The P0629 trouble code indicates that the fuel pump “A” control circuit is experiencing high voltage. This circuit is responsible for controlling the operation of the fuel pump, which delivers fuel from the fuel tank to the engine.
P0629 Fuel Pump “A” Control Circuit High
Code symptoms P0629.
1. Check Engine Light (CEL) illuminated on the dashboard.
2. Vehicle may not start or experience difficulty starting.
3. Fuel pump may run continuously or erratically.
4. Engine may run rich or lean.
5. Potential damage to the fuel pump and related components due to overvoltage.
This code is common in brands such as:: Chevrolet, Renault, Ford, Toyota, Nissan, Mercedes Benz, Honda.
Causes of the code P0629.
1. Faulty fuel pump.
2. High voltage in the fuel pump “A” control circuit.
3. Corroded or loose connectors in the fuel pump circuit.
4. Faulty fuel pump relay.
5. Defective fuel pump control module.
6. Battery voltage too high.
7. Charging system malfunction.
Code Solutions P0629.
1. Check the battery voltage and charging system to ensure they are within normal operating range. Replace the alternator or voltage regulator if necessary.
2. Inspect the wiring and connectors associated with the fuel pump “A” control circuit for any signs of damage, corrosion, or looseness. Repair or replace wiring and connectors as needed.
3. Test the fuel pump to ensure it is functioning properly. Replace if necessary.
4. Test the fuel pump relay for proper operation. Replace the relay if it is faulty.
5. Check the fuel pump control module for proper function. Replace if necessary.
6. Clear the trouble codes and test drive the vehicle to see if the P0629 code returns. If it does, further diagnosis may be necessary.