U129C Code - F-CAN Malfunction EPS Control Unit and Driving Support System Control Unit
Quick Answer
The Diagnostic Trouble Code (DTC) sets when a communication malfunction was detected between the Electric Power Steering (EPS) Control Unit and the Driving Support System Control Unit. Common causes include Faulty Electric Power Steering (EPS) Control Unit, Electric Power Steering (EPS) Control Unit harness is open or shorted, Electric Power Steering (EPS) Control Unit circuit poor electrical connection. 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
- U129C indicates F-CAN Malfunction EPS Control Unit and Driving Support System Control Unit.
- Common causes
- Common causes include Faulty Electric Power Steering (EPS) Control Unit, Electric Power Steering (EPS) Control Unit harness is open or shorted, Electric Power Steering (EPS) Control Unit circuit poor electrical connection.
- 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.
Code U129C Description
What are the Possible Causes of the DTC U129C?
- Faulty Electric Power Steering (EPS) Control Unit
- Electric Power Steering (EPS) Control Unit harness is open or shorted
- Electric Power Steering (EPS) Control Unit circuit poor electrical connection
- Faulty Driving Support System Control Unit
How to Fix the DTC U129C?
Review the 'Possible Causes' above and visually examine the corresponding wiring harness and connectors. Check for damaged components and inspect connector pins for signs of being broken, bent, pushed out, or corroded.
What is the Cost to Diagnose the Code?
Labor: 1.0
To diagnose the U129C code, it typically requires 1.0 hour of labor. Rates vary by location, vehicle, and shop. Many shops charge between $80–$150 per hour; dealerships and metro areas may be higher, independents may be lower.
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Information for Specific Makes
- U129C Acura — F-CAN Malfunction EPS Control Unit and Driving Support System Control Unit
- U129C Honda — F-CAN Malfunction EPS Control Unit and Driving Support System Control Unit
Frequently Asked Questions about U129C Code
1. What does the OBDII code U129C indicate?
The U129C code indicates a communication malfunction between the EPS (Electric Power Steering) Control Unit and the Driving Support System Control Unit via the F-CAN network.
2. What are the common symptoms of the U129C code?
Symptoms may include a loss of power steering assistance, illuminated warning lights on the dashboard, or issues with driving support features like lane-keeping assist or adaptive cruise control.
3. What causes the U129C code to appear?
Common causes include faulty wiring or connectors in the F-CAN network, a malfunctioning EPS Control Unit, a failing Driving Support System Control Unit, or software-related issues.
4. Can I drive my car with the U129C code?
Driving with this code may be unsafe, especially if power steering or driving support systems are compromised. It’s best to address the issue promptly.
5. How do you diagnose the U129C code?
Diagnosis typically involves scanning the vehicle for codes, inspecting the F-CAN wiring and connectors, testing the EPS Control Unit and Driving Support System Control Unit, and checking for software updates.
6. Is the U129C code related to a specific vehicle brand?
While the U129C code can appear on various vehicles, it is more commonly associated with certain Honda and Acura models.
7. How do you fix the U129C code?
Repairs may include fixing or replacing damaged F-CAN wiring, repairing connectors, replacing a malfunctioning EPS Control Unit or Driving Support System Control Unit, or updating software.
8. Can a weak battery cause the U129C code?
Yes, a weak or failing battery can cause communication issues on the F-CAN network, potentially triggering the U129C code.
9. What tools are needed to fix the U129C code?
You’ll need an OBDII scanner, a multimeter for testing electrical connections, and possibly manufacturer-specific diagnostic tools for advanced troubleshooting.
10. How much does it cost to fix the U129C code?
The repair cost depends on the root cause. Simple wiring repairs may cost under $100, while replacing a control unit can cost several hundred dollars or more, plus labor charges.
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