P0629 OBD-II Trouble Code: Fuel Pump "A" Control Circuit High

Our certified mechanics come to you · 12-month, 12,000-mile warranty

SCHEDULE P0629 DIAGNOSTIC Get a fair and transparent estimate upfront
Red-stars EXCELLENT RATING ON

Cost of diagnosing the P0629 code

P0629 is a diagnostic trouble code (DTC) for "Fuel Pump "A" Control Circuit High". This can happen for multiple reasons and a mechanic needs to diagnose the specific cause for this code to be triggered in your situation. Our certified mobile mechanics can come to your home or office to perform the Check Engine Light diagnostic for $70.00. Once we are able to diagnose the problem, you will be provided with an upfront quote for the recommended fix and receive $30.00 off as a credit towards the repair. All our repairs are backed by our 12-month / 12,000-mile warranty.

Cars Estimate Credit towards follow-up repair Earliest Availability
Ford$70.00$30.00
Toyota$70.00$30.00
BMW$70.00$30.00
SCHEDULE P0629 DIAGNOSTIC Get a fair and transparent estimate upfront

check engine light

P0629 code definition

When the vehicle’s PCM stores the P0629 code, it means that there is an issue with the “A” control circuit in the fuel pump.

What the P0629 code means

Either the vehicle’s PCM, or another supporting control module, has found a problem with the fuel pump’s “A” control circuit. The supporting control modules include, but are not limited to:

  • Body control module
  • Fuel injection control module
  • Alternative fuel control module
  • Turbo control module
  • Anti-lock brake control module
  • Anti-theft module
  • Traction control module
  • Cruise control module
  • Instrument panel control module
  • Climate control module
  • Proximity alert module

What causes the P0629 code?

If the fuel pump “A” control circuit is faulty, the P0629 code is stored. This often means that the malfunction is in a certain area of the system, as opposed to any one component or circuit. Usually, the P0629 code is caused by a defective fuel pump, or a problem with the fuel pump relay. Other causes include:

  • Bad connectors, or shorted or open wiring in the CAN bus harness
  • A loose ground strap in the control module
  • A broken ground wire in the control module
  • A defective CAN bus

What are the symptoms of the P0629 code?

Symptoms of the P0629 code can include: * The code being stored

If the Check Engine Light does not come on right away, the code may be pending.

How does a mechanic diagnose the P0629 code?

The mechanic will focus on the CAN (controller area network) bus. This is what allows the various microcontrollers in the vehicle to communicate independent of a host computer. These microcontrollers regulate practically all of the vehicle’s electrical functions, and the PCM is the master controller.

It is possible for individual controllers to fail, but not common. So first, the mechanic will test each individual module, and replace as needed. The process starts with using an OBD-II scanner, and continues with several (but not necessarily all) of the following:

  • Visually checking connectors and wiring
  • Replacing any damaged wires, connectors and components
  • Re-testing the system
  • If all appears to be working properly, recording the codes and freeze frame data, and then clearing out the codes
  • Running the vehicle to see if the codes come back (if they don’t come back immediately, the problem could be intermittent and more difficult to diagnose)
  • Using a special scanner like Tech II or Autohex to identify the general area in which the problem is occurring
  • Disconnecting and testing all the CAN bus pins (this could be costly)
  • Testing control module ground circuits with battery ground
  • Identifying ground discrepancies using an auxiliary ground cable
  • Checking for corroded or loose connectors that could be increasing circuit resistance
  • Using a digital volt ohmmeter to test individual controller connector continuity, using a CAN bus wiring diagram and pin out value chart
  • Comparing findings with the manufacturer’s specs, and repairing shorted or open circuits as needed

Common mistakes when diagnosing the P0629 code

Repairs are sometimes unsuccessful if the communication failure is misdiagnosed. This is because the wrong component has been identified, and unnecessarily replaced.

How serious is the P0629 code?

This is not a life-threatening issue, but if not corrected, it could lead to more serious problems down the road. You do not have to get the problem fixed immediately, but should have it dealt with in order to avoid more expensive repairs later on.

What repairs can fix the P069 Code?

A mechanic can fix or replace damaged wiring and corroded connectors, and replace any defective modules.

