B3600
DTC B3600
Diagnostic Instructions
* Perform the Diagnostic System Check - Vehicle (Diagnostic System Check - Vehicle) prior to using this diagnostic procedure.
* Review Strategy Based Diagnosis (Strategy Based Diagnosis) for an overview of the diagnostic approach.
* Diagnostic Procedure Instructions (Diagnostic Procedure Instructions) provides an overview of each diagnostic category.
DTC Descriptors
DTC B3600 03
- Passenger Compartment Dimming Request Signal Circuit Low Voltage
DTC B3600 07
- Passenger Compartment Dimming Request Signal Circuit High Voltage
Diagnostic Fault Information
Circuit/System Description
The instrument panel lamp dimmer switch is used to increase and decrease the brightness of the interior backlighting components. The instrument panel dimmer switch provides a voltage signal that will increase as the brightness of the lights are increased and decrease as the brightness of the lights are decreased. The body control module (BCM) provides a low reference circuit, signal circuit, and a B+ voltage reference circuit to the instrument panel dimmer switch. When the instrument panel dimmer switch is placed in the desired position, the dimmed voltage setting is applied from the instrument panel dimmer switch through the instrument panel dimmer switch signal circuit to the BCM. The BCM interprets the signal and applies the dimmed voltage to the instrument panel 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 V.
Conditions for Setting the DTC
B3600 03
The BCM detects a short to ground or an open/high resistance on the instrument panel dimmer switch signal circuit.
B3600 07
The BCM detects a short to voltage on the instrument panel dimmer switch signal circuit.
Actions Taken When the DTC Sets
The instrument panel dimmer switch will not operate. After a 3 second delay, the instrument panel dimming lamps will light at 50% intensity.
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 (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 (Circuit Testing)
* Connector Repairs (Connector Repairs)
* Testing for Intermittent Conditions and Poor Connections (Testing for Intermittent Conditions and Poor Connections)
* Wiring Repairs (Wiring Repairs)
Scan Tool Reference
Control Module References (Programming and Relearning) for scan tool information
Circuit/System Testing
1. Ignition OFF, disconnect the harness connector at the S36 instrument panel dimmer switch.
2. Ignition OFF, test for less than 60 ohm between the low reference circuit terminal 10 and ground.
• If greater than the specified range, test the low reference circuit for an open/high resistance. If the circuit tests normal, replace the K9 BCM.
3. Ignition ON, test for B+ between the B+ circuit terminal 5 and ground.
• If less than the specified range, test the B+ circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the K9 BCM.
Note: The BCM will automatically put in a default Incandescent Dimming Duty Cycle Command setting of 50%. The next step will look for a brief change in the Incandescent Dimming Duty Cycle Command parameter from 50% to 5% - returning after 3 seconds to the 50% default setting.
4. Install a 3 A fused jumper wire between the signal circuit terminal 9 and the B+ circuit terminal 5. Verify the scan tool Incandescent Dimming Duty Cycle Command briefly drops to 5%, returning after 3 seconds to the 50% default value.
• If less than the specified range, test the signal circuit for short to ground or an open/high resistance. If the circuit tests normal, replace the K9 BCM.
5. If all circuits test normal, test or replace the S36 instrument panel dimmer switch.
Repair Instructions
Perform the Diagnostic Repair Verification (Verification Tests) after completing the diagnostic procedure.
* Instrument Panel Lamp Dimmer Switch Replacement (Service and Repair)
* Control Module References (Programming and Relearning) for BCM replacement, programming and setup