GM Service Manual Online
For 1990-2009 cars only

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 provide an overview of each diagnostic category.

DTC Descriptors

DTC B320A 39:  Front Door Window Motor Internal Electronic Failure / Discard

DTC B320A 4B: Front Door Window Motor Calibration Not Learned

DTC B320A 42: Front Door Window Motor Calibration Data Set Not Programmed

DTC B320B 39: Rear Door Window Motor Internal Electronic Failure / Discard

DTC B320B 4B: Door Window Motor Calibration Not Learned

DTC B320B 42: Rear Door Window Motor Calibration Data Set Not Programmed

Diagnostic Fault Information

Circuit

Short to Ground

Open/High Resistance

Short to Voltage

Signal Performance

Driver Door Module B+

U0199 00

U0199 00

--

--

Driver Window Motor B+

U1511 00

U1511 00

--

B320A 4B

LR Window Motor B+

U1512 00

U1512 00

--

--

Passenger Door Module B+

U0200 00

U0200 00

--

--

Front Passenger Window Motor B+

U1511 00

U1511 00

--

B320A 4B

RR Window Motor B+

U1512 00

U1512 00

--

--

Driver Window Motor Serial Data

U1511 00

U1511 00

1

B320A 4B

Front Passenger Window Motor Serial Data

U1500 02, U1511 00

U1511 00

2

B320A 4B

LR Window Motor Serial Data

U1500 02, U1512 00

U1512 00

3

--

RR Window Motor Serial Data

U1500 02, U1512 00

U1512 00

4

--

LR Window Switch Voltage Reference

3

3

3

--

RR Window Switch Voltage Reference

4

4

4

--

Power Window Switch Left Rear Signal

3

3

3

--

Power Window Switch Right Rear Signal

4

4

4

--

Driver Door Module Ground

--

U0199 00, U0200 00

--

--

Passenger Door Module Ground

--

U0200 00

--

--

Driver Window Motor Ground

--

U0199 00, U0200 00

--

--

Front Passenger Window Motor Ground

--

U1511 00

--

B320A 4B

LR Window Motor Ground

--

U1512 00

--

B320A 42

RR Window Motor Ground

--

U1512 00

--

B320A 42

1. Driver Window Malfunction

2. Passenger Window Malfunction

3. Left Rear Window Malfunction

4. Right Rear Window Malfunction

Circuit/System Description

The front and rear power windows are controlled by the driver door module (DDM) and front passenger door module (PDM). The DDM and PDM each contain power window switches that are integrated into the module. The DDM contains the master power window switch that controls all power window operations. The DDM supplies the left rear power window switch with a 12 volt reference and signal circuit. The power window switch contained in the PDM controls the front passenger window operation only. The PDM supplies the right rear power window switch with a 12 volt reference and signal circuit.

When the driver power window switch is activated to a desired position, the DDM examines the request and checks for messages from other vehicle control modules prohibiting window movement. If no prohibitive messages have been received, the DDM will send a serial data message to the driver door window motor to move the window to the desired position.

When the DDM receives a request to operate one of the right side passenger windows from the master switch, a serial data message is sent to the PDM. The PDM examines the request and checks for messages from other vehicle control modules prohibiting the window movement. If no prohibitive messages have been received, the PDM will send a serial data message to the appropriate window motor to move the window as requested.

The DDM and PDM supply there respective rear power window switches with a 12 volt reference and signal circuit. The rear power window switches contain separate resistors for each switch position. When a rear power window switch is activated, the associated door control module interprets the signal and checks for messages from other vehicle control modules prohibiting the window movement. If no prohibitive messages have been received, the door control module sends a serial data message to the appropriate power window motor commanding the requested window position.

Conditions for Running the DTC

Battery voltage must be between 9-16 volts.

Conditions for Setting the DTC

B320A 39, B320B 39

An internal malfunction or a momentary voltage spike has been detected by the DDM or PDM in the front power window motor while commanding the window UP/DOWN.

B320A 42, B320B 42

A not normalized/programmed driver or front passenger door power window motor.

B320A 4B, B320B 4B

The front window motor experiences a loss of voltage in the B+ circuit or an open/high resistance in the serial data circuit.

Action Taken When the DTC Sets

The appropriate power window malfunction

Conditions for Clearing the DTC

B320A 39, B320B 39

If the DTC is current, the appropriate window motor must be replaced before the DTC can be cleared.

B320A 42, B320B 42

The affected power window motor must be programmed before the DTC can be cleared.

B320A 4B, B320B 4B

The affected power window motor must be calibrated before the DTC can be cleared.

Reference Information

Schematic Reference

Moveable Window 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

Ignition ON, command appropriate power window DOWN and UP with a scan tool. The power window should perform the DOWN and UP function as commanded.

Circuit/System Testing

B320A 39 or B320B 39

Ignition ON, command the appropriate power window DOWN and UP with a scan tool. The power window should go DOWN and UP as commanded.

If the DTC is current and the power window is inoperative, replace the power window motor.
If the DTC is history and the power window performs the UP and DOWN functions, clear the DTC.

B320A 42 or B320B 42

Ignition ON, reprogram the appropriate power window and operate the power window within the conditions for running the DTC, verify the DTC does not reset.

If the DTC resets, replace the power window motor.

B320A 4B or B320B 4B

Ignition ON, command the appropriate power window motor fully DOWN by pressing and holding the window switch for 5 seconds, then command the power window motor fully UP by lifting and holding the window switch for 5 seconds. Operate the power window within the conditions for running the DTC, verify the DTC does not reset

If the DTC resets, replace the power window motor.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

    •  Front Side Door Window Regulator Replacement
    •  Rear Side Door Window Regulator Replacement
    •  Control Module References for power window motor replacement, setup and programming