• | 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 instrument panel lamps dimmer switch is activated, a variable voltage signal is applied through the LED dimmer switch signal circuit to the body control module (BCM). The BCM then applies a message on the low speed GMLAN serial data communication circuit to the door switches to illuminate the switch backlighting. The BCM, driver door switch, and passenger door switch then applies a variable voltage signal through the LED dimming supply circuit to the components on that circuit.
• | Battery Voltage be between 9-16 volts. |
• | The ignition is ON. |
The BCM, driver door switch, and passenger door switch detects a short to voltage, short to ground, or an open on the LED dimming supply circuit.
The BCM, driver door switch, and passenger door switch will cease attempts to dim or illuminate the LED 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
• | Left steering wheel switch terminal 8 |
• | Right steering wheel switch terminal 1 |
• | Multifunction accessory switch terminal 1 |
• | Analog clock terminal 2 |
• | DIC switch terminal 5 |
⇒ | If the test lamp does not illuminate, test the ground circuit for an open/high resistance. |
• | Left steering wheel switch terminal 6 |
• | Right steering wheel switch terminal 2 |
• | Multifunction accessory switch terminal 4 |
• | Analog clock terminal 3 |
• | DIC switch terminal 4 |
• | Radio terminal 8 X1 |
⇒ | 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, driver door switch, and passenger door switch replacement, setup, and programming |