Step
| Action
| Value(s)
| Yes
| No
|
1
| Did you perform the Headlight Diagnostic System Check?
| --
| Go to
Step 2
| Go to
Headlight System Check
|
2
|
- Disconnect the BCM connector C1.
- Turn the twilight sentinel switch to the ON position.
- Use a DMM in order to measure the resistance between terminal A7
of the BCM connector C1 and a known good ground.
Is the measured resistance less than the specified value?
| 5 ohms
| Go to
Step 4
| Go to
Step 3
|
3
|
- Locate an open or a high resistance in CKT AB810.
- Repair the open or the high resistance in CKT AB810.
- If CKT AB810 is OK, replace the headlamp switch. Refer
to
Headlamp Switch Replacement
in Instrument Panel, Gauges and Console.
Did you complete the repair?
| --
| Go to
Step
14
| --
|
4
|
- Disconnect the headlamp automatic control ambient light sensor
connector.
- Use the DMM in order to measure the voltage between terminal 1
of the headlamp automatic control ambient light sensor connector and known
good ground.
Is the measured voltage equa to the specified value?
| +5 V
| Go to
Step 6
| Go to
Step 5
|
5
|
- Locate an open or a high resistance in CKT X812.
- Repair the open or the high resistance in CKT X812.
- If CKT X812 is OK, replace the heater and A/C control.
Refer to
Control Assembly Replacement
in HVAC Systems.
Did you complete the repair?
| --
| Go to
Step
14
| --
|
6
|
- Disconnect the heater and the A/C control connector C1.
- Use the DMM in order to measure the resistance between terminal 3
of the headlamp automatic control ambient light sensor and terminal 2
of the heater and A/C control connector C1.
Is the measured resistance less than the specified value?
| 5 ohms
| Go to
Step 8
| Go to
Step 7
|
7
|
- Locate an open or a high resistance in CKT F830.
- Repair the open or the high resistance in CKT F830.
Did you complete the repair?
| --
| Go to
Step
14
| --
|
8
|
- Install the scan tool.
- Proceed to BCM inputs.
- Select outside status.
The status is determined by the input to terminal A1 of the BCM
connector C1. If the input is approximately B+, the status should be
daytime. If the input is approximately O V, the status should be night time.
Does the scan tool tell you that it is either daytime or nighttime?
| --
| Go to
Step 13
| Go to
Step 9
|
9
|
- Disconnect the headlamp automatic control ambient light sensor
connector.
- Disconnect the BCM connector C1.
- Connect a fused jumper between terminals 1 and 3 of the
headlamp automatic control ambient light sensor connector.
- Use the DMM in order to measure the voltage between terminal A1
of the BCM connector C1 and a known good ground.
Is the measured voltage equal to the specified value?
| 0 V
| Go to
Step 11
| Go to
Step
10
|
10
|
- Locate a short to B+ in circuits XP830 and/or XP33.
- Repair the short to B+ in circuits XP830 and/or XP33.
- If these circuits are OK, replace the heater and the A/C control.
Refer to
Control Assembly Replacement
in HVAC Systems.
Did you complete the repair?
| --
| Go to
Step
14
| --
|
11
|
- Remove the jumper from the headlamp automatic control ambient
light sensor connector.
- Use the DMM in order to measure the voltage between terminal A1
of the BCM connector C1 and a known good ground.
Is the measured voltage equal to the specified value?
| +12 V
| Go to
Step 13
| Go to
Step 12
|
12
|
- Locate a short to ground, an open or a high resistance in circuits XP830
and/or XP33.
- Repair the short to ground, open or the high resistance in circuits XP830
and/or XP33.
- If these circuits are OK, replace the heater and the A/C control.
Refer to
Control Assembly Replacement
in Instrument Panel, Gauges and Console.
Did you complete the repair?
| --
| Go to
Step
14
| --
|
13
| Replace the BCM. Refer to
Body Control Module Replacement
in Body Control System.
Did you complete the repair?
| --
| Go to
Step
14
| --
|
14
|
- Connect all connectors and components that were previously disconnected.
- Verify that the twilight sentinel system operates properly.
Does the twilight sentinel system operate properly?
| --
| Go to
Headlight System Check
| Go to
Step 1
|
