2010 Cadillac CTS Sedan AWD V6-3.6L Page 641
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 B3920 01
- Group 1 Seat Motors Common Circuit Short to Battery
DTC B3920 02
- Group 1 Seat Motors Common Circuit Short to Ground
DTC B3921 01
- Group 2 Seat Motors Common Circuit Short to Battery
DTC B3921 02
- Group 2 Seat Motors Common Circuit Short to Ground
Diagnostic Fault Information
Circuit/System Description
The memory seat module (MSM) controls the seat, recline, lumbar, and steering column motors via half bridges that are divided into 2 groups that
are connected to separate power rails internal to the module. The MSM connects all of the motor control circuits on each power rail to a common
reference point whenever they are not in operation. This reference point is biased to approximately 2.5 volts. The MSM checks to see if this
reference voltage is shorted to ground or battery before enabling any seat, lumbar, or steering column motor.
Conditions for Running the DTC
The MSM must be powered.
Conditions for Setting the DTC
