B1878
Low Severity (Level 1)Seatbelt Driver Pretensioner Circuit Short to Battery
B1878 usually means seatbelt Driver Pretensioner Circuit Short to Battery.
Can you still drive with B1878?
✅Safe to drive — this is an informational or minor issue. Schedule diagnosis at your convenience.
Typical repair cost: $120 – $1000
Severity Level 1 — Low
This code indicates a minor issue that is unlikely to cause immediate driveability problems. You can typically continue driving but should have the vehicle inspected at your earliest convenience.
Common Symptoms
- Seat memory settings not saving or recalling correctly
- Power seat won't move in one or more directions
- Power seats staying on or functioning when they shouldn't (powered continuously)
- Excessive current draw on the power seat system circuit (fuse may blow repeatedly)
Possible Causes
- Damaged wiring in the power seat system harness shorted to a 12V power source — wiring insulation chafed through from rubbing against metal body panels
- Water intrusion or corrosion in power seat system electrical connector causing internal short to battery voltage
- Failed seat motor/module — internal short to power within the component
- Aftermarket accessory installation tapped into the wrong circuit, back-feeding 12V
Common Fixes
- Scan vehicle with a professional-grade OBD2 scanner to read all stored codes and freeze frame data — note the conditions when the code set ($2-144 at shop, free at auto parts store for basic scan)
- Visually inspect the power seat system wiring harness and connectors — look for chafed wires, melted insulation, green corrosion, loose pins, or rodent damage (often free to check yourself, $113 diagnostic fee at shop)
- Repair or replace damaged section of wiring harness where short is located — solder and heat-shrink all connections, don't use crimp connectors on critical circuits ($197-243 depending on accessibility)
- If seat motor/module is internally shorted, replace with a quality OEM or OEM-equivalent aftermarket unit ($100-800)
- Clean all ground points related to the power seat system — remove bolt, sand contact surface to bare metal, apply dielectric grease, and torque to spec ($30-198 at shop)
Estimated Repair Cost
These are estimated costs based on generic repair data. Actual costs may vary depending on your vehicle, location, and labor rates.
Frequently Asked Questions
What does B1878 mean?
B1878 stands for "Seatbelt Driver Pretensioner Circuit Short to Battery". B1878 usually means seatbelt Driver Pretensioner Circuit Short to Battery.
Can you drive with B1878?
Safe to drive — this is an informational or minor issue. Schedule diagnosis at your convenience.
How much does it cost to fix B1878?
Repair costs for B1878 typically range from $120 to $1000, depending on your vehicle make, model, and local labor rates. Common fixes include: Scan vehicle with a professional-grade OBD2 scanner to read all stored codes and freeze frame data — note the conditions when the code set ($2-144 at shop, free at auto parts store for basic scan); Visually inspect the power seat system wiring harness and connectors — look for chafed wires, melted insulation, green corrosion, loose pins, or rodent damage (often free to check yourself, $113 diagnostic fee at shop); Repair or replace damaged section of wiring harness where short is located — solder and heat-shrink all connections, don't use crimp connectors on critical circuits ($197-243 depending on accessibility).
Will B1878 clear itself?
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