Headlamps Always On - Low or High Beam
WARNING: This page is about a different car, the 2006 Pontiac Montana SV6, 2006 Chevrolet Uplander, and 2006 Buick Terraza. However, it is still accessible from the selected car via links, so may be relevant.
Headlamps Always On - Low or High Beam
| Step | Action | Yes | No |
|---|---|---|---|
| Schematic Reference: Headlights/Daytime Running Lights (DRL) Schematics Connector End View Reference: Master Electrical Component List in Wiring Systems |
|||
| 1 | Did you perform the Diagnostic System Check - Vehicle? | Go to Step 2 | Go to Diagnostic System Check - Vehicle in Vehicle DTC Information |
| 2 |
|
Go to Testing for Intermittent Conditions and Poor Connections in Wiring Systems | Go to Step 3 |
| 3 | Rotate the headlamp switch to the auto lamps OFF position and release the switch. Do the headlamps remain ON? |
Go to Step 6 | Go to Step 4 |
| 4 | Test the ambient light sensor signal and ground circuits of the ambient light sensor for an open or high resistance. Refer to Circuit Testing
and Wiring Repairs
in Wiring Systems. Did you find and correct the condition? |
Go to Step 20 | Go to Step 5 |
| 5 | Test the ambient light sensor signal circuit of the ambient light sensor for a short to voltage. Refer to Circuit Testing
and Wiring Repairs
in Wiring Systems. Did you find and correct the condition? |
Go to Step 20 | Go to Step 13 |
| 6 | Are the park lamps also illuminated? | Go to Step 9 | Go to Step 7 |
| 7 | Test the following circuits for a short to voltage:
Did you find and correct the condition? |
Go to Step 20 | Go to Step 8 |
| 8 | Test the headlamp low beam relay control circuit of the body control module (BCM) for a short to ground. Refer to Circuit Testing
and Wiring Repairs
in Wiring Systems. Did you find and correct the condition? |
Go to Step 20 | Go to Step 12 |
| 9 | Using a scan tool, observe the following parameters:
Does any parameter indicate ON? |
Go to Step 10 | Go to Step 14 |
| 10 |
|
Go to Step 15 | Go to Step 11 |
| 11 | Test the following circuits of the BCM for a short to ground as appropriate:
Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? |
Go to Step 20 | Go to Step 14 |
| 12 | Inspect for poor connections at the harness connector of the high or low beam relay. Refer to Testing for Intermittent Conditions and Poor Connections
and Connector Repairs
in Wiring Systems. Did you find and correct the condition? |
Go to Step 20 | Go to Step 16 |
| 13 | Inspect for poor connections at the harness connector of the ambient light sensor. Refer to Testing for Intermittent Conditions and Poor Connections
and Connector Repairs
in Wiring Systems. Did you find and correct the condition? |
Go to Step 20 | Go to Step 17 |
| 14 | Inspect for poor connections at the harness connector of the BCM. Refer to Testing for Intermittent Conditions and Poor Connections
and Connector Repairs
in Wiring Systems. Did you find and correct the condition? |
Go to Step 20 | Go to Step 18 |
| 15 | Inspect for poor connections at the harness connector of the headlamp or multifunction switch as appropriate. Refer to Testing for Intermittent Conditions and Poor Connections
and Connector Repairs
in Wiring Systems. Did you find and correct the condition? |
Go to Step 20 | Go to Step 19 |
| 16 | Replace the appropriate high or low beam relay. Refer to Circuit Protection - Fusible Links
in Wiring Systems. Did you complete the replacement? |
Go to Step 20 | - |
| 17 | Replace the ambient light sensor. Refer to Daytime Running Lamps (DRL) Ambient Light Sensor Replacement . Did you complete the replacement? |
Go to Step 20 | - |
| 18 | Replace the BCM. Refer to Control Module References
in Computer/Integrating Systems for replacement, setup and programming. Did you complete the replacement? |
Go to Step 20 | - |
| 19 | Replace the multifunction or headlamp switch as necessary. Refer to Multifunction, Turn Signal Switch Replacement
in Steering Wheel and Column or Headlamp Switch Replacement . Did you complete the replacement? |
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 |