The OBD code B1877 for Ford indicates an issue with the Seat Belt Driver Pretensioner circuit.
Symptoms include the Air Bag Warning Light being ON.
This code is commonly caused by a faulty Seat Belt Driver Pretensioner or poor electrical connections.
It is a serious issue that affects the vehicle’s safety systems.
To fix it, inspect the wiring harness, connectors, and components for any damage or corrosion.
Repair Importance Level | 10.0 (Out of 10) |
Estimated Repair Time | Approximately 1.0 hour |
Repair Difficulty Level | 10.0 (Out of 10) |
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Symptoms of the Ford b1877 OBD Code
The Ford B1877 fault code indicates a potential issue with the airbag passenger occupant classification system.
- Symptoms: Air Bag Warning Light ON
Causes of the Ford b1877 OBD Code
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Possible triggers for Ford B1877 include faulty airbag module, wiring issues, or a defective clock spring.
- B1877 can be caused by a faulty Seat Belt Driver Pretensioner.
- A Seat Belt Driver Pretensioner harness that is open or shorted.
- A Seat Belt Driver Pretensioner circuit with a poor electrical connection.
- A faulty Restraints Control Module (RCM).
Fixing Ford Error Code b1877 Step By Step
To resolve Ford fault code B1877, inspect and repair the driver side airbag circuit.
- To fix Ford OBDII code B1877, first, review the ‘Possible Causes’ mentioned above and visually examine the corresponding wiring harness and connectors.
- Ensure to check for any damaged components and inspect the connector pins for signs of being broken, bent, pushed out, or corroded.
- Next, check the wiring leading to the seat belt pretensioner for any issues such as breaks or shorts.
- Test the seat belt pretensioner for proper operation and resistance.
- Replace the seat belt pretensioner if necessary.
- Clear the fault codes using a compatible scan tool and perform a test drive to verify the repair.
Cost Of Fixing Ford b1877 Fault Code
Diagnosing and repairing fault code B1877 in a Ford vehicle typically involves inspecting and addressing seat belt pretensioner circuit issues.
The cost to diagnose and fix Ford OBD code B1877 is typically based on 1. 0 hour of labor, with rates ranging from $75 to $150 per hour.
The total cost will depend on shop rates, complexity of the repair, and any additional parts needed.
Details of the Ford b1877 OBD Code
Ford fault code B1877 relates to the airbag passenger occupant classification system.
Ford OBD code B1877 means a driver power window up switch circuit failure.
This code is triggered by the smart junction box (SJB) when it detects a malfunction in the power window up switch circuit.
The SJB monitors the signals from the power window switches to control the power windows in the vehicle.
When it detects a fault in the circuit related to the driver power window up switch, it sets code B1877.
Mechanic’s Tech Notes
For Ford code B1877, check for a fault in the driver side airbag circuit.
To diagnose and fix OBDII code B1877 in a Ford vehicle, start by visually inspecting the wiring harness and connectors related to the Transmission Control Module (TCM).
Look for any damage or corrosion on the connector pins.
Use a multimeter to check the power and ground connections to the TCM.
Additionally, use a scan tool to confirm if the TCM is communicating over the Controller Area Network (CAN) network.
If necessary, consider reprogramming or reflashing the TCM.
This process can help identify and address issues causing the B1877 fault code.
FAQ
OBD code B1877 in a Ford means an issue with the Seat Belt Driver Pretensioner circuit. Check wiring, connectors, and components for faults to resolve the problem.
To diagnose OBD code B1877 in a Ford with Air Bag Warning Light ON, check the Seat Belt Driver Pretensioner, harness, connectors, and Restraints Control Module for faults.
Common symptoms of OBD code B1877 in a Ford vehicle include the Air Bag Warning Light being ON. Possible causes are a faulty Seat Belt Driver Pretensioner or related wiring issues.

Wrap Up
If your Ford is showing OBD code b1877 and your airbag warning light is illuminated, it may indicate a fault in the driver side airbag circuit.
This could be caused by a malfunctioning airbag module, faulty wiring connections, or a damaged clock spring.
To address Ford OBD code b1877, start by inspecting the wiring harness and connectors related to the driver side airbag system.
Check for any loose connections, frayed wires, or damaged components.
Test the airbag module and clock spring for proper functionality and replace any faulty parts as needed.