P0006 is an OBD-II trouble code you don’t see every day, but when it shows up, it usually points to a problem in the fuel pressure control system. While it sounds intimidating, you can understand it without being an engineer. This code deals with the electrical control side of the fuel volume regulator, not the mechanical fuel pump itself. If you’re experiencing hard starts, poor performance, or a check engine light with P0006 stored, this guide walks you through what it means, common causes, how to diagnose it, and what repairs typically cost.
What Does P0006 Mean?
P0006 stands for “Fuel Shutoff Valve ‘A’ Control Circuit Low” or, on many vehicles, “Fuel Volume Regulator Control Circuit Low.” In simple terms, your engine computer (ECU/PCM) is seeing lower-than-expected voltage or signal on the control circuit that operates a fuel shutoff valve or fuel volume regulator, usually located on or near the high-pressure fuel pump or fuel rail.
This is an electrical circuit fault, not just a fuel pressure issue. The ECU commands the valve and monitors feedback. When the return signal or circuit voltage is consistently too low, it sets P0006 and usually turns on the check engine light. Left alone, it can lead to starting problems, poor drivability, and in some cases, stalling.
Quick Reference
- Code: P0006
- Meaning: Fuel shutoff / fuel volume regulator control circuit low
- System: Fuel delivery / high-pressure fuel control
- Severity: Moderate to high (can cause no-start or stalling)
- Typical causes: Wiring faults, bad regulator/valve, poor grounds, rare PCM fault
Real-World Example / Field Notes
In the shop, I usually see P0006 on modern diesel engines and some direct-injection gas engines. One example: a late-model diesel pickup came in with long crank times and occasional stalling at idle. No fuel leak, no obvious mechanical issues. Scan tool showed P0006 and low commanded control current to the fuel volume regulator. A quick visual inspection revealed a chafed harness where it rubbed against a bracket, corroding the wires. After repairing the wiring and securing the harness, the truck started instantly and P0006 never returned.
Another case involved a direct-injection sedan with intermittent P0006 and rough cold starts. Live data and a simple voltage drop test showed a weak ground to the regulator. Cleaning and tightening the ground connection fixed the issue without replacing any expensive parts. The common theme: don’t throw a fuel pump at this code before checking the wiring and connections.
Symptoms of P0006
- Hard starting – Extended cranking, especially when the engine is cold.
- No-start condition – In more severe cases, the engine may not start at all.
- Rough idle – Unstable idle speed, shaking, or occasional misfires at idle.
- Loss of power – Poor acceleration, sluggish response, especially under load.
- Stalling – Engine may stall at stoplights or when coming off throttle.
- Check engine light – MIL illuminated with P0006 stored, possibly with related fuel pressure codes.
- Poor fuel economy – Incorrect fuel delivery can increase fuel consumption.
- Limp mode – Some vehicles limit power to protect the engine and fuel system.
Common Causes of P0006
Most Common Causes
- Damaged wiring to the fuel volume regulator / shutoff valve – Chafed, broken, or shorted wires between the ECU and the valve are the top cause. Heat, vibration, or previous repairs can damage the harness.
- Corroded or loose connectors – Moisture intrusion or poor contact at the valve connector or ECU connector can drop circuit voltage low enough to trigger P0006.
- Failed fuel volume regulator / shutoff valve – The solenoid inside the valve can short internally or draw too much current, causing a low-voltage condition on the control circuit.
- Poor ground or power supply – Weak or rusty grounds and shared power feeds can cause low circuit voltage, especially under load.
Less Common Causes
- ECU/PCM internal failure – A failed driver circuit inside the engine computer can cause a low signal, but this is rare and should be considered only after all wiring and component checks.
- Aftermarket modifications – Poorly installed remote starters, tuners, or fuel system add-ons can tap into the wrong wires and disturb the control circuit.
- Previous collision or engine work – Harness pinched between components, misrouted wiring, or missing clips after repairs can lead to intermittent shorts to ground.
- Severe corrosion from road salt or flooding – On older vehicles or those in harsh climates, widespread corrosion can affect multiple circuits, including the fuel control circuit.
Diagnosis: Step-by-Step Guide
Before you start, you’ll want a quality scan tool (preferably one that can read live data and Mode $06), a digital multimeter, basic hand tools, and access to a wiring diagram for your specific vehicle. A test light and back-probing pins are also helpful. If you’re not comfortable with electrical testing, this is a good time to involve a professional, because guessing with this code gets expensive fast.
- Confirm the code and record freeze-frame data. Connect your scan tool, confirm P0006, and note engine temperature, RPM, and fuel pressure at the moment the code set. Check for related fuel pressure or circuit codes.
- Perform a visual inspection. Locate the fuel volume regulator or fuel shutoff valve (often on the high-pressure pump or rail). Inspect the connector and harness for rubbing, melted insulation, broken clips, or corrosion. Repair any obvious damage first.
- Check connector condition. Unplug the valve and inspect pins for bent terminals, green corrosion, or spread contacts. Clean with electrical contact cleaner and ensure terminals are tight when reconnected.
- Verify power and ground. Using a wiring diagram, key on and check for proper voltage at the power feed and a solid ground at the regulator connector with a multimeter or test light. A weak or missing power/ground can mimic a bad valve.
- Test the control circuit. With the connector unplugged, check resistance between the ECU and the valve on the control wire. Look for open circuits or shorts to ground. Wiggle the harness while testing to catch intermittent faults.
- Check the regulator / valve resistance. Measure the resistance across the valve solenoid terminals and compare it to spec. A shorted or open solenoid will usually be out of range and can cause a low circuit condition.
- Monitor live data. With the engine running (if possible), look at commanded fuel pressure and actual fuel pressure, as well as any available “fuel volume control” or “regulator duty cycle” PIDs. Large differences or unstable readings support a control issue.
