Chevrolet Silverado / GMC Sierra. Service manual — part 2966

Circuit/System Description

The driver and passenger door lock and side window switches are integrated control module
switch assemblies. When a power window switch is activated in the up or down positions the
driver door switch (DDS) supplies power and ground to the window motor control circuits to
drive the window motor in the required direction. Prior to activating a power window motor the
DDS will supply the control circuit with a low current bias voltage in order to determine that a
short to ground condition does not exist and during window motor operation the DDS continues
to monitor the motor current to verify proper window motor operation.

Reference Information

Power Window Switch Right
Rear Down Signal

B3823 00

B3823 00

B3823 00

-

Power Window Switch Right
Rear Up Signal

B3822 00

B3822 00

B3822 00

-

Power Window Switch Left
Rear Down Signal

B3820 00

B3820 00

B3820 00

-

Power Window Switch Left
Rear Up Signal

B3819 00

B3819 00

B3819 00

-

Power Window Lockout Left
Rear Control

B3821 00

B3821 00

B3821 00

-

Power Window Lockout Right
Rear Control

B3824 00

B3824 00

B3824 00

-

LR Window Motor Control

3

3

3

-

Passenger Window Motor
Control

B3205 00

B3205 0B

B3205 00

-

RR Window Motor Control

4

4

4

-

Driver Window Motor
Control

B3205 00

B3205 0B

B3205 00

-

LR Window Switch Ground

-

3

3

-

RR Window Switch Ground

-

4

4

-

Driver Door Switch Ground

-

U0199 00

1

-

Passenger Door Switch
Ground

-

U0200 00

2

-

1. Driver Window Malfunction
2. Passenger Window Malfunction
3. Left Rear Window Malfunction
4. Right Rear Window Malfunction

2008 Chevrolet Silverado 1500

2008 ACCESSORIES & EQUIPMENT Fixed and Moveable Windows - Cab & Chassis Sierra, Cab & Chassis Silverado,

Sierra & Silverado

Schematic Reference

Moveable Window Schematics

Door Control Module Schematics

Connector End View Reference

Component Connector End Views

Description and Operation

Power Windows 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

1. Ignition ON, observe the operation of the power windows while commanding each window

UP and DOWN by using their respective window switches, each window should perform
the UP and DOWN function.

If the driver window is inoperative, refer to Driver Window Malfunction.

If the front passenger window is inoperative, refer to Passenger Window Malfunction.

If either rear passenger power window is inoperative, refer to Rear Passenger Window
Malfunction.

2. Observe the scan tool Driver RF Window Switch, Driver LR Window Switch and Driver

RR Window Switch parameters while using the driver master control switches. The
parameter should change between Off/Up/Down/Express Down.

If the parameter does not change, replace the DDS.

3. Observe the scan tool Window Lockout Switch parameter while pressing and depressing the

window lockout switch on the driver master control. The parameter should change between

2008 Chevrolet Silverado 1500

2008 ACCESSORIES & EQUIPMENT Fixed and Moveable Windows - Cab & Chassis Sierra, Cab & Chassis Silverado,

Sierra & Silverado

On and Off.

If the parameter does not change, replace the DDS.

Circuit/System Testing

Driver Power Window Inoperative

1. Ignition OFF, disconnect the X1 harness connector at the DDS.

2. Test for less than 15 ohms between the ground circuit terminal 6 and ground.

If greater than the specified range, test the ground circuit for an open/high resistance.

3. Ignition ON, verify that a test lamp illuminates between the B+ circuit terminal 2 and

ground.

If the test lamp does not illuminate, test the B+ circuit for a short to ground or an
open/high resistance.

4. Ignition OFF, connect the harness connector at the DDS.

5. Ignition ON, observe the scan tool Driver LF Window Switch parameters while using the

driver power window switch. The reading should change between Off/Up/Down/Express
Down.

If the parameter does not change, replace the DDS.

6. Ignition OFF, disconnect the harness connector at the driver window motor.

7. Connect a test lamp between control circuit terminal A and control circuit terminal B.

8. Ignition ON, command the driver window UP and DOWN by using the driver window

switch. The test lamp should illuminate when commanding the UP and DOWN states.

If the test lamp is always OFF during either of the commands, test either control circuit
for a short to ground or open/high resistance. If the circuits test normal, replace the
DDS.

If the test lamp is always ON, test either control circuit for a short to voltage. If the
circuits test normal, replace the DDS

9. If all circuits test normal, test or replace the driver window motor.

Passenger Power Window Inoperative

1. Ignition OFF, disconnect the X1 harness connector at the PDS.

2. Test for less than 1 ohm between the ground circuit terminal 6 and ground.

If greater than the specified range, test the ground circuit for an open/high resistance.

3. Ignition ON, verify that a test lamp illuminates between the B+ circuit terminal 2 and

ground.

2008 Chevrolet Silverado 1500

2008 ACCESSORIES & EQUIPMENT Fixed and Moveable Windows - Cab & Chassis Sierra, Cab & Chassis Silverado,

Sierra & Silverado

If the test lamp does not illuminate, test the B+ circuit for a short to ground or an
open/high resistance.

4. Ignition OFF, reconnect the harness connector at the PDS.

5. Ignition ON, observe the scan tool Passenger Window Switch parameters while using the

passenger power window switch. The reading should change between
Off/Up/Down/Express Down.

If the parameter does not change, replace the PDS.

6. Ignition OFF, disconnect the harness connector at the passenger window motor.

7. Test for less than 1 ohm between the control circuit terminal A and ground

If greater than the specified range, test the control circuit for a short to voltage or an
open/high resistance. If the circuit tests normal, replace the PDS.

8. Test for less than 1 ohm between the control circuit terminal B and ground

If greater than the specified range, test the control circuit for a short to voltage or an
open/high resistance. If the circuit tests normal, replace the PDS.

9. Connect a test lamp between control circuit termina A and control circuit terminal B.

10. Ignition ON, command the passenger window UP and DOWN by using the passenger

window switch. The test lamp should illuminate when commanding the UP and DOWN
states.

If the test lamp is always OFF during either of the commands, test either control circuit
for a short to ground. If the circuits test normal, replace the PDS.

11. If all circuits test normal, test or replace the passenger window motor.

Rear Power Window Inoperative

1. Ignition OFF, disconnect the harness connector at the appropriate rear window switch.

2. Test for less than 1 ohm between the ground circuit terminal F and ground.

If greater than the specified range, test the ground circuit for an open/high resistance.

3. Ignition ON, verify that a test lamp illuminates between the B+ circuit terminal G and

ground.

If the test lamp does not illuminate, test the B+ circuit for a short to ground or an
open/high resistance.

4. Enable the rear windows by using the window lockout switch.

5. Test for more than 10 volts on the control circuit terminal D.

If less than the specified range, test the control circuit for a short to ground or
open/high resistance. If the circuit tests normal, replace the BCM.

2008 Chevrolet Silverado 1500

2008 ACCESSORIES & EQUIPMENT Fixed and Moveable Windows - Cab & Chassis Sierra, Cab & Chassis Silverado,

Sierra & Silverado