The P0629: Fuel Pump ‘A’ Control Circuit High code indicates that the control module has detected a high voltage in the fuel pump ‘A’ control circuit. This issue can be caused by a faulty control circuit, high voltage in the system, or wiring problems, potentially leading to improper fuel delivery and engine performance issues.
P0629 – Quick Overview
| Code | Information |
|---|---|
| Meaning | P0629: Fuel Pump ‘A’ Control Circuit High |
| Is it serious? | Yes, it can affect fuel delivery, causing engine performance issues. |
| Possible causes | – Faulty fuel pump control circuit – High voltage in circuit – Wiring issue |
| How to diagnose? | – Test fuel pump control circuit for voltage – Inspect wiring and connectors – Replace fuel pump or control circuit if necessary |
P0629 Meaning
The P0629 code indicates that the voltage in the fuel pump ‘A’ control circuit is higher than expected. This can lead to the fuel pump receiving excess power, potentially causing over-delivery of fuel or affecting fuel pressure, which may result in engine performance problems like poor acceleration, stalling, or rough idling.
Step-by-step diagnostic guide
| Action | Description | Tools Needed |
|---|---|---|
| Check for Other Codes | Use an OBD-II scanner to check for additional codes related to the fuel or electrical system that might provide further context. | OBD-II Scanner |
| Test the Fuel Pump Control Circuit for Voltage | Use a multimeter to measure the voltage in the fuel pump control circuit and verify that it is within the specified range. | Multimeter |
| Inspect Wiring and Connectors | Inspect the wiring and connectors linked to the fuel pump control circuit for signs of damage, loose connections, or corrosion. | Flashlight, Multimeter |
| Test the Fuel Pump | If the control circuit shows high voltage, test the fuel pump to ensure it is functioning properly and not drawing excess power. | Diagnostic Tool, Multimeter |
| Replace the Fuel Pump or Control Circuit if Necessary | If the fuel pump or control circuit is faulty, replace the component(s) to restore proper fuel system function. | Replacement Fuel Pump/Parts |
| Clear the Code and Test | After completing repairs, clear the code using an OBD-II scanner and test the vehicle to ensure that the fuel pump is working properly. | OBD-II Scanner, Vehicle Manual |
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