OBD code B1257 indicates a fault with the Air Temperature External Sensor circuit.
Symptoms include the Engine Light being ON.
This code is commonly caused by a faulty sensor, open/shorted sensor harness, or poor electrical connection.
It’s not a severe issue but can affect engine performance.
To fix, inspect the sensor, wiring harness, and connectors for any damage or poor connections.
| Repair Importance Level | 10.0 (Out of 10) |
| Estimated Repair Time | Approximately 1.0 hour |
| Repair Difficulty Level | 10.0 (Out of 10) |
Symptoms of the b1257 OBD Code
The vehicle displays a warning light indicating an issue with the speed control switch.
- Symptoms: Service Engine Soon Warning Light is ON.
- Loss of communication with the multifunction control module.
- Erratic behavior of vehicle systems.
- Engine may stall unexpectedly.
- Difficulty starting the engine.
Causes of the b1257 OBD Code
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B1257 code is typically triggered by a malfunction in the vehicle’s speed control servo power circuit.
- B1257 can be caused by a Faulty Air Temperature External Sensor.
- An open or shorted Air Temperature External Sensor harness.
- A poor electrical connection in the Air Temperature External Sensor circuit.
Fixing Error Code b1257 Step By Step
To address fault code B1257, inspect and replace the vehicle’s speed control switch.
- To fix OBDII code B1257, first, review the possible causes related to this code.
- Visually inspect the wiring harness and connectors associated with the brake fluid level sensor circuit.
- Check for any damaged components and ensure the connector pins are not broken, bent, pushed out, or corroded.
- If no visible issues are found, test the brake fluid level sensor for proper operation.
- Replace the sensor if it fails the test.
- Clear the fault codes and perform a road test to verify the repair.
Cost Of Fixing b1257 Fault Code
The repair for fault code B1257 may involve replacing the vehicle’s speed control switch.
The cost to diagnose and fix OBD code B1257 depends on the estimated 1. 0hour repair time.
Labor rates usually range from $75 to $150 per hour, so the general cost could be between $75 and $150. Factors like shop rates and the complexity of the repair can influence the final cost.
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Details of the b1257 OBD Code
B1257 code indicates a speed sensor input issue in the vehicle’s system.
OBD code B1257 means a fault has been detected in the speed control switch.
This code is triggered by the Body Control Module (BCM) when it detects an issue with the speed control switch circuit.
The speed control switch is typically located on the steering wheel or steering column and is used to set and adjust the vehicle’s speed control system.
When this switch malfunctions or there is a circuit issue, the BCM will set code B1257 to indicate a problem with the speed control switch.
Mechanic’s Tech Notes
For fault code B1257, refer to detailed diagnostic information for troubleshooting guidance and repair instructions.
To diagnose and fix OBDII code B1257, start by checking the Transmission Control Module (TCM) power and ground using a multimeter.
Verify TCM communication over the Controller Area Network (CAN) using a scan tool.
If the TCM does not respond, reprogramming or reflashing may be necessary.
Visually inspect the wiring harness and connectors for any damage, and check connector pins for signs of corrosion, bending, or breakage.
This thorough inspection can help identify and resolve issues related to code B1257.
FAQ
OBD code B1257 indicates a fault with the Air Temperature External Sensor. Check sensor, wiring, and connectors for issues causing the Engine Light to illuminate.
Common symptoms for OBD code B1257 include Engine Light ON. Causes may be a faulty Air Temperature External Sensor or related wiring issues. Fix: Inspect and repair sensor and wiring.
Diagnose OBD code B1257 by checking the Air Temperature External Sensor and its wiring for faults. Repair any issues found to resolve the problem.
Wrap Up
If your vehicle displays OBD code b1257, you may experience issues with the speedometer, ABS system, or erratic shifting.
This code typically indicates a problem with the vehicle speed sensor circuit, such as a faulty speed sensor, damaged wiring, or poor connections.
To address OBD code b1257, start by inspecting the vehicle speed sensor and its wiring harness for any signs of damage or corrosion.
Test the sensor’s resistance and check for proper voltage supply.
Ensure all connectors are securely attached and free of debris.
Replace the speed sensor if necessary to resolve the issue.
