OBD-II Generic Error Code P0629: How to Fix It

Q: Can I drive with error code P0629?

It is not recommended. The high voltage condition can cause the fuel pump to run uncontrollably, leading to potential fire hazard or engine stalling. Have it diagnosed and repaired immediately.

Q: Will a bad fuel pump relay cause P0629?

Yes, a stuck or shorted fuel pump relay can send constant power to the fuel pump, causing the high voltage signal detected by the PCM.

Q: Can P0629 be caused by a bad PCM?

Yes, but less commonly. If all wiring and components test good, the PCM may have an internal short. Professional diagnosis is recommended before replacing the PCM.

Q: Does P0629 affect both fuel pumps in a dual-pump system?

No, 'Fuel Pump A' refers to the primary fuel pump. However, if there are multiple fuel pumps, check the specific circuit for the affected pump.

Q: How much does it cost to fix P0629?

If it's a relay or fuse, under $50. Wiring repairs $100-$200. Fuel pump replacement $300-$800. PCM replacement $500-$1000+.

Abstract

Error code P0629 means the Powertrain Control Module (PCM) has detected an abnormally high voltage in the fuel pump A control circuit. This can cause the fuel pump to run continuously or not work at all, leading to drivability issues. Common causes include a faulty fuel pump relay, wiring issues, or a failing PCM.