Dimming Level Switch Input Circuit High

Monitored & Set Condition

1. When Monitored: With ignition On.
2. Set Condition: The BCM detects a voltage greater than 4.75-volts on the dimming level switch input for more than 5 seconds.

Possible Causes:

• Intermittent Conditions
• Panel Lamps Dimmer Switch MUX Open
• Short To Battery
• Multifunction Switch
• Body Control Module

Testing

1. Turn the ignition on. With the DRBIII(R), clear all BCM DTC's. Actuate the Dimming Level Switch. With the DRBIII(R), read the DTC information. Does the DRBIII(R) read: Dimming Level Switch Input CKT High? If yes, go to next step. If no, the condition that caused the symptom is currently not present. Inspect the related wiring for a possible intermittent condition. Look for any chafed, pierced, pinched, or partially broken wires. Perform BODY VERIFICATION TEST  .
2. Turn the ignition off. Disconnect the BCM C2 harness connector. Turn the ignition on to check the Courtesy Lamp operation. Did the Courtesy Lamps come on? If yes, go to next step. If no, repair the Panel Lamps Dimmer Switch MUX circuit for an open condition. Perform BODY VERIFICATION TEST  .
3. Ensure the Junction Block C24 harness connector on the front of the junction block is connected. Turn on all overhead, map and rear reading 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? If yes, repair the short to battery condition. Perform BODY VERIFICATION TEST  . If no, go to next step.
4. 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 there any voltage on the Courtesy Lamps Driver Circuit? If yes, replace the Multifunction Switch. Perform BODY VERIFICATION TEST  . If no, replace the Body Control Module. Perform BODY VERIFICATION TEST  .