go to step 7).
5. Remove foglight relay from RH I/P BEC. Replace with known-good relay. Using scan tool, command foglights on. If foglights illuminate, go to step 8). If foglights do not illuminate, go to step 9).
6. Disconnect foglight switch connector. Connect a fused jumper wire between Orange wire terminal at foglight switch harness connector and ground. If scan tool displays foglight input is ON, go to step 10). If scan tool does not display foglight input is ON, go to step 11).
7. Replace BCM. See appropriate BODY CONTROL MODULE article. Recheck system operation.
8. Replace faulty foglight relay. Recheck system operation.
9. Replace RH I/P BEC. Recheck system operation.
10. Connect a fused jumper wire between Orange and Black/White wire terminals at foglight switch harness connector. If scan tool displays foglight input is ON, go to step 12). If scan tool does not display foglight input is ON, go to step 13).
11. Repair open in circuit No. 192 (Orange wire) between foglight switch and BCM connector C3. Recheck system operation.
12. Replace foglight switch. Recheck system operation.
13. Repair open in circuit No. 251 (Black/White wire) between foglight switch and ground splice pack G204. Recheck system operation.

Headlights Do Not Come On Automatically When Dark

1. Using scan tool, check for BCM Diagnostic Trouble Codes (DTCs). If no BCM DTCs exist, go to next step. If BCM DTCs exist, go to step 12).
2. Connect scan tool. Using scan tool, command automatic lamp control on. If headlights turn on, go to step 12). If headlights do not turn on, go to next step.
3. Using test light, backprobe between turn/headlight switch assembly 6-pin connector C1 terminal No. 36 (Dark Green wire) and ground. If test light illuminates, go to next step. If test light does not illuminate, go to step 5).
4. Remove automatic lamp control relay from U/H BEC. Install known-good relay. Using scan tool, command automatic lamp control on. If headlights turn on, go to step 6). If headlights do not turn on, go tostep 7).
5. Replace turn/headlight switch assembly. See «STEERING COLUMN SWITCHES»(ref-32838) article. Recheck system operation.
6. Replace faulty automatic lamp control relay. Recheck system operation.
7. Using test light, backprobe between U/H BEC Brown 68-pin connector C3 terminal B3 (Dark Green wire) and ground. If test light illuminates, go to next step. If test light does not illuminate, go tostep 9).
8. Using DVOM to check resistance, backprobe between U/H BEC connector C3 terminal A10 (Black wire) and ground. If resistance is0-2 ohms, go to step 10). If resistance is not 0-2 ohms, go to step 11).
9. Repair open in circuit No. 306 (Dark Green wire) between U/H BEC connector C3 and turn/headlight switch assembly. Recheck system operation.
10. Connect a fused jumper wire between U/H BEC connector C3 terminal C11 (Pink/White wire) and ground. If headlights turn on, go to step 12). If headlights do not turn on, go to step 13).
11. Repair open in circuit No. 150 ( wire) between U/H BEC connector C3 and ground splice pack G201. Recheck system operation.
12. Repair problem in BCM system. See «BODY CONTROL MODULE»(ref-32837) article. Recheck system operation.
13. Replace U/H BEC. Recheck system operation.

DRL Inoperative, But Headlights Operate Properly

1. Using scan tool, check for BCM Diagnostic Trouble Codes (DTCs). If no BCM DTCs exist, go to next step. If BCM DTCs exist, go to step 3).
2. Connect scan tool. Using scan tool, command DRL on. If DRL turn on, go to next step. If DRL do not turn on, go to step 4).
3. Repair problem in BCM system. See «BODY CONTROL MODULE»(ref-32837) article. Recheck system operation.
4. Remove DRL relay from U/H BEC. Install known-good relay. Using scan tool, command DRL on. If DRL turn on, go to next step. If DRL do not turn on, go to step 6).
5. Replace faulty DRL relay. Recheck system operation.
6. Using DVOM to check resistance, backprobe between U/H BEC Black 68-pin connector C2 terminal D11 (Gray wire) and ground. If resistance is 0-2 ohms, go to next step. If resistance is not 0-2 ohms, go to step 8).
7. Connect a fused jumper wire between U/H BEC Brown 68-pin connector C3 terminal B12 (Light Green/Black wire) and ground. If DRL turn on, go to step 9). If DRL do not turn on, go to step 10).
8. Disconnect DRL resistor. Using DVOM, check resistance between DRL resistor harness connector terminals "A" (Gray wire) and "B" (Black wire). If resistance is 0.25-0.37 ohms, go to step 12). If resistance is not 0.25-0.37 ohms, go to step 11).
9. Repair open in circuit No. 592 (Light Green/Black wire) betweenU/H BEC and BCM connector C1. Recheck system operation.
10. Replace U/H BEC. Recheck system operation.
11. Using DVOM, check resistance between DRL resistor harness connector terminal "B" (Black wire) and ground. If resistance is 0-2 ohms, go to step 13). If resistance is not 0-2 ohms, go to step 14).
12. Replace DRL resistor. Recheck system operation.
13. Repair open in circuit No. 589 (Gray wire) between DRL resistor and U/H BEC connector C2. Recheck system operation.
14. Repair open in circuit No. 1350 (Black wire) between DRL resistor and ground splice pack G101. Recheck system operation.