9 OBD Codes Caused by the Fuel Pump Problem
I compiled all the possible OBD DTC codes that can be triggered by a problem related to the fuel pump. These are the possible 9 DTC you will see in your OBD diagnostic scanner. In this blog post, I included the possible cause and the possible solution to fix the problem.
9 Fuel Pump DTC Diagnostic Trouble Codes
- 0230 – Fuel Pump Primary Circuit Malfunction
- P0231 – Fuel Pump Secondary Circuit Low
- P0232 – Fuel Pump Secondary Circuit High
- P0233 – Fuel Pump Secondary Circuit Intermittent
- P025A – Fuel Pump Module Control Circuit/Open
- P0627 – Fuel Pump A Control Circuit/Open
- P0628 – Fuel Pump A Control Circuit Low
- P0629 – Fuel Pump A Control Circuit High
- P2635 – Fuel Pump ‘A’ Low Flow/Performance
P0230 – Fuel Pump Primary Circuit Malfunction
OBD DTC code P0230 is a generic powertrain code that indicates a problem with the fuel pump primary circuit. This code is often seen in vehicles that have an electric fuel pump.
Cause:
- Failed fuel pump: A fuel pump that has failed or is not functioning properly may cause the P0230 code to appear. This could be due to a mechanical failure, an electrical problem, or a clogged fuel filter.
- Faulty fuel pump relay: The fuel pump relay is responsible for providing power to the fuel pump. If the relay is faulty or not functioning properly, it can cause the fuel pump to fail and trigger the P0230 code.
- Wiring issue: A problem with the wiring in the fuel pump circuit can cause the P0230 code to appear. This could be due to a short circuit or an open circuit in the wiring.
Fix:
- Check the fuel pump: The first thing to check is the fuel pump. You can do this by using a fuel pressure gauge to check the fuel pressure. If the fuel pressure is low, it could indicate a failing fuel pump.
- Check the fuel pump relay: If the fuel pump is functioning properly, you will need to check the fuel pump relay. You can do this by checking the voltage at the relay with a multimeter. If the voltage is low or there is no voltage, the relay may be faulty and needs to be replaced.
- Check the wiring: If the fuel pump and relay are functioning properly, the next step is to check the wiring in the fuel pump circuit. Look for any signs of damage, corrosion, or loose connections. If you find any issues, repair or replace the wiring as needed.
P0231 – Fuel Pump Secondary Circuit Low
OBD DTC P0231 refers to a problem with the fuel pump secondary circuit, which is usually related to the fuel pump relay or wiring.
Cause:
- Failed fuel pump: A fuel pump that has failed or is not functioning properly may cause the P0231 code to appear. This could be due to a mechanical failure, an electrical problem, or a clogged fuel filter.
- Faulty fuel pump driver module: The fuel pump driver module is responsible for providing power to the fuel pump. If the module is faulty or not functioning properly, it can cause the fuel pump to fail and trigger the P0231 code.
- Wiring Issue: A problem with the wiring in the fuel pump circuit can cause the P0231 code to appear. This could be due to a short circuit or an open circuit in the wiring
Fix:
- Check Fuel Pump Relay: The fuel pump relay is a common culprit for P0231 codes. You can test the relay by using a multimeter or swapping it with another relay in the vehicle. If the relay is faulty, replace it.
- Check the Wiring: Check the wiring that connects the fuel pump relay to the fuel pump. Look for any signs of damage, such as frayed wires or loose connections. Repair or replace any damaged wiring.
- Check Fuel Pump: Check the fuel pump for proper function. This can be done by turning on the ignition and listening for the fuel pump to prime. If you can’t hear the fuel pump, check for power and ground at the fuel pump. If the fuel pump is faulty, replace it.
- Check the Fuel Pump Fuse: Check the fuel pump fuse to make sure it’s not blown. If it is, replace it and see if the code returns.