- Use Mode $06 and pending codes. Some vehicles provide detailed test results in Mode $06. Check for borderline test values related to fuel pressure control that may point to an intermittent circuit problem.
- Perform a wiggle test. While watching live data or the control circuit voltage, gently move the harness near the valve, along the engine, and at the ECU. If the readings jump or the engine stumbles, you’ve found a problem area.
- Evaluate the ECU last. Only after confirming good wiring, power, ground, and a known-good valve should you suspect the ECU. At this point, most shops will use a lab scope or substitute a known-good ECU to confirm.
Pro tip: On many vehicles, the same harness branch feeds multiple sensors and actuators. If you see other random circuit-low codes along with P0006, focus hard on shared grounds and splice points rather than replacing individual parts.
Possible Fixes & Repair Costs
The exact repair depends on what failed, but P0006 is usually solved with electrical work rather than major fuel system replacement. Typical repairs include:
- Repairing or replacing damaged wiring and connectors to the fuel volume regulator / shutoff valve.
- Cleaning and tightening ground connections and power feeds.
- Replacing the fuel volume regulator or fuel shutoff valve assembly.
- In rare cases, replacing or reprogramming the ECU/PCM.
Cost varies by vehicle and access. Wiring repairs can range from $100–$300 if the damage is localized. A new fuel volume regulator or shutoff valve typically runs $150–$450 parts and labor, depending on whether it’s part of the high-pressure pump. ECU replacement or reprogramming is the most expensive, often $600–$1,500. Labor time, parts availability, and how buried the component is under intake or engine covers all affect the final bill.
Can I Still Drive With P0006?
You can sometimes drive with P0006, but it’s not recommended for long. If the engine starts and runs, you may just notice hard starting or reduced power at first. However, because this code involves fuel control, it can quickly progress to stalling or a no-start situation. On some vehicles, the ECU will enter a limp mode to protect the engine, limiting power and RPM.
If you must drive, keep trips short, avoid heavy loads or towing, and monitor for worsening symptoms. If the engine begins to stall, misfire heavily, or crank without starting, have it towed rather than forcing it to run.
What Happens If You Ignore P0006?
Ignoring P0006 can leave you stranded with a sudden no-start or stall in traffic. Long-term, improper fuel control can stress the high-pressure fuel pump and injectors, potentially leading to much more expensive repairs. It also makes accurate diagnosis harder if additional codes and symptoms pile up over time.
Related Codes
- P0027 – Exhaust Valve Control Solenoid Circuit Range/Performance Bank 1
- P0026 – Intake Valve Control Solenoid Circuit Range/Performance Bank 1
- P0019 – Crankshaft Position Camshaft Position Correlation Bank 2 Sensor B
- P0018 – Crankshaft Position Camshaft Position Correlation Bank 2 Sensor A
- P0017 – Crankshaft Position Camshaft Position Correlation Bank 1 Sensor B
- P0016 – Crankshaft Position Camshaft Position Correlation Bank 1 Sensor A
- P0009 – Engine Position System Performance Bank 2
- P0008 – Engine Position System Performance Bank 1
- P0007 – Fuel Shutoff Valve “A” Control Circuit High
- P0005 – Fuel Shutoff Valve “A” Control Circuit/Open
Key Takeaways
- P0006 points to a low-voltage problem in the fuel volume regulator or fuel shutoff valve control circuit, not just a bad fuel pump.
- Most causes are electrical: damaged wiring, corroded connectors, poor grounds, or a failed valve solenoid.
- Proper diagnosis with a scan tool and multimeter is essential before replacing expensive components.
- Typical repairs range from simple wiring fixes to regulator replacement, with costs generally between $100 and $450, more if the ECU is involved.
- Driving with P0006 is risky; it can lead to stalling, no-start conditions, and potential damage to fuel system components if ignored.
Vehicles Commonly Affected by P0006
P0006 shows up most often on modern diesel trucks and SUVs that use high-pressure common-rail systems, including models from Ford (Power Stroke), GM/Chevrolet (Duramax), and Ram (Cummins). It’s also seen on some European diesels from Volkswagen, Audi, BMW, and Mercedes-Benz. Direct-injection gasoline engines from manufacturers like Ford, GM, Hyundai/Kia, and some Subaru and Mazda models can also store P0006 when the fuel volume regulator circuit has issues. While any OBD-II vehicle can technically set this code, it’s far more common on vehicles with electronically controlled high-pressure fuel systems.
FAQ
Can I clear P0006 and keep driving if the car seems fine?
You can clear the code, but if the underlying problem is still there, P0006 will almost certainly return. The car may seem fine initially, but intermittent wiring or a weak regulator can quickly turn into a hard start or no-start. Use the cleared code as a test after repairs, not as a permanent solution.
Is P0006 always caused by a bad fuel pump?
No. P0006 is usually related to the control circuit for the fuel volume regulator or shutoff valve, not the mechanical fuel pump itself. While the regulator may be mounted on the pump, most fixes involve wiring or the regulator solenoid, not replacing the entire pump. Replacing the pump without testing the circuit often wastes money.
How do I know if it’s wiring or the regulator causing P0006?
You need to test. Check for proper power and ground at the connector, measure resistance of the regulator solenoid, and verify continuity between the ECU and the valve. If wiring and power/ground are solid and the solenoid is out of spec, the regulator is likely bad. If the solenoid tests good but voltage drops or disappears along the harness, you’re dealing with a wiring issue.
Can a weak battery or charging system trigger P0006?
<pA weak battery or failing alternator can contribute to low-voltage problems, but they rarely cause P0006 by themselves. However, if system voltage drops significantly under load, it can expose marginal wiring or ