| • | Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure. | 
| • | Review Strategy Based Diagnosis for an overview of the diagnostic approach. | 
| • | Diagnostic Procedure Instructions provides an overview of each diagnostic category. | 
Circuit  | Short to Ground  | Open/High Resistance  | Short to Voltage  | Signal Performance  | 
|---|---|---|---|---|
I/P Dimming Voltage Reference  | B1395 03, B3600 03  | B1395 03, B2652 00, B3600 03  | B1395 07  | --  | 
Courtesy Lamp Voltage Reference  | B2615 00, B2615 02  | B2615 00, B2615 04  | B2615 00, B2615 01  | --  | 
LED Dimming Voltage Reference  | B2610 00, B2610 02  | B2610 00, B2610 04  | B2610 00, B2610 01  | --  | 
LED Indicator Dimming Volage Reference  | B2625 00  | B2625 00  | B2625 00  | --  | 
Dome Lamp Switch Signal  | 2  | 2  | 2  | --  | 
Left Front Door Open Switch Signal  | 3  | 3  | 3  | --  | 
Left Rear Door Open Switch Signal  | 4  | 4  | 4  | --  | 
Right Front Door Open Switch Signal  | 3  | 3  | 3  | --  | 
Right Rear Door Open Switch Signal  | 4  | 4  | 4  | --  | 
Stop Lamp Switch Signal  | B1395 03, B3600 03  | --  | --  | --  | 
Dome/Reading Lamp Control  | B2615 00  | B2615 00  | --  | --  | 
Dome/Reading Lamp Supply Voltage  | 1  | 1  | --  | --  | 
Exterior Lamps Illumination Supply Voltage  | 5  | 5  | 5  | --  | 
Inadvertent Power Control  | 5  | 5  | 5  | --  | 
I/P Lamps Dimming Control  | B2652 00  | B2652 00  | B2652 00  | --  | 
Dome/Reading Lamp Low Control - Driver Door  | --  | 1  | --  | --  | 
Dome/Reading Lamp Low Control - Passenger Door  | --  | 1  | --  | --  | 
Exterior Lamps Low Reference  | --  | 5  | --  | --  | 
I/P Dimmer Switch Ground  | --  | 2  | --  | --  | 
LH Vanity Mirror Courtesy Lamp Ground  | --  | 1  | --  | --  | 
Overhead Console Courtesy Lamp Ground  | --  | 1  | --  | --  | 
Rear Dome Lamp Ground  | --  | 1  | --  | --  | 
RH Vanity Mirror Courtesy Lamp Ground  | --  | 1  | --  | --  | 
1. Courtesy Lamps Malfunction 2. Dome Lamp Switch Malfunction 3. Door Open Switch Malfunction - Front 4. Door Open Switch Malfunction - Rear 5. Exterior Lamps Malfunction  | ||||
When the interior lamps dimming switch is activated, a variable voltage signal is applied through the instrument panel lamps dimmer switch signal circuit to the body control module (BCM). The BCM then applies a variable voltage signal through the LED indicator dimming supply circuit to the components on the circuit.
The ignition is ON.
The BCM receives a ground signal on the LED indicator dimming supply circuit.
The BCM cease attempt to dim or illuminate the LED indicator lamps.
| • | The conditions for setting the DTC are no longer present. | 
| • | A history DTC clears after 100 malfunction-free ignition cycles. | 
| • | The BCM receives the clear code command from the scan tool. | 
Interior Lights Dimming Schematics
Interior Lighting Systems Description and Operation
Control Module References for scan tool information
| • | IP multifunction switch X88/Z88 w/UD7/XA7 terminal 8 | 
| • | IP multifunction switch Z75 w/UD7 terminal 4 | 
| • | IP multifunction switch Z75 w/XA7 terminal 7 | 
| • | 4wd mode switch terminal 4 | 
| ⇒ | If the test lamp is always OFF, test the control circuit for an open/high resistance or short to ground. If the circuit tests normal, replace the BCM. | 
| ⇒ | If the test lamp is always bright, test the control circuit for a short to voltage. If the circuit tests normal, replace the BCM. | 
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
| • | Control Module References for BCM replacement, setup, and programming |