DIMMING LEVEL SWITCH INPUT CIRCUIT LOW
For a complete wiring diagram Refer to Section 8W
- When Monitored:
Ignition ON.
- Set Condition:
BCM detects a voltage less than 0.25 volts on the dimming level switch input for more than 5 seconds.
| Possible Causes |
| COURTESY LAMPS DRIVER HEADLINER CIRCUIT SHORT TO GROUND |
| COURTESY LAMPS DRIVER CIRCUIT BODY HARNESS SHORT TO GROUND |
| PANEL LAMPS DIMMER SWITCH MUX SHORT TO GROUND |
| MULTIFUNCTION SWITCH |
| BODY CONTROL MODULE |
Diagnostic Test
1. INTERMITTENT CONDITIONTurn the ignition on.
With the scan tool, clear all BCM DTC's.
Actuate the Dimming Level Switch.
With the scan tool, read the DTC information.
Does the scan tool read: Dimming Level Switch Input CKT Low?
Yes
- Go To2
No
- The condition is not present at this time. Monitor scan tool parameters while wiggling the related wire harness. Refer to any Technical Service Bulletins that may apply. Visually inspect the related wiring harness and connector terminals.
- Perform BODY VERIFICATION TEST - VER 1.
2. PANEL LAMPS DIMMER SWITCH MUX OPEN
Turn the ignition off.
Disconnect the BCM C2 harness connector.
Cycle the ignition switch off than back on.
Did any of the Courtesy Lamps come on?
Yes
- Go To3
No
- Repair the Panel Lamps Dimmer Switch MUX for an open condition.
- Perform BODY VERIFICATION TEST - VER 1.
3. PANEL LAMPS DIMMER SWITCH MUX SHORT TO GROUND
Ensure the Junction Block C24 harness connector on the front of the junction block is connected.
Turn on all overhead, map and rear rearing lamps by their own individual switches.
This will disconnect each lamp from the Courtesy Lamp Driver Circuit.
Did any lamp fail to light when it was turned on by it's own switch?
Yes
- Repair the Panel Lamps Dimmer Switch MUX circuit for a short to ground condition.
- Perform BODY VERIFICATION TEST - VER 1.
No
- Go To4
4. MULTIFUNCTION SWITCH
Turn the ignition off.
Disconnect the Junction Block C24 harness connector from the front of the junction block.
Remove the Body Control Module from the junction block.
Measure the voltage of the Courtesy Lamps Driver circuit.
Is voltage present on the Courtesy Lamps Driver Circuit?
Yes
- Replace the Multifunction Switch.
- Perform BODY VERIFICATION TEST - VER 1.
No
- Replace the Body Control Module.
- Perform BODY VERIFICATION TEST - VER 1.