2010 Cadillac CTS Sedan AWD V6-3.6L Page 617
DTC B3821 or B3824
Diagnostic Instructions
* Perform the Diagnostic System Check - Vehicle (See: Testing and Inspection/Initial Inspection and Diagnostic Overview/Diagnostic System
Check - Vehicle) prior to using this diagnostic procedure.
* Review Strategy Based Diagnosis (See: Testing and Inspection/Initial Inspection and Diagnostic Overview/Strategy Based Diagnosis) for an
overview of the diagnostic approach.
* Diagnostic Procedure Instructions (See: Testing and Inspection/Initial Inspection and Diagnostic Overview/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/System Description
The body control module (BCM) monitors the window lockout command from the driver door module (DDM). When the rear window switch
operation is authorized, the BCM signal voltage drops approximately 5 volts to the rear window switches allowing for normal window operation
from the rear switches. If the rear window lockout function is commanded, the BCM signal voltage is at B+ voltage which disables the rear window
switches and the rear windows will only operate when the BCM receives a command from the driver master control.
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.
