B1771: Driver Seat Motor Circuit Short to Battery
Code B1771 indicates that the Driver Seat Module (DSM) has detected a short to battery voltage (12V) in the control circuit for the seat's rearward movement motor (recline or slide). This means the signal or power wire is directly connected to 12V, preventing proper PWM control or current management by the module. As a result, the module typically disables the function to protect the electronics.
1. Commonly Affected Makes
2. Most Common Causes
- Chafed or pinched seat motor wiring shorting against the chassis or body with battery voltage
- Internal short circuit in the seat adjustment motor (windings to case or terminals)
- Failed power transistor (driver) inside the Driver Seat Module (DSM)
- Damaged seat motor connector with shorted pins or moisture intrusion
- Blown seat circuit fuse as a result of the short circuit
3. Symptoms You Will Notice
- Driver seat does not move rearward (recline or slide)
- Seat movement may be intermittent or completely inoperative
4. Step-by-Step Diagnosis
Check for blown fuses in the seat circuit and replace if necessary
Inspect the seat motor wiring harness for chafing, pinching, or damage near the seat frame
Disconnect the seat motor connector and measure for battery voltage on the control circuit wires
Test the seat motor by applying direct battery voltage to see if it operates
If wiring and motor are good, suspect a failed DSM and perform module self-test or replacement
5. Frequently Asked Questions
Is it safe to drive?▼
Yes, it is generally safe to drive, but the affected seat adjustment function will be disabled. Have it repaired soon to restore full seat adjustability.
How much does it cost to fix?▼
Repair costs typically range from $150 to $400, depending on whether the issue is a simple wiring repair, motor replacement, or module replacement.