Group 2 Seat Motors Circuit Shorted
Table of contents
B3921 SATURN Possible Causes
- Faulty Seat, Lumbar, or Adjustable Pedal Motors
- Seat, Lumbar, or Adjustable Pedal Motors harness is open or shorted
- Seat, Lumbar, or Adjustable Pedal Motors circuit poor electrical connection
How do I fix code B3921 SATURN?
Check the “Possible Causes” listed above. Visually inspect the related wiring harness and connectors. Check for damaged components and look for broken, bent, pushed out, or corroded connector’s pins.
Tech Notes
- B3921 01 Group 2 Seat Motors Circuit Shorted to Battery or Open
- B3921 02 Group 2 Seat Motors Circuit Shorted to Ground
Cost of diagnosing the B3921 SATURN code
The cost of diagnosing the B3921 SATURN code is 1.0 hour of labor. The auto repair labor rates vary by location, your vehicle’s make and model, and even your engine type. Most auto repairs shops charge between $75 and $150 per hour.
Possible Symptoms
- Engine Light ON (or Service Engine Soon Warning Light)
B3921 SATURN Description
The Seat Memory Control Module controls the seat, lumbar, and adjustable pedal motors via half bridges that are connected to power rails internal to the module. The Seat Memory Control Module connects all of the motor control circuits on each power rail to a common reference point whenever they are not in operation. The module monitors all seat motor control circuits for a shorted to ground or voltage before enabling any seat motor.
When a power seat, lumbar, or adjustable pedal switch is pressed or when a memory recall is requested, each seat motor receives battery voltage and ground from the seat memory control module via the motor control circuits. All motors are reversible, so the direction the motor rotates depends on which control circuit voltage is applied and which control circuit ground is applied. When the switch is operated in the opposite direction, the module reverses the polarity and applies voltage and ground to the opposite circuits to move the seat in the opposite direction.
The Diagnostic Trouble Code (DTC) sets when the voltage on any power rail 2 motor control circuit exceeds 2.78 volts for 100 ms or is below 1.47 volts for 100 ms.