What Codes Will This Page Cover?
This page will cover the following:
- P0231 – Fuel Pump Secondary Circuit Low
- P0232 – Fuel Pump Secondary Circuit High
- P0233 – Fuel Pump Secondary Circuit Intermittent
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What Is the P0231 Code?
Symptoms
Causes
Seriousness
Can I Still Drive?
Diagnose
Difficulty of Inspecting
Get Additional Help
These codes relate to the fuel pump relay circuits, which are a part of the fuel pump system. These OBD-II codes pertain to your fuel pump or fuel pump relay. It may be necessary to replace the fuel pump relay and the fuel pump if there are lingering issues.
The powertrain control module (PCM) is responsible for monitoring and controlling the fuel system to ensure adequate fuel pressure to the engine. Some vehicles have a feedback relay circuit that signals the PCM on the status of the voltage supplied to the fuel pump to confirm adequate fuel flow.
If the PCM detects little to no voltage returned from the fuel pump feedback circuit, then code P0231 is set, and the check engine light is illuminated. Code P0232 means that the returned voltage signal is higher than normal, while code P0233 appears intermittently when the signal is received.
More about P0231, P0232, and P0233 codes
All these codes represent different voltage states of the fuel pump signal relay. Here’s what sets codes P0231, P0232, and P0233 apart:
- P0231: Fuel Pump Secondary Circuit Low – A voltage signal that is too low or no voltage at all
- P0232: Fuel Pump Secondary Circuit High – A high voltage signal when the fuel pump isn’t activated
- P0233: Fuel Pump Secondary Circuit Intermittent – An intermittent voltage signal problem when the fuel pump isn’t activated
These OBD codes help you determine where the problem is as well as whether there is a low, high, or intermittent voltage issue. Not all car manufacturers adopt these definitions, so it’s critical to look at the car code for your specific vehicle as well as test the glow plug circuit.
What Are the Symptoms of a P0231 Code?
P0231, P0232, and P0233 all have similar symptoms. Common ones are reduced engine performance, a non-starting engine, stalling or misfiring while on the road, and an illuminated Check Engine Light. These symptoms are manifestations of a fuel pump problem. P0232 and P0233 codes can also present with a running fuel pump even if the key is off.
What Are Some Causes of a P0231 Code?
These codes usually mean that there is a fault in the fuel pump relay where erratic voltage signals are being sent to the PCM. The harness leading to the fuel pump could also be damaged, causing too much resistance due to corrosion, an open wire, or a partially exposed circuit that is touching the body or chassis of the vehicle. The feedback circuit to the PCM could also be damaged, making the PCM shut off the pump relay because it is not receiving the right feedback. Other issues include broken connectors, blown fuses, or a defective fuel pump or PCM.
How Serious Is the P0231 Code?
Because these codes point to a faulty fuel pump system, it can lead to severe engine problems if not addressed immediately. The engine will be damaged over time because of inconsistent fuel supply from the pump.
Can I Still Drive with a P0231 Code?
You might not be able to even start your car, let alone drive it. Even if the engine starts, stalling and misfires can repeatedly occur, which are a safety hazard for both you and the other vehicles on the road. It is not recommended to use the car if any of these codes are present.
How Easy Is It to Diagnose a P0231 Code?
If you have the right tools and knowledge, then diagnosing P0231, P0232, and P0233 codes should be moderately easy to sort out. Diagnosing fuel pump circuits may require a good wiring diagram before trying repairs. Always do a visual inspection for frayed harnesses and broken connectors before going further into the electrical issues.
How Difficult Is It to Inspect a P0231 Code?
Electrical problems can be a challenge for even the most qualified mechanics. Low voltage issues that stem from a P0231 code can be hard to pinpoint unless you have the right equipment and a detailed wiring diagram available. Simply replacing components of the fuel pump system may not be enough to solve the problem.
Need Additional Help with Your P0231 Code?
Fuel pump issues are a major problem for your car and require immediate attention from a qualified expert. Faulty components related to the fuel pump will lead to engine failure. Find a reputable mechanic or shop to help you fix these problems quickly.
Use Kelley Blue Book to find a repair shop in your area. This makes fixing your car easier and more convenient, no matter what the problem may be.
If you are a DIY mechanic who wants to learn more about error codes and how to fix them, then the KBB OBD-II database provides detailed information that could help you better understand your car.
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