What Does B1758 Mean?
This code indicates that the Body Control Module (BCM) has detected an open circuit in the driver's seat rear vertical adjustment motor circuit, specifically the downward movement circuit. The BCM monitors the electrical continuity and operation of the power seat motor circuits and has identified a break in the wiring, connector, or motor windings that prevents the rear of the driver's seat from moving downward. This is a manufacturer-specific body code related to the power seat control system.
Common Causes
35%
Broken or disconnected wiring harness between BCM and seat motor, often due to seat movement causing wire fatigue
30%
Corroded or loose connector at the seat motor or BCM connection point
25%
Failed seat rear vertical adjustment motor with open windings
10%
Damaged seat control switch with internal open circuit preventing signal completion
Diagnostic Steps
1
Step 1: Perform a visual inspection of the driver's seat wiring harness, checking for pinched, cut, or chafed wires along the seat track and under the seat, paying special attention to wire routing where movement occurs
2
Step 2: Locate and inspect all connectors in the seat motor circuit. Disconnect the seat motor connector and inspect for corrosion, bent pins, or moisture. Check for proper terminal tension and reseat connections
3
Step 3: Using a digital multimeter, test for continuity between the BCM connector and the seat motor connector on the rear down circuit wire (consult wiring diagram for specific pin locations). Should read less than 5 ohms if circuit is intact
4
Step 4: With the motor connector disconnected, measure resistance across the motor terminals corresponding to the rear down function. Should typically read 2-10 ohms. Infinite resistance indicates open motor windings
5
Step 5: Check ground circuit integrity by measuring resistance between the motor ground and chassis ground. Should read less than 1 ohm
6
Step 6: If all wiring and grounds test good, activate the seat control switch while monitoring voltage at the motor connector with a multimeter. Should see battery voltage when switch is pressed. If no voltage, suspect BCM or switch fault
Estimated Repair Cost
$150 - $650
Parts + labor, varies by vehicle and location
This code indicates that the Body Control Module (BCM) has detected an open circuit in the driver's seat rear vertical adjustment motor circuit, specifically the downward movement circuit. The BCM monitors the electrical continuity and operation of the power seat motor circuits and has identified a ...
The most common cause of B1758 (Seat Driver Rear Down Circuit Open) is: Broken or disconnected wiring harness between BCM and seat motor, often due to seat movement causing wire fatigue
Typical repair costs for B1758 range from $150 to $650, depending on the vehicle, location, and whether you do it yourself or go to a shop.
This code does not affect vehicle safety or driveability and the vehicle is safe to operate normally. The only impact is reduced functionality of the driver's seat adjustment, which may affect driver comfort but poses no immediate safety risk.
Start by connecting an OBD2 scanner to read the code and any freeze frame data. Then follow the diagnostic steps specific to B1758 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 Control System - Power Seat Adjustment
Difficulty
Type
Manufacturer
Recommended Tools
OBD2 Scanner
A quality scan tool helps you read codes, view live data, and clear faults.
