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 B3600 03 : 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+ | B1395 03 | B1395 03 | -- | -- |
Body Control Module (BCM) 7 Fuse B+ | B2652 00 | B2652 00 | -- | -- |
I/P Dimming Voltage Reference | B1395 03 | B2652 00 | B1395 07 | -- |
I/P Dimmer Switch Signal | B1395 03 | 1 | 1 | -- |
I/P Lamps Dimmer Switch Signal | B2652 00 | 1 | 1 | -- |
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.
Conditions for Running the DTC
Battery voltage must be between 9-16 volts.
Conditions for Setting the DTC
DTC B3600 03 will set when the BCM detects a short to ground or an open/high resistance in the I/P dimmer switch signal circuit.
Actions Taken When the DTC Sets
| • | The I/P dimmer switch will not operate. |
| • | The I/P dimming lamps will not illuminate. |
Conditions for Clearing the DTC
| • | The condition responsible for setting the DTC no longer exists. |
| • | 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
Description and Operation
Interior Lighting Systems Description and Operation
Electrical Information Reference
Scan Tool Reference
Control Module References for scan tool information
Circuit/System Testing
- With a scan tool clear the DTC.
- Ignition OFF, disconnect the harness connector at the dimmer switch.
- Ignition OFF, verify that a test lamp illuminates between B+ and the ground circuit terminal 10.
- Verify the scan tool Dimming Control Signal parameter is less than 0.2 volts.
- Install a 3-A fused jumper wire between the signal circuit terminal 9 and the B+ voltage reference circuit terminal 5. Verify the scan tool Dimming Control Signal parameter is greater than 3.5 volts.
- If all circuits test normal, test or replace the dimmer switch.
| ⇒ | If the test lamp does not illuminate, test the ground circuit for an open/high resistance. |
| ⇒ | If greater than the specified range, test the signal circuit for a short to voltage. If the circuit tests normal, replace the BCM. |
| ⇒ | If less than the specified range, test the signal circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the BCM. |
Repair Instructions
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
| • | Control Module References for BCM replacement, setup, and programming |
