Diagnostic Instructions
| • | 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. |
DTC Descriptor
DTC B2625 00 : Passenger Compartment Dimming Request Signal Circuit Voltage Below ThresholdDiagnostic Fault Information
Circuit | Short to Ground | Open/High Resistance | Short to Voltage | Signal Performance |
|---|---|---|---|---|
Body Control Module (BCM) 1 Fuse B+ Supply | B1395 03 | B1395 03 | -- | -- |
I/P Dimmer Switch Signal | B1395 03 | 1 | 1 | -- |
I/P Lamps Dimmer Switch Signal | B2652 00 | 1 | 1 | -- |
I/P Dimming Voltage Reference | B1395 03 | B2652 00 | B1395 07 | -- |
Indicator Dimming Control | B2625 00 | 1 | 1 | -- |
LED Backlight Dimming Control | B2610 00 | 1 | 1 | -- |
I/P Dimmer Switch Low Reference | -- | 1 | -- | -- |
I/P Dimmer Switch Ground | -- | 1 | -- | -- |
1. Interior Backlighting Malfunction | ||||
Circuit/System Description
The instrument panel (I/P) dimmer switch is used to increase and decrease the brightness of the interior backlighting components. The I/P dimmer switch provides a voltage signal that will increase as the brightness of the light are increased and decrease as the brightness of the lights are decreased. The body control module (BCM) provides a low reference signal and a B+ voltage reference to the I/P dimmer switch. When the I/P dimmer switch is placed in the desired position, the dimmed voltage setting is applied from the I/P dimmer switch through the I/P dimmer switch signal circuit to the BCM. The BCM interprets the signal and applies the dimmed voltage to the I/P lamps supply voltage circuit and the interior backlighting components dim to the requested level. For more detailed information concerning interior lamp operation refer to Interior Lighting Systems Description and Operation .
Conditions for Running the DTC
Battery voltage must be between 9-16 volts.
Conditions for Setting the DTC
DTC B2625 00 will set when the BCM detects a short to ground in the indicator dimming control circuit.
Actions Taken When the DTC Sets
When DTC B2625 00 is present, the BCM will not illuminate the orange HVAC fan speed or rear defogger indicators.
Conditions for Clearing the DTC
| • | The condition responsible for setting the DTC no longer exists. |
| • | You issue a scan tool CLEAR DTCs command. |
| • | A history DTC will clear once 100 consecutive malfunction-free ignition cycles have occurred. |
Reference Information
Schematic Reference
Interior Lights Dimming Schematics
Connector End View Reference
Lighting Systems Connector End Views
Electrical Information Reference
Scan Tool Reference
Circuit/System Testing
- Ignition OFF, disconnect the C3 harness connector at the HVAC control module.
- Verify with a scan tool that DTC B2625 00 does not set as current.
- Ignition OFF, reconnect the C3 harness connector at the HVAC control module and verify with a scan tool that DTC B2625 00 does not set as current.
- If all circuits test normal, replace the BCM.
| ⇒ | If DTC B2625 00 sets as current, test the indicator dimming control circuit for a short to ground. If the circuit tests normal, replace the BCM. |
| ⇒ | If DTC B2625 00 sets as current, replace the HVAC control module. |
Repair Instructions
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
Control Module References for BCM or HVAC control module replacement, setup, and programming
