Questions and Answers
Pontiac Grand Prix DRLs Not Working
Q. I have a 2001 Pontiac Grand Prix 3.8 liter and my DRL have quit working. Everything else on the car works including the "Automatic ON" for the Headlights. It has an automatic transmission. I have checked the 10A fuse in the passenger side fuse box but I have no wiring diagram available. Can you tell me what the problem might be or how to figure it out.
I am Navy and stationed overseas with no garages around that can help. I would appreciate any help you can give me.
Thank you,
KevinA. Here is the troubleshooting procedure for the Daytime Running Lights (DRL).
Daytime Running Lamps (DRL) Inoperative
| Step | Action | Yes | No | 1 | Was the Lighting System Diagnostic System Check performed? | Go to Step 2 | Go to Diagnostic System Check - Lighting Systems |
| 2 |
Important: Vehicle shift lever must be out of the PARK position in order for the daytime running lamps (DRL) to operate.
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Go to Testing for Intermittent and Poor Connections n Wiring Systems | Go to Step 3 |
| 3 | Do the high beam headlamps operate properly? | Go to Step 4 | Go to Headlamps Inoperative - High Beams |
| 4 | Is the DRL always in the daylight mode (low beam headlights ON at reduced intensity)? | Go to Step 12 | Go to Step 5 |
| 5 |
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Go to Step 15 | Go to Step 6 |
| 6 |
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Go to Step 7 | Go to Step 21 |
| 7 | Using a test lamp connected to ground, probe the DRL control module harness connector C2 ignition 1 voltage circuit. Does the test lamp illuminate? | Go to Step 8 | Go to Step 21 |
| 8 | Using a test lamp connected to ground, probe the DRL control module harness connector C1 battery positive voltage circuit. Does the test lamp illuminate? | Go to Step 9 | Go to Step 23 |
| 9 | Using a test lamp connected to ground probe the DRL control module harness connector C1 headlamp switch headlamps OFF signal circuit. Does the test lamp illuminate? | Go to Step 10 | Go to Step 24 |
| 10 | Using a test lamp, probe the DRL control module connector C2 between the battery positive voltage circuit and the DRL ground circuit. Does the test lamp illuminate? | Go to Step 11 | Go to Step 25 |
| 11 | Using a test lamp, probe the DRL control module harness connector C1 between the battery positive voltage circuit and the DRL low beam supply voltage circuit. Does the test lamp illuminate? | Go to Step 17 | Go to Step 20 |
| 12 | Disconnect the DRL ambient light sensor. Does the DRL change modes? | Go to Step 19 | Go to Step 13 |
| 13 | Test for a short to ground in the DRL ambient light sensor signal circuit. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | Go to Step 29 | Go to Step 14 |
| 14 | Test for a short to ground in the ambient light sensor low reference circuit. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? Did you find and correct the condition? | Go to Step 29 | Go to Step 15 |
| 15 | Test for a poor connection or an open in the DRL ambient light sensor signal circuit. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? Did you find and correct the condition? | Go to Step 29 | Go to Step 16 |
| 16 | Test for a poor connection or an open in the DRL ambient light sensor low reference circuit. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | Go to Step 29 | Go to Step 17 |
| 17 | Test for a poor connection an open in the headlamp switch supply voltage circuit for the DRL control module. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | Go to Step 29 | Go to Step 18 |
| 18 | Inspect for a poor connection at the harness connector of the DRL control module. Refer to Testing for Intermittent and Poor Connections and Connector Repairs in Wiring Systems. Did you find and correct the condition? | Step 29 | Go to Step 27 |
| 19 | Inspect for a poor connection at the harness connector of the ambient light sensor. Refer to Testing for Intermittent and Poor Connections and Connector Repairs in Wiring Systems. Did you find and correct the condition? Did you find and correct the condition? | Go to Step 29 | Go to Step 28 |
| 20 | Inspect for a open or high resistance in the DRL headlamp supply voltage circuit. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? Did you find and correct the condition? | Go to Step 29 | Go to Step 26 |
| 21 | Repair a open, high resistance, or a short to ground in the ignition 3 voltage circuit. Refer to Circuit Testing and to Wiring Repairs in Wiring Systems. Did you complete the repair? | Go to Step 29 | -- |
| 22 | Repair a open, high resistance, or a short to ground in the ignition 1 voltage circuit. Refer to Circuit Testing and to Wiring Repairs in Wiring Systems. Did you complete the repair? Did you complete the repair? | Go to Step 29 | -- |
| 23 | Repair a open, high resistance, or a short to ground in the park lamp fused battery positive voltage circuit. Refer to Circuit Testing and to Wiring Repairs in Wiring Systems. Did you complete the repair? Did you complete the repair? | Go to Step 29 | -- |
| 24 | Repair a open, high resistance, or a short to ground in the headlamp switch headlamps OFF signal circuit. Refer to Circuit Testing and to Wiring Repairs in Wiring Systems. Did you complete the repair? | Go to Step 29 | -- |
| 25 | Repair a open, high resistance, or a short battery positive voltage in the ground circuit. repair? Refer to Circuit Testing and to Wiring Repairs in Wiring Systems. Did you complete the repair? | Go to Step 29 | -- |
| 26 | Replace the DRL diode. Refer to Splicing Inline Harness Diodes in Wiring Systems. Did you complete the replacement? | Go to Step 29 | -- |
| 27 | Replace the DRL control module. Refer to Daytime Running Lights (DRL) Control Module Replacement Did you complete the replacement? | Go to Step 29 | -- |
| 28 | Replace the DRL ambient light sensor. Refer to Daytime Running Lamps (DRL) Ambient Light Sensor Replacement Did you complete the replacement? | Go to Step 29 | -- |
| 29 | Operate the system in order to verify the repair. Did you correct the condition? | System OK | Go to Step 2 |
Additional Information provided courtesy of AllDATA
