What Does B1770 Mean?
This code indicates the Body Control Module (BCM) has detected an open circuit in the driver's seat backward movement control circuit. The BCM monitors the electrical continuity of the power seat positioning system and has identified a break in the wiring, switch, or motor circuit that controls rearward seat travel. This prevents the seat from moving backward electronically, though manual adjustment may still be possible on some vehicles.
Common Causes
40%
Broken or disconnected wiring harness between seat switch and seat motor
30%
Failed driver seat switch assembly with open backward control contact
20%
Faulty seat motor with open backward movement circuit or brushes
10%
Corroded or damaged connector at seat motor or switch
Diagnostic Steps
1
Step 1: Perform visual inspection of driver seat wiring harness underneath and sides of seat, checking for pinched, cut, or disconnected wires especially at moving pivot points where seat track flexes
2
Step 2: Using a digital multimeter, check for continuity on the backward control circuit from the seat switch connector to the seat motor connector with ignition on; expected reading should be less than 5 ohms with switch activated in backward position
3
Step 3: Disconnect seat switch and check for continuity across the backward movement terminals while activating switch; should show continuity (0-2 ohms) when pressed backward, infinite resistance when released
4
Step 4: Test seat motor directly by applying 12V power and ground to backward movement terminals; motor should run smoothly drawing 3-8 amps typically, confirming motor functionality
5
Step 5: Inspect all connectors for corrosion, bent pins, or moisture intrusion; clean with electrical contact cleaner and check for proper pin tension
6
Step 6: Clear codes and retest seat operation in all directions; verify code does not return and seat moves smoothly backward through full range of travel
Estimated Repair Cost
$100 - $600
Parts + labor, varies by vehicle and location
This code indicates the Body Control Module (BCM) has detected an open circuit in the driver's seat backward movement control circuit. The BCM monitors the electrical continuity of the power seat positioning system and has identified a break in the wiring, switch, or motor circuit that controls rear...
The most common cause of B1770 (Seat Driver Backward Circuit Open) is: Broken or disconnected wiring harness between seat switch and seat motor
Typical repair costs for B1770 range from $100 to $600, depending on the vehicle, location, and whether you do it yourself or go to a shop.
This code does not affect vehicle safety or drivability and the vehicle is safe to drive. The only impact is reduced driver comfort and inability to adjust seat position backward electronically; repair can be scheduled at convenience.
Start by connecting an OBD2 scanner to read the code and any freeze frame data. Then follow the diagnostic steps specific to B1770 to identify the root cause.
OBDHut Mobile App
Scan codes directly from your car with the OBDHut app.
Coming Soon
Quick Info
Category
Body
System
Body Comfort and Convenience Systems
Difficulty
Type
Manufacturer
Recommended Tools
OBD2 Scanner
A quality scan tool helps you read codes, view live data, and clear faults.
