The B1251 code is related to the Tire Pressure Sensor and Body Control Module (BCM) in a vehicle’s Tire Pressure Monitor System (TPMS).
When this code is triggered, it indicates a low battery in the tire pressure sensor, which causes the TPMS warning light to flash continuously.
The symptoms of this issue include the flashing TPMS warning light.
The causes can be attributed to faulty sensors or a malfunctioning BCM.
To fix the problem, it is important to seek professional assistance for an accurate diagnosis and repair.
B1251: Low Battery in the tire Pressure Sensor
What does it mean
The B1251 code indicates a low battery in the tire pressure sensor during training. It does not necessarily mean the sensor is faulty.
Replacing the sensor may not prevent the code from recurring. To prevent it, use a compatible TPMS tool to check and replace the sensor’s battery if needed.
What are the symptoms
What are the symptoms associated with the B1251 code?
- The Tire Pressure Monitor System (TPMS) Warning Light is ON.
- Other symptoms may vary depending on the specific vehicle.
- It is important to address the issue promptly to avoid safety risks.
- Ignoring the warning light may cause more damage or expensive repairs.
The main symptom linked to the B1251 code is the illumination of the Tire Pressure Monitor System (TPMS) Warning Light. This light indicates a problem with the tire pressure sensor. However, there may be other symptoms depending on the specific vehicle.
What are the causes
Causes of the B1251 Code:
- Faulty Tire Pressure Sensor: A malfunctioning sensor can trigger the B1251 code and illuminate the Tire Pressure Monitoring System (TPMS) warning light. Regular maintenance and inspection can help prevent this issue.
- Faulty Body Control Module (BCM): A defective BCM can interfere with the proper functioning of the tire pressure sensor, leading to the B1251 code. Regular system checks and updates can help prevent this issue.
- Open or Shorted BCM Harness: Damaged or faulty wiring in the BCM harness can disrupt communication between the tire pressure sensor and the BCM, resulting in the B1251 code. Regular inspection and maintenance of the wiring harness can help prevent this issue.
- Poor Electrical Connection in the BCM Circuit: A loose or corroded electrical connection within the BCM circuit can cause communication errors and trigger the B1251 code. Ensuring proper connection and maintenance of the BCM circuit can help prevent this issue.
- Other Potential Causes: There may be additional factors not listed here that could also trigger the B1251 code.
What Tools are Needed to diagnose
To diagnose the B1251 code, the technician will need a diagnostic scan tool. This tool is necessary to accurately diagnose the problem and retrieve any stored trouble codes from the vehicle’s computer system.
Along with the diagnostic scan tool, here are some recommended tools for dealing with the B1251 code:
- Multimeter: This tool is used to measure electrical voltages, resistance, and continuity in the circuits related to the tire pressure sensor and body control module.
- Wiring diagram: A wiring diagram is needed to understand the electrical connections and components involved in the tire pressure monitoring system.
- TPMS tool: A TPMS tool is useful for testing and reprogramming the tire pressure sensors, as well as resetting the system after repairs.
- Inspection tools: Visual inspection tools like a flashlight and mirror can help inspect the wiring harnesses, connectors, and sensor components for any signs of damage or corrosion.
How to fix Step by Step
Step 1: Perform a thorough inspection of the tire pressure sensor and body control module to diagnose the B1251 code.
Step 2: Check for any faulty tire pressure sensors or a faulty body control module as potential causes of the B1251 code.
Step 3: Visually inspect the wiring harness and connectors related to the tire pressure sensor, looking for any damaged components or broken, bent, pushed out, or corroded connector pins.
Step 4: Regularly maintain the tire pressure sensor by checking the tire pressure, ensuring the sensors are properly calibrated, and replacing any faulty sensors or those with low battery.
Step 5: Address the B1251 code promptly to avoid potential safety risks and prevent costly repairs.
What are the Common Diagnosis Mistakes
- Overlooking Wiring Harness and Connector Issues: A common diagnostic mistake is not considering potential problems with the wiring harness and connectors when addressing the B1251 code. It’s crucial to inspect these components for damage, such as corrosion, bent pins, or loose connections, as they can often be the root cause of the issue.
- Failing to Use Multimeter for Troubleshooting: Neglecting to use a multimeter to test for continuity and resistance in the wiring harness is another oversight. This tool is essential for accurately diagnosing electrical issues related to the B1251 code.
- Ignoring Visual Inspection of the Harness: Not visually inspecting the wiring harness for visible signs of damage or wear can lead to misdiagnosis. A thorough visual check can sometimes reveal obvious problems that are causing the code.
- Misattributing the Cause to Tire Pressure Sensor or Body Control Module: Assuming that the tire pressure sensor or body control module is solely responsible for the B1251 code without first ruling out wiring and connector issues is a common mistake. While these components may contribute to the fault, it is important to address simpler potential causes first.
What is the Repair Cost
The cost of repairing the B1251 code varies depending on factors such as location, vehicle make, model, and engine type. Labor rates range from $75 to $150 per hour, with additional costs for parts and repairs.
Regular maintenance and inspection of tire pressure sensors and the body control module can help prevent this code.
Consult experts for aftermarket solutions.
Can I drive safely with this code?
Driving with the B1251 code is not recommended as it indicates a low battery in the tire pressure sensor. This can lead to inaccurate readings, compromising vehicle handling, fuel efficiency, and tire safety.
Resetting the TPMS may temporarily turn off the warning light, but professional help is needed to diagnose and repair the underlying issue.
Wrapping Up
The B1251 code indicates a low battery in the tire pressure sensor, leading to the TPMS warning light flashing and remaining on continuously.
It is important to promptly address this issue to avoid further damage or expensive repairs. Possible causes include a faulty tire pressure sensor or a malfunctioning BCM.
Professional assistance is recommended for accurate diagnosis and repair. Ignoring the warning can compromise safety.