What Does B1971 Mean?
This diagnostic trouble code indicates that the Body Control Module (BCM) or Seat Control Module has detected an abnormal short to ground condition in the electrical circuit controlling the passenger seat rearward adjustment switch. The control module detected voltage levels below the expected threshold, indicating the circuit is shorted directly to chassis ground rather than operating within normal parameters. This affects the power seat adjustment system and prevents proper electronic control of the passenger seat positioning.
Common Causes
45%
Damaged or chafed wiring harness beneath the passenger seat causing direct ground contact, often from seat track movement or items trapped under the seat
30%
Faulty passenger seat rearward adjustment switch with internal short to ground
15%
Corroded or moisture-damaged connector at the seat switch or seat control module causing short circuit
10%
Failed seat control module with internal circuit fault on the rearward switch input channel
Diagnostic Steps
1
Step 1: Perform visual inspection of the passenger seat adjustment switch and all accessible wiring harnesses beneath and behind the seat, looking for chafed insulation, pinched wires, or signs of moisture intrusion. Check for items trapped under seat tracks that may have damaged wiring.
2
Step 2: Disconnect the passenger seat rearward adjustment switch connector and measure resistance between the switch signal circuit terminal and chassis ground using a digital multimeter. Reading should be infinite (open circuit); any continuity indicates a short to ground in the wiring harness or switch.
3
Step 3: If no short is detected at the switch, disconnect the seat control module connector and measure resistance from the rearward switch signal wire at the module harness side to chassis ground. Infinite resistance indicates the module has an internal fault; continuity indicates wiring harness damage between the switch and module.
4
Step 4: If wiring harness is confirmed good, test the seat adjustment switch itself by measuring resistance across the rearward switch terminals in both pressed and unpressed states per manufacturer specifications. Replace switch if resistance values are incorrect or show short to ground.
5
Step 5: After replacing faulty component (wiring, switch, or module), clear diagnostic codes, operate the seat rearward adjustment function through full range of motion, and verify code does not return and seat operates normally in all directions.
Estimated Repair Cost
$120 - $650
Parts + labor, varies by vehicle and location
This diagnostic trouble code indicates that the Body Control Module (BCM) or Seat Control Module has detected an abnormal short to ground condition in the electrical circuit controlling the passenger seat rearward adjustment switch. The control module detected voltage levels below the expected thres...
The most common cause of B1971 (Passenger Seatback Rearward Switch Circuit Short to Ground) is: Damaged or chafed wiring harness beneath the passenger seat causing direct ground contact, often from seat track movement or items trapped under the seat
Typical repair costs for B1971 range from $120 to $650, depending on the vehicle, location, and whether you do it yourself or go to a shop.
This code does not affect vehicle drivability or safety systems and the vehicle is safe to drive. The passenger seat rearward adjustment function will be inoperative, which may affect passenger comfort and proper seating position but does not create an immediate safety hazard.
Start by connecting an OBD2 scanner to read the code and any freeze frame data. Then follow the diagnostic steps specific to B1971 to identify the root cause.
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Quick Info
Category
Body
System
Power Seat Adjustment System
Difficulty
Type
Manufacturer
Recommended Tools
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