What Does B1970 Mean?
This code indicates the Body Control Module (BCM) has detected an electrical short to ground in the passenger seat forward/backward adjustment switch circuit. The BCM monitors the voltage in this circuit and has identified that the signal wire is making unintended contact with a ground path, causing abnormally low voltage readings. This fault prevents proper communication between the seat position switch and the BCM, potentially disabling power seat adjustment functionality.
Common Causes
40%
Damaged or pinched wiring harness under the passenger seat rail, often from items stored under seat or seat track movement
30%
Failed passenger seatback forward switch with internal short to ground
20%
Corroded or moisture-damaged connector terminals at seat switch or BCM causing intermittent ground fault
10%
BCM internal fault in seat control circuit driver or monitoring circuitry
Diagnostic Steps
1
Step 1: Perform visual inspection of passenger seat wiring harness for pinched, chafed, or damaged wires where harness routes along seat rails and floor pan. Check for abraded insulation exposing bare wire contacting metal seat frame or brackets.
2
Step 2: Disconnect passenger seatback forward switch connector and inspect terminals for corrosion, bent pins, or moisture intrusion. Using a digital multimeter, measure resistance from switch signal wire (BCM side) to ground with switch disconnected; reading should be greater than 10K ohms (open circuit). If reading shows continuity or low resistance, wiring harness has short to ground.
3
Step 3: If harness tests good, measure resistance across seatback forward switch terminals with switch in both pressed and released positions per wiring diagram specifications. Compare readings to manufacturer specs (typically open circuit when not pressed, closed/low resistance when pressed). A constant low resistance to ground indicates failed switch.
4
Step 4: Repair identified fault (replace damaged wiring section, repair connector, or replace switch). Clear codes, cycle seat switch through full range of motion, and verify code does not return. Test seat adjustment functionality in all directions to confirm proper operation.
5
Step 5: If no external faults found and wiring tests good to BCM connector, suspect BCM internal fault. Verify BCM connector terminals are clean and tight, then consider BCM replacement or professional-level BCM diagnostics.
Estimated Repair Cost
$100 - $600
Parts + labor, varies by vehicle and location
This code indicates the Body Control Module (BCM) has detected an electrical short to ground in the passenger seat forward/backward adjustment switch circuit. The BCM monitors the voltage in this circuit and has identified that the signal wire is making unintended contact with a ground path, causing...
The most common cause of B1970 (Passenger Seatback Forward Switch Circuit Short to Ground) is: Damaged or pinched wiring harness under the passenger seat rail, often from items stored under seat or seat track movement
Typical repair costs for B1970 range from $100 to $600, depending on the vehicle, location, and whether you do it yourself or go to a shop.
Safe to continue driving as this only affects passenger seat adjustment convenience features and does not impact vehicle operation or safety systems. Repair at earliest convenience to restore full seat functionality and prevent potential electrical drain issues.
Start by connecting an OBD2 scanner to read the code and any freeze frame data. Then follow the diagnostic steps specific to B1970 to identify the root cause.
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Quick Info
Category
Body
System
Body Control and Power Seat System
Difficulty
Type
Manufacturer
Recommended Tools
OBD2 Scanner
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