Driver Seat Rear Up Circuit Short to Ground
The B1658 code indicates that the Body Control Module (BCM) or Seat Control Module (SCM) has detected a short to ground in the signal or power circuit for the driver seat rear up switch or motor. This prevents the rear portion of the seat cushion from adjusting vertically.
1. Commonly Affected Makes
2. Most Common Causes
- Internal short in the driver seat adjustment switch (rear up)
- Wiring harness for the rear up circuit chafed or pinched against the chassis (short to ground)
- Rear vertical adjustment motor with internal winding short to ground
- Faulty Seat Control Module (SCM) or BCM (rare)
3. Symptoms You Will Notice
- Driver seat rear height adjustment inoperative
- Seat may move in other directions but not rear up/down
4. Step-by-Step Diagnosis
Check for technical service bulletins (TSBs) related to seat wiring or switches
Inspect the driver seat switch assembly for damage or internal short
Test the rear up motor circuit for continuity to ground using a multimeter
Check wiring harness under the seat for chafing, pinching, or corrosion
If wiring and switch are good, test motor resistance; if shorted, replace motor
If all components test OK, suspect SCM/BCM fault and perform module diagnostics
5. Frequently Asked Questions
Is it safe to drive?▼
Yes, it is generally safe to drive, but the rear seat height adjustment will not work. Have it repaired soon for comfort and to prevent further electrical issues.
How much does it cost to fix?▼
Repair costs typically range from $100 to $400, depending on whether the switch, wiring, or motor needs replacement. Module replacement can be more expensive.