Additional comments for consideration regarding the P0629 code

This type of problem often takes a long time to diagnose, and the wiring harnesses that need to be evaluated and/or repaired are very complex. Often, it is more cost-effective to simply replace any wiring that is suspect.

Need help with a P0629 code?

At YourMechanic, it will be our pleasure to send a mobile mechanic to your home or place of work. We will be glad to provide you with a free quote as well. To arrange an appointment, call us 1-800-701-6230, or use our convenient online form.

trouble codes
P0629
Check Engine Light

Fast and easy Check Engine Light is on Inspection service at your home or office.

SCHEDULE P0629 DIAGNOSTIC
Get a fair and transparent estimate upfront

Recent Check Engine Light is on Inspection reviews

Excellent Rating


YourMechanic Check Engine Light is on Inspection Service

Average Rating

4.5/5

Number of Reviews

3,484

Rating Summary
3,176
153
40
23
92
3,176
153
40
23
92

Richard

10 years of experience
415 reviews
Richard
10 years of experience
This is the second time I’ve had Richard work on my car. He always does an outstanding job and is quick, knowledgeable and professional. Highly recommended!!
2012 DODGE CHALLENGER - CHECK ENGINE LIGHT IS ON - LAS VEGAS, NEVADA

Michael

13 years of experience
372 reviews
Michael
13 years of experience
Mike was an absolute professional when he arrived. He walked me thru the whole process of my repairs and also made good recommendations for preventive issues. His mechanical knowledge and good customer services was a breath of air and greatly appreciated :-)
2007 CHEVROLET AVALANCHE - CHECK ENGINE LIGHT IS ON INSPECTION - MARIETTA, GEORGIA

Rodrigo

10 years of experience
85 reviews
Rodrigo
10 years of experience
Rodrigo was exactly on time, very professional and friendly. He assessed my car, let me know the exact problem when a previous mechanic from a shop in my area was unable to. I felt he was very honest and sincere letting me know the level of urgency that I deal with the issue. Absolutely no pressure. I will absolutely use Rodrigo the next time I need anything to do with my car and will tell everyone about him. This is such a great service, I will never go to another mechanic again. It is so convenient. I couldn’t be happier. :)
2013 SMART FORTWO - CHECK ENGINE LIGHT IS ON - LAS VEGAS, NEVADA

Ricardo

8 years of experience
223 reviews
Ricardo
8 years of experience
Great service and was very helpful on what maintenance my vehicle needed and what to expect in the future. Would definitely recommend to anyone and will.
2004 MITSUBISHI LANCER - CHECK ENGINE LIGHT IS ON - LOS ANGELES, CALIFORNIA

More related articles

How Long Does a Vacuum Brake Booster Check Valve Last?
The braking system on your car requires a lot of pressure. The vacuum booster is one of the main sources of this pressure. This booster will take the pressure that...
P0121 OBD-II Trouble Code: TPS "A" Circuit Range Performance Problem
P0121 code definition Throttle Pedal Position Sensor/Switch (TPS) A Circuit Range Performance Problem...
P0052 OBD-II Trouble Code: HO2S Heater Control Circuit High (Bank 2 Sensor 1)
P0052 code definition HO2S Heater Control Circuit High (Bank 2 Sensor 1) What the...

Related questions

Q: Check Engine Light does not come on even though there are trouble codes present

The pink/light green wire in ECM pin 2 on the connector will ground the wire internally to the ECM to turn on the Check Engine Light. You could test the wire with the key on and it should have battery...

Q: Hesitation, sputtering and check engine light flickering

The problems you are having may be the electrical harness intermittently loosing contact with the engine control module (ECM). The ECM may be loosing power intermittently from the main power supply. This is not a common issue; a qualified mechanic...

Q: Engine stumbles around 3000 RPM.

Hi there. The engine could be stumbling for the coil pack or distributor may not be functioning correctly. As the coil pack or distributor gets old, the parts tend to become weak and is not able to send an electrical...

How can we help?

Our service team is available 7 days a week, Monday - Friday from 6 AM to 5 PM PST, Saturday - Sunday 7 AM - 4 PM PST.

1-800-701-6230 · hi@yourmechanic.com