C129D Code - Brake Pedal Position Sensor 4 Circuit Low Input
Quick Answer
The C129D code indicates a problem with the Brake Pedal Position Sensor 4 Circuit, specifically a low input signal. Common causes include Faulty brake pedal position sensor, Damaged wiring or connectors in the sensor circuit, Issues with the ECM. Severity is High - diagnose this code as soon as possible. Driving is not recommended if the warning light is flashing, the engine runs poorly, or safety-related symptoms are present.
- What it means
- C129D indicates Brake Pedal Position Sensor 4 Circuit Low Input.
- Common causes
- Common causes include Faulty brake pedal position sensor, Damaged wiring or connectors in the sensor circuit, Issues with the ECM.
- Severity
- High - diagnose this code as soon as possible.
- Can I drive?
- Driving is not recommended if the warning light is flashing, the engine runs poorly, or safety-related symptoms are present.
Fix Your Car Smarter
Try the New AutoCodes App!
Get complete OBDII diagnostics, repair solutions, and cost estimates, plus AI chat support on demand.
Code C129D Description
The C129D code indicates a problem with the Brake Pedal Position Sensor 4 Circuit, specifically a low input signal. The brake pedal position sensor is a vital component of the vehicle's braking system as it monitors the position of the brake pedal and sends this information to the vehicle's engine control module (ECM). This sensor helps the ECM determine when to activate the brake lights, disengage cruise control, and other functions related to braking.
Common Causes of C129D
- Faulty brake pedal position sensor
- Damaged wiring or connectors in the sensor circuit
- Issues with the ECM
- Corrosion or contamination in the sensor circuit
- Electrical issues such as short circuits or open circuits
Symptoms of C129D
- Illumination of the brake warning light on the dashboard
- Issues with cruise control disengagement
- Inaccurate brake light activation
- Stability control system malfunctions
How to Fix C129D
- Begin by conducting a thorough inspection of the brake pedal position sensor and its circuit.
- Test the sensor's functionality using a multimeter to check for proper voltage and resistance.
- Check the wiring and connectors for any signs of damage or corrosion and repair or replace as needed.
- Clear the diagnostic trouble codes from the ECM and test drive the vehicle to ensure the issue has been resolved.
- If the problem persists, further diagnosis may be needed to determine the exact cause of the low input signal.
Cost to Fix C129D
The typical repair costs for addressing the C129D code can vary depending on the specific cause of the issue. In general, replacing a faulty brake pedal position sensor can cost anywhere from $100 to $200, while addressing wiring or connector issues may add to the overall repair costs. Labor rates at auto repair shops can range from $80 to $150 per hour, so it's advisable to check local rates for a more accurate estimate.
Need more information about the C129D code?
Need more information on how to fix the C129D code? Get Access to Factory Service Manuals
Need Help with the Code?
Get the C129D code diagnosed by a professional: Find a repair shop in your area
Code C129D Information for Specific Makes
- C129D Buick — Brake Pedal Position Sensor 4 Circuit Low Input
- C129D Cadillac — Brake Pedal Position Sensor 4 Circuit Low Input
- C129D Chevrolet — Brake Pedal Position Sensor 4 Circuit Low Input
- C129D GMC — Brake Pedal Position Sensor 4 Circuit Low Input
Frequently Asked Questions about C129D Code
1. What are the common symptoms of OBDII code C129D (Brake Pedal Position Sensor 4 Circuit Low Input)?
The common symptoms of this code may include issues with the brake lights, cruise control not functioning properly, and potential stability control system malfunctions.
2. What are the possible causes of OBDII code C129D?
Possible causes of this code include a faulty brake pedal position sensor, damaged wiring or connectors in the brake pedal position sensor circuit, or a problem with the brake control module.
3. How can I diagnose OBDII code C129D?
Diagnosing this code usually involves using a scan tool to retrieve the code and then performing a thorough inspection of the brake pedal position sensor and its related wiring and connectors.
4. Can I still drive my vehicle with OBDII code C129D?
It is not recommended to drive your vehicle with this code present, as it can affect the proper functioning of crucial safety systems like stability control and brake lights.
5. How do I repair OBDII code C129D?
To repair this code, you may need to replace the brake pedal position sensor, repair any damaged wiring or connectors, or reprogram the brake control module, depending on the exact cause of the issue.
6. Will disconnecting the battery reset OBDII code C129D?
Disconnecting the battery may reset the code temporarily, but it is essential to address the underlying issue causing the code to prevent it from reoccurring.
7. How much does it cost to fix OBDII code C129D?
The cost of fixing this code can vary depending on the cause of the issue, the extent of the repair needed, and the labor rates of the repair shop. It is recommended to get a diagnostic and repair estimate from a qualified mechanic.
8. Can a DIY enthusiast fix OBDII code C129D at home?
Depending on your level of mechanical expertise and access to the necessary tools, you may be able to diagnose and repair this code at home. However, it is crucial to ensure you have the proper knowledge and resources before attempting the repair.
9. Are there any recalls related to OBDII code C129D?
Recalls related to this specific OBDII code may vary depending on the make and model of your vehicle. It is recommended to check with the manufacturer or a dealership to see if there are any relevant recalls for your vehicle.
10. How often does OBDII code C129D occur in vehicles?
The occurrence of this specific OBDII code can vary among different vehicle models and manufacturers. If you encounter this code, it is essential to address it promptly to avoid potential safety issues.
Discuss the causes and fixes for C129D OBDII Code
Code C129D comments
No comments found for this page.
Fix Your Car Smarter
Try the New AutoCodes App!
Get complete OBDII diagnostics, repair solutions, and cost estimates, plus AI chat support on demand.