- Check the Fuel Pump Driver Module: If your vehicle has a fuel pump driver module, check it for proper function. The fuel pump driver module controls the fuel pump operation. If it’s faulty, replace it.
- Clear the Code: After you have fixed the issue, clear the code using an OBD scanner or by disconnecting the battery for a few minutes.
P0232 – Fuel Pump Secondary Circuit High
Cause:
- The most common cause of this code is a faulty fuel pump relay. The relay may be stuck closed, causing the fuel pump to continue running even when the ignition is turned off. Other possible causes include a short circuit in the fuel pump wiring, a failed fuel pump, or a malfunctioning PCM.
Fix:
- To fix this issue, you should start by checking the fuel pump relay. If the relay is stuck closed, you may need to replace it. You can also check the wiring and connectors in the fuel pump circuit for signs of damage or corrosion. If you find any issues, you may need to repair or replace the affected components.
If the fuel pump and fuel pump relay are both functioning properly, the issue may be with the PCM. In this case, you may need to take your vehicle to a qualified mechanic for further diagnosis and repair. They may need to replace the PCM or perform other repairs to resolve the issue.
P0233 – Fuel Pump Secondary Circuit Intermittent
OBD DTC code P0233 indicates a problem with the fuel pump secondary circuit intermittent voltage. Specifically, it means that the powertrain control module (PCM) has detected an intermittent voltage reading in the fuel pump secondary circuit that is outside of the normal range.
Cause:
- The most common cause of this code is a failed fuel pump relay. The relay may be stuck open or have an internal short circuit, which prevents the fuel pump from receiving the proper voltage. Other possible causes include a damaged fuel pump wiring harness or a failed fuel pump driver module.
Fix:
- To fix this issue, you should start by checking the fuel pump relay. If the relay is found to be faulty, it should be replaced. You can also check the wiring and connectors in the fuel pump circuit for signs of damage or corrosion. If you find any issues, you may need to repair or replace the affected components.
P025A – Fuel Pump Module Control Circuit/Open
The OBD DTC code P025A refers to an issue with the fuel pump module control circuit. This code is set when the engine control module (ECM) detects a fault in the fuel pump control module circuit.
Cause:
- The issue with the fuel pump control module
- Faulty fuel pump driver circuit
- A malfunctioning fuel pressure sensor
- Wiring and connection issues in the fuel pump control module circuit
- The issue with the fuel pump
Fix:
- Check the wiring and connections in the fuel pump control module circuit for any damage, corrosion, or loose connections.
- Check the fuel pressure sensor for proper operation and replacement if necessary.
- If the wiring and connections are good and the fuel pressure sensor is working, test the fuel pump driver circuit for any faults.
- If the fuel pump driver circuit is faulty, replace the fuel pump control module.
- If the fuel pump control module is functioning properly and the wiring, connections, fuel pressure sensor, and fuel pump driver circuit are all okay, the fuel pump may need to be replaced.
P0627 – Fuel Pump A Control Circuit/Open
This code is set when the powertrain control module (PCM) detects an issue with the fuel pump control circuit, which could cause a malfunction in the fuel delivery system.
Cause:
- Faulty fuel pump control module or a damaged wiring or connector in the fuel pump control circuit. Other possible causes include a failed fuel pump relay, a blown fuse, or a malfunctioning PCM.
Fix:
- Start by checking the fuel pump control module and the wiring and connectors in the fuel pump control circuit. You should also check the fuel pump relay and fuses to make sure they are functioning properly. If the problem is not with any of these components, it may be a malfunctioning PCM, which should be diagnosed and repaired by a qualified technician.
P0628 – Fuel Pump A Control Circuit Low
The DTC code P0628 refers to a problem with the fuel pump control circuit. Specifically, it indicates that the PCM (powertrain control module) has detected a low voltage condition in the fuel pump control circuit.
Cause:
- Failed fuel pump: A failing or faulty fuel pump can cause the voltage in the fuel pump control circuit to drop, triggering the P0628 code.
- Wiring issues: A short circuit or an open circuit in the wiring that connects the fuel pump to the PCM can cause the voltage to drop and trigger the code.
- Failed fuel pump relay: A faulty fuel pump relay can also cause the voltage in the fuel pump control circuit to drop, resulting in the P0628 code.
- Failed PCM: Although rare, a failed PCM can cause the P0628 code to appear.
To diagnose the exact cause of the P0628 code, a mechanic may use a scan tool to check the voltage in the fuel pump control circuit, and then proceed to check the fuel pump, wiring, and relay to determine which component is causing the issue.
Fix:
- Replace the fuel pump: If the fuel pump is the cause of the problem, it will need to be replaced.
- Repair or replace damaged wiring: If there is a short circuit or an open circuit in the wiring that connects the fuel pump to the PCM, it will need to be repaired or replaced.
- Replace the fuel pump relay: If the fuel pump relay is faulty, it will need to be replaced.
- Repair or replace the PCM: If the PCM is the cause of the problem, it may need to be repaired or replaced. This is a rare occurrence, and should only be considered after ruling out all other possible causes.
It’s important to note that diagnosing and repairing the underlying cause of the P0628 code can be a complex and potentially dangerous process. It is recommended to have a qualified mechanic diagnose and repair the issue to ensure that the repair is performed correctly and safely
P0629 – Fuel Pump A Control Circuit High
OBD DTC P0629 is related to the fuel pump control circuit. This indicates that there is an issue with the fuel pump control circuit, specifically an issue with the fuel pump control module.
When this module fails, it can cause a range of issues, including a no-start condition or intermittent stalling.
Cause:
- Some common causes include a faulty fuel pump control module, a short circuit or open circuit in the fuel pump control circuit, or a problem with the fuel pump relay. A malfunctioning battery or alternator can also cause this issue.
Fix:
- To fix the P0629 code, the first step is to diagnose the cause of the issue. This is typically done using a code scanner to read the code and any other code that may be present. A technician may also perform a visual inspection of the fuel pump control circuit and check the fuel pump relay for proper operation.
- Once the cause of the issue has been identified, appropriate repairs can be made. This may involve replacing the fuel pump control module, repairing any damaged wiring, or replacing the fuel pump relay. In some cases, it may be necessary to replace the fuel pump itself.
- After the repairs have been made, the code should be cleared from the vehicle’s memory using a code scanner. The vehicle should then be test-driven to ensure that the issue has been resolved.
P2635 – Fuel Pump ‘A’ Low Flow/Performance
Diagnostic Trouble Code (DTC) P2635 indicates a problem with the fuel pump ‘A’ in the fuel delivery system. The fuel pump ‘A’ is responsible for supplying fuel from the fuel tank to the engine, and a low flow or poor performance from this pump can cause a variety of issues with the engine’s performance.
Cause:
- Clogged fuel filter: A clogged fuel filter can restrict the flow of fuel to the engine, causing the fuel pump to work harder to deliver the necessary fuel.
- Faulty fuel pump: A malfunctioning fuel pump can also cause low flow or poor performance. This can be due to a variety of issues, such as a faulty motor, a blocked fuel line, or a worn-out pump.
- Wiring issue: Faulty wiring in the fuel pump circuit can cause low voltage to the pump, resulting in poor performance or low flow.
- Fuel pressure regulator problems: A malfunctioning fuel pressure regulator can cause low fuel pressure, leading to poor fuel flow and performance issues.
Fix:
- To diagnose the issue, a mechanic will typically perform a series of tests, including fuel pressure tests and inspections of fuel filters and fuel lines. Once the root cause of the problem is identified, the mechanic will typically replace the faulty component, such as the fuel pump or fuel filter, and then clear the DTC from the vehicle’s computer.
Above are lists of all possible diagnostic trouble codes related to the fuel pump problem that you may encounter during an OBD scan. Thank you very much for visiting my website. –Erwin C. Salarda