B1972: Rear Passenger Seat Up Switch Short to Battery
The B1972 code indicates that the Seat Control Module (SCM) or Body Control Module (BCM) has detected an abnormally high voltage on the rear passenger seat 'UP' (raise) position switch circuit. This switch is part of the power seat adjustment system and normally operates by interrupting or changing a reference signal when the switch is pressed. A 'short to battery' means the signal wire or switch circuit is receiving direct battery voltage instead of the expected reference signal, which the module interprets as a circuit fault. This code is specific to manufacturers that use this nomenclature in their comfort and convenience systems.
1. Commonly Affected Makes
2. Most Common Causes
- Wiring in the right rear seat UP switch circuit shorted to a battery power wire
- Internally damaged right rear seat switch causing voltage leakage
- Switch or seat module connector with bent pins, corrosion, or moisture causing a short
- Seat Control Module (SCM) with internal signal detection failure
- Damaged wiring harness chafing against chassis, exposing conductors to battery voltage
3. Symptoms You Will Notice
- Rear passenger seat power adjustment may not work or works intermittently
- Seat may move unexpectedly or fail to respond to switch commands
4. Step-by-Step Diagnosis
Scan for related codes and verify B1972 is present
Visually inspect the right rear seat UP switch wiring and connector for damage, corrosion, or shorts
Test the switch circuit for voltage with a multimeter; compare to manufacturer specifications
Check for continuity between the signal wire and battery voltage; isolate the short
If wiring and switch are okay, test the SCM/BCM for proper operation
5. Frequently Asked Questions
Is it safe to drive?▼
Yes, the severity is low. The seat may not adjust properly, but it does not affect vehicle drivability or safety.
How much does it cost to fix?▼
Typically $100 to $300, depending on whether the switch, wiring repair, or module replacement is needed.