OBD2 code P0002 is associated with the “Fuel Volume Regulator Control Circuit Range/Performance,” indicating a problem with the fuel volume control system that affects the regulation of fuel to the engine.
This code can manifest in various ways, including low fuel pressure at startup, delayed startup, or performance issues during acceleration. It’s essential to address this code promptly, as it directly impacts engine performance and efficiency.
P0002 quick overview
| Meaning | P0002: Fuel Volume Regulator Control Circuit Range/Performance |
| Is it serious? | Yes, it can lead to engine performance issues and potentially strand you with a non-starting vehicle. |
| Possible causes | – Faulty fuel volume regulator – Issues with the fuel pump or fuel pressure regulator – Clogged or leaking fuel injectors – Wiring or electrical problems related to the fuel system – Faulty fuel pump control module |
| How to diagnose? | Inspect the fuel volume regulator for proper operation and signs of wear or damage. Check the fuel pump and fuel pressure regulator for any faults that might be causing low fuel pressure. Perform a fuel pressure test to accurately diagnose issues with the fuel system, particularly during cold starts or acceleration. Inspect fuel injectors for clogs or leaks that could affect fuel delivery. Evaluate the wiring and electrical connections related to the fuel system, including the fuel pump relay and fuel pump control module. Consider the engine’s coolant temperature sensor, as it can influence fuel delivery, especially during cold starts. |
P0002 Meaning
When you encounter the P0002 code, it’s like the fuel system’s conversation with the engine is getting lost in translation, leading to issues like delayed starts or a lack of power when you need it most. This code could point to anything from a hiccup in the fuel pump’s work to deeper troubles with how fuel is regulated and delivered.
Because the fuel system is like the heart of your vehicle, pumping vital energy to the engine, any discrepancies in its operation can lead to noticeable impacts on your driving experience. It’s a signal to dive under the hood (sometimes quite literally) and check out the vital components ensuring your car runs smoothly and efficiently.
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How to fix P0002 – learn from mechanics
I looked into P0002 service cases at iatn.com website where in the private forums the mechanics seek advice from other mechanics. I looked up a bunch of cases to help you decide how to fix your issue and see what would a real mechanic do to solve it.
Case #1: Mercedes P0002
Vehicle information 2013 Mercedes-Benz C250 1.8L
Issue + repair history
- Deep clanging, harmonics sound from upper side, back of the engine
- No change in engine performance, starts fine
- Sound increases with RPM
- Head gasket and timing chain recently replaced
- No timing codes present
- Current code: P0002 related to low fuel pressure at startup and delayed startup
- Removing oil cap while running doesn’t increase sound volume, indicating it’s not timing chain or valve train related
Other OBD2 Codes + Test Results
- P0002: Low fuel pressure at startup and delayed startup
Mechanic suggestions
- Suggested eliminating piston and/or cylinder wall damage by inspecting the bores after removing spark plugs
- Recommended capturing an ignition pattern on one cylinder at a time to see if the sound is in time with any individual pattern captures
- Advised using a video scope to inspect inside each cylinder for mechanical issues
- Proposed checking the condition of cam adjusters, the high-pressure fuel pump, and lifter for any issues
- Suggested running the engine with one spark plug removed to observe if the noise changes
- Recommended conducting a manual compression and leakdown test to verify the engine’s mechanical condition
- Speculated that the issue could be caused by a nut or bolt on top of a piston, carbon buildup on top of the piston contacting the head, or a broken or loose flex plate or foreign object in the flex plate converter area
- Advised inspecting the timing chain for stretching as it’s a common issue on 1.8L engines
Final fix Inspecting the cylinders revealed no damage, but bearing debris was found inside the oil filter. Tearing down the motor indicated likely double tapping of piston pins or the piston contacting the cylinder head. Disconnecting coils, especially number 4, reduced the noise.
Case #2: Toyota P0002
Vehicle information 2010 Toyota Camry LE 2.5L
Issue + repair history
- Engine making a rattling noise during acceleration
- No noticeable change in engine performance
- Recent repairs: replaced spark plugs, ignition coils, and fuel filter
- No visible signs of damage under the hood
Other OBD2 Codes + Test Results
- P0002: Low fuel pressure at startup and delayed startup
Mechanic suggestions
- Suggested checking the fuel pump and fuel pressure regulator for any issues
- Recommended performing a fuel pressure test to diagnose the problem accurately
- Advised inspecting the fuel lines and connections for leaks or blockages
- Speculated that the issue could be caused by a faulty fuel pump relay or wiring issue
- Proposed resetting the fuel system adaptation values using a scan tool to see if it resolves the problem
Final fix After performing a fuel pressure test, it was discovered that the fuel pump was operating below the recommended pressure. Replacing the fuel pump resolved the P0002 code and eliminated the rattling noise during acceleration.
Case #3: Honda P0002
Vehicle information 2015 Honda Civic LX 1.8L
Issue + repair history
- Engine occasionally struggles to start, especially in cold weather
- No noticeable performance issues while driving
- Recent repairs: replaced battery and cleaned throttle body
- No visible signs of damage in the engine bay
Other OBD2 Codes + Test Results
- P0002: Low fuel pressure at startup and delayed startup
Mechanic suggestions
- Suggested checking the fuel pump and fuel pressure regulator for any issues
- Recommended performing a fuel pressure test during cold starts to diagnose the problem accurately
- Advised inspecting the fuel injectors for any clogs or leaks that could affect fuel delivery
- Speculated that the issue could be caused by a faulty fuel pump control module or wiring issue
- Proposed checking the engine coolant temperature sensor to ensure it’s functioning correctly
Final fix After conducting a fuel pressure test during cold starts, it was observed that the fuel pressure was lower than normal. Replacing the fuel pump control module resolved the P0002 code and improved cold-start performance.
How to diagnose P0002
I made you an overview of solving this DTC, based on all the advice that was suggested by certified mechanics to address this issue in previously mentioned service cases.
| Diagnostic Step | Brief Explanation |
|---|---|
| Inspect the fuel volume regulator | Check for signs of malfunction or damage that could affect fuel regulation |
| Check the fuel pump and fuel pressure regulator | Identify issues causing low fuel pressure, critical for proper engine startup and performance |
| Perform a fuel pressure test | Diagnose fuel system performance, especially during specific conditions like cold starts or acceleration |
| Inspect fuel injectors | Ensure they are delivering fuel efficiently without clogs or leaks |
| Evaluate wiring and electrical connections | Look for any issues that could impair the fuel system’s electrical signals |
| Check the engine coolant temperature sensor | Verify it’s accurately measuring engine temperature, which affects fuel delivery |
Car Diagnostics Training
- Car Electrical basics
- OBD-II scanner basics
- How to use an OBD reader
- Introduction to a Bi-directional Scan tool
- OBD scanner buyer’s guide + discounts
I test OBD-II scanners and make DIY Engine diagnostics guides to help you solve your car problems without having to depend on the mechanic. A lot of them will try to scam you or are just no help at all. About Juraj Lukacko