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Chevrolet Silverado / GMC Sierra. Manual - part 2480
DTC B2652 00
Passenger Compartment Dimming 3
Diagnostic Fault Information
Circuit/System Description
The body control module (BCM) applies a 12-volt reference voltage through the headlamp and
panel dimmer switch 12-volt reference circuit to the headlamp and panel dimmer switch. When
the dimming switch is placed in the desired position, the dimmed voltage setting is applied from
the headlamp and panel dimmer switch through the instrument panel (I/P) lamp dimming switch
signal circuit to the BCM. The BCM then applies the dimmed voltage to the I/P lamp dimming
control circuit and the components on the circuit.
Conditions for Running the DTC
The ignition is ON.
Conditions for Setting the DTC
The BCM receives an open, voltage, or ground signal on the I/P lamp dimming control circuit.
Action Taken When the DTC Sets
The I/P lamps are not illuminated.
Conditions for Clearing the DTC
The conditions for setting the DTC are no longer present.
A history DTC clears after 100 malfunction-free ignition cycles.
Reference Information
Schematic Reference
Interior Lights Dimming Schematics
Circuit
Short to
Ground
Open/High
Resistance
Short to
Voltage
Signal
Performance
Instrument Panel Lamps
Dimming Control
B2652 00
B2652 00
B2652 00
-
2008 Chevrolet Silverado 1500
2008 ACCESSORIES & EQUIPMENT Lighting - Cab & Chassis Sierra, Cab & Chassis Silverado, Sierra & Silverado
Connector End View Reference
Component Connector End Views
Description and Operation
Interior Lighting Systems Description and Operation
Electrical Information Reference
Circuit Testing
Connector Repairs
Testing for Intermittent Conditions and Poor Connections
Wiring Repairs
Scan Tool Reference
Control Module References for scan tool information
Circuit/System Verification
Ignition ON and park lamps ON, vary the headlamp and panel dimmer switch from dim to full
bright. The I/P lamps should dim and then become full bright.
Circuit/System Testing
1. Ignition OFF, disconnect the harness connector at the affected component.
2. Ignition OFF, verify that a test lamp illuminates between the listed ground circuit terminal
and battery voltage.
Headlamp Switch terminal 8
Sunroof switch terminal 5
Front door lock switch w/o AN3 terminal B
Driver window switch w/o AN3 terminal A X2
Front passenger window switch w/o AN3 terminal F
OSRVM switch w/o AN3 terminal G
Transfer case shift control switch terminal 6
Roof beacon switch terminal 1
Sliding rear window switch terminal D
2008 Chevrolet Silverado 1500
2008 ACCESSORIES & EQUIPMENT Lighting - Cab & Chassis Sierra, Cab & Chassis Silverado, Sierra & Silverado
Rear window switch terminal F
If the test lamp does not illuminate, test the ground circuit for an open/high resistance.
3. Connect a test lamp between the listed backlighting control circuit terminal and ground.
Headlamp Switch terminal 7
Sunroof switch terminal 3
Front door lock switch w/o AN3 terminal A
Driver window switch w/o AN3 terminal 1 X1
Front passenger window switch w/o AN3 terminal B
OSRVM switch w/o AN3 terminal E
Transfer case shift control switch terminal 5
Roof beacon switch terminal 2
Sliding rear window switch terminal E
Rear window switch terminal B
4. Command the dimming test high to low with a scan tool. The test lamp should turn from
bright to dim when changing between the commanded states.
If the test lamp is always off, test the control circuit for an open/high resistance or
short to ground. If the circuit tests normal, replace the BCM.
If the test lamp is always bright, test the control circuit for a short to voltage. If the
circuit tests normal, replace the BCM.
5. If all circuits test normal, test or replace the affected component.
Repair Procedures
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
Refer to the appropriate replacement procedure for the component causing the condition.
Control Module References for BCM replacement, setup, and programming
DTC B3445
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
2008 Chevrolet Silverado 1500
2008 ACCESSORIES & EQUIPMENT Lighting - Cab & Chassis Sierra, Cab & Chassis Silverado, Sierra & Silverado
DTC B3445 00
Stop Lamp Circuit
Diagnostic Fault Information
Circuit/System Description
When the brake pedal is applied, the brake pedal switch normally closed contact signal circuit
voltage is interrupted to the body control module (BCM). The BCM then applies a voltage to the
stop lamp supply voltage circuit to the stop lamps.
Conditions for Running the DTC
The ignition is ON.
The stop lamps must be commanded ON.
Conditions for Setting the DTC
The BCM detects a short to ground in the stop lamp supply voltage circuit when the stop lamps
are commanded ON.
Action Taken When the DTC Sets
The stop lamps do not illuminate.
Conditions for Clearing the DTC
The conditions for setting the DTC are no longer present.
A history DTC clears after 100 malfunction-free ignition cycles.
Reference Information
Schematic Reference
Exterior Lights Schematics
Circuit
Short to
Ground
Open/High
Resistance
Short to
Voltage
Signal
Performance
Stop Lamp Supply Voltage
B3445 00
1
2
-
1. Stop Lamps Inoperative
2. Stop Lamps Always On
2008 Chevrolet Silverado 1500
2008 ACCESSORIES & EQUIPMENT Lighting - Cab & Chassis Sierra, Cab & Chassis Silverado, Sierra & Silverado
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