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 08 : Passenger Compartment Dimming Request Signal Circuit Signal InvalidDiagnostic Fault Information
Circuit | Short to Ground | Open/High Resistance | Short to Voltage | Signal Performance |
|---|---|---|---|---|
Instrument Panel Lamp Fuse B+ | 2 | 2 | 2 | -- |
I/P Dimmer Switch Signal | B3600 08 | B3600 08 | B3600 08 | -- |
Backlight Lamp Control | 2 | 2 | 2 | -- |
LED Backlight Dimming Control | 3 | 3 | 3 | -- |
I/P Dimmer Switch Low Reference | -- | 1 | -- | -- |
I/P Dimmer Switch Ground | -- | 2 | -- | -- |
1. Dimmer Switch Malfunction 2. Interior Backlighting Malfunction -- Incandescent 3. Interior Backlighting Malfunction -- LED | ||||
Circuit/System Description
The instrument panel module (IPM) provides the instrument panel (I/P) dimmer switch with a 5-volt reference voltage and ground. The I/P dimmer switch is a potentiometer that varies the input signal voltage to the IPM. This input determines the intensity level of the back lighting illumination. When the IPM receives the input from the I/P dimmer switch, the IPM will send a serial data message to all control modules that have lamps capable of being dimmed, indicating the ON/OFF status and intensity level of the back lighting. The IPM will default to full intensity if the input from the I/P dimmer switch is not within the specified values.
Conditions for Running the DTC
Battery voltage must be between 9-16 volts.
Conditions for Setting the DTC
The IPM detects a short to ground, short to voltage, or an open/high resistance in the I/P lamp dimmer switch signal circuit after 450 milliseconds.
Action Taken When the DTC Sets
The IPM will default to full intensity if the input from the I/P dimmer switch is not within the specified values.
Conditions for Clearing the DTC
| • | The condition responsible for setting the DTC no longer exists. |
| • | A history DTC will clear once 50 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
- Ignition OFF, disconnect the harness connector at the I/P Dimmer switch.
- Ignition OFF, verify that a test lamp illuminates between B+ and the low reference circuit terminal 1.
- Ignition ON, verify the scan tool Dimming POT A/D parameter is greater than 140 counts.
- Install a 3-A fused jumper wire between the signal circuit terminal 2 and the low reference circuit terminal 1. Verify the scan tool Dimming POT A/D parameter is less than 30 counts.
- If all circuits test normal, test or replace the I/P dimmer switch.
| ⇒ | If the test lamp does not illuminate, test the low reference circuit for an open/high resistance. |
| ⇒ | If less than the specified range, test the signal circuit terminal 2 for a short to ground. If the circuit tests normal, replace the IPM. |
| ⇒ | If greater than the specified range, test the signal circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the IPM. |
Repair Instructions
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
| • | Control Module References for IPM replacement, setup, and programming |
