B3600
DTC B3600
Circuit 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 GMLAN 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. For more detailed information concerning interior lighting operation, Refer to Interior Lighting Systems Description and Operation.
DTC Descriptor
This diagnostic procedure supports the following DTC:
DTC B3600 Passenger Compartment Dimming Request Signal Circuit
This vehicle has DTCs which include DTC Symptoms. For more information on DTC Symptoms,
Conditions for Running the DTC
* The IPM must be powered.
* The IPM performs this diagnostic test mode every 150 milliseconds.
Conditions for Setting the DTC
The IPM detects an open, short to ground, or short to voltage 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.
* You issue a scan tool CLEAR DTCs command.
* A history DTC will clear once 50 consecutive malfunction-free ignition cycles have occurred.
Diagnostic Aids
Thoroughly inspect the wiring and connectors. An incomplete inspection of the wiring and connectors may result in misdiagnosis causing part replacement with the reappearance of the malfunction. If an intermittent malfunction exists, Refer to Testing for Intermittent Conditions and Poor Connections. Component Tests and General Diagnostics
Test
