What Does B1972 Mean?
This code indicates the Body Control Module (BCM) has detected that the passenger rear seat up switch circuit is shorted directly to battery voltage instead of operating within its normal voltage range. The BCM monitors the seat control switch inputs and has identified continuous high voltage on this circuit when it should be reading ground, open, or a reference voltage. This affects the power seat control system, specifically the rear passenger seat folding/positioning mechanism.
Common Causes
45%
Damaged wiring harness with insulation worn through causing direct contact with battery voltage source, commonly at pinch points near seat tracks or hinges
30%
Faulty seat up switch with internal short circuit allowing constant battery voltage feed-through
15%
Corroded or damaged connector pins at the seat switch or BCM creating unintended voltage path
10%
BCM internal circuit fault misreading switch input voltage
Diagnostic Steps
1
Step 1: Perform visual inspection of passenger rear seat wiring harness, focusing on areas where wiring routes near seat tracks, hinges, and metal brackets. Look for chafed, pinched, or melted insulation exposing copper conductors.
2
Step 2: Disconnect the passenger rear seat up switch connector and use a digital multimeter to measure voltage at the BCM-side harness connector terminal for the switch signal wire. With ignition on, reading should be 0-5V reference voltage, not battery voltage (12-14V).
3
Step 3: If battery voltage is present at disconnected harness, trace the wire back toward the BCM checking for short to power at intermediate connectors and along the harness route. Use wiring diagram to identify wire color and circuit path.
4
Step 4: If harness tests normal, test the seat up switch itself by measuring resistance across switch terminals in both open and closed positions. Replace switch if internal short is detected showing continuity to battery voltage terminal when it should be open.
5
Step 5: Clear the DTC code and cycle the seat up switch through its normal operation range while monitoring live data for proper voltage transitions. Verify code does not return and switch operates correctly.
Estimated Repair Cost
$150 - $650
Parts + labor, varies by vehicle and location
This code indicates the Body Control Module (BCM) has detected that the passenger rear seat up switch circuit is shorted directly to battery voltage instead of operating within its normal voltage range. The BCM monitors the seat control switch inputs and has identified continuous high voltage on thi...
The most common cause of B1972 (Passenger Rear Seat Up Switch Circuit Short to Battery) is: Damaged wiring harness with insulation worn through causing direct contact with battery voltage source, commonly at pinch points near seat tracks or hinges
Typical repair costs for B1972 range from $150 to $650, depending on the vehicle, location, and whether you do it yourself or go to a shop.
Vehicle is safe to drive as this affects only the power seat adjustment feature and does not impact vehicle operation or safety systems. Repair at convenience to restore seat folding/positioning functionality and prevent potential battery drain from continuous short circuit.
Start by connecting an OBD2 scanner to read the code and any freeze frame data. Then follow the diagnostic steps specific to B1972 to identify the root cause.
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Quick Info
Category
Body
System
Body Control and Comfort Systems - Power Seat Control
Difficulty
Type
Manufacturer
Recommended Tools
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