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 provides an overview of each diagnostic category.

DTC Descriptors

DTC B3821 00: Left Rear Window Relay Power Circuit

DTC B3824 00: Right Rear Window Relay Power Circuit

Diagnostic Fault Information

Circuit

Short to Ground

Open/High Resistance

Short to Voltage

Signal Performance

Driver Door Module B+

U0199 00

U0199 00

--

--

LR Window Switch B+

1, 3

3

--

--

Front Passenger Door Module B+

U0200 00

U0200 00

--

--

RR Window Switch B+

2, 4

4

--

--

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

--

RR Window Switch Ground

--

4

4

--

Driver Door Module Ground

--

U0199 00

U0199 00

--

Front Passenger Door Module Ground

--

U0200 00

U0200 00

--

1. Driver Window Malfunction

2. Passenger Window Malfunction

3. Left Rear Window Malfunction

4. Right Rear Window Malfunction

Circuit/System Description

The rear window switches continuously monitor the enable/disable signal voltage sent by the body control module (BCM) and compares the signal voltage to the B+ voltage. If the rear window lockout function is enabled, the signal is at or near B+ voltage allowing for normal rear window switch function and when disabled, the signal voltage drops by approximately 0.5 volts and the rear window switches will disable the rear window switch function. The rear windows will then only operate when the BCM receives a command to operate the appropriate rear window UP or DOWN from the driver door module (DDM).

Conditions for Running the DTC

    • Battery voltage is between 9-16 volts.
    • The ignition is ON.

Conditions for Setting the DTC

B3821 00

The BCM detects a fault in the left rear window lockout circuit.

B3824 00

The BCM detects a fault in the right rear window lockout circuit.

Action Taken When the DTC Sets

The left or right rear power window will be inoperative.

Conditions for Clearing the DTC

    • The DTC will be current for as long as the fault is present.
    • When the fault is no longer present, the DTC will be a history DTC.
    • A history DTC will clear after 50 ignition cycles

Reference Information

Schematic Reference

Moveable Window Schematics

Connector End View Reference

Window Systems 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

    •  Scan Tool Data Definitions
    •  Scan Tool Data List
    •  Scan Tool Output Controls

Circuit/System Verification

Ignition ON, command the rear passenger power windows UP and DOWN with a scan tool, the rear passenger power windows should perform the UP and DOWN function.

Circuit/System Testing

  1. Ignition OFF, disconnect the harness connector at the appropriate rear window switch.
  2. Ignition ON, test for more than 10 volts between the control circuit terminal D and ground.
  3. 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.
  4. If all circuits test normal, replace the rear window switch.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

    •  Rear Side Door Window Switch Replacement
    •  Control Module References for BCM replacement, setup and programming