B3600

DTC B3600

Diagnostic Instructions

* Perform the Diagnostic System Check - Vehicle (Initial Inspection and Diagnostic Overview) prior to using this diagnostic procedure.
* Review Strategy Based Diagnosis (Initial Inspection and Diagnostic Overview) for an overview of the diagnostic approach.
* Diagnostic Procedure Instructions (Initial Inspection and Diagnostic Overview)provides an overview of each diagnostic category.



DTC Descriptor
DTC B3600 03
- Passenger Compartment Dimming Request Signal Circuit Voltage Below Threshold




Diagnostic Fault Information






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.
* 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 (Interior Lights Dimming Schematics)
Connector End View Reference

Component Connector End Views (Connector Views)
Description and Operation

Interior Lighting Systems Description and Operation (Interior Lighting Systems Description and Operation)
Electrical Information Reference

* Circuit Testing (Component Tests and General Diagnostics)
* Connector Repairs (Component Tests and General Diagnostics)
* Testing for Intermittent Conditions and Poor Connections (Component Tests and General Diagnostics)
* Wiring Repairs (Component Tests and General Diagnostics)

Scan Tool Reference

Control Module References (Programming and Relearning)


Circuit/System Testing

1. With a scan tool clear the DTC.
2. Ignition OFF, disconnect the harness connector at the I/P Dimmer switch.
3. Ignition OFF, verify that a test lamp illuminates between B+ and the ground circuit terminal 10.

• If the test lamp does not illuminate, test the ground circuit for an open/high resistance.

4. Verify the scan tool dimming control signal parameter is less than 0.2 volts.

• If greater than the specified range, test the signal circuit for a short to voltage. If the circuit tests normal, replace the BCM.

5. 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 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.

6. If all circuits test normal, test or replace the I/P dimmer switch.



Repair Instructions

Perform the Diagnostic Repair Verification (Verification Tests) after completing the diagnostic procedure.

* Instrument Panel Lamp Dimmer Switch Replacement (Left Hand Drive) (Instrument Panel Lamp Dimmer Switch Replacement (Left Hand Drive))Instrument Panel Lamp Dimmer Switch Replacement (Right Hand Drive) (Instrument Panel Lamp Dimmer Switch Replacement (Right Hand Drive))
* Control Module References (Programming and Relearning)for BCM replacement, setup, and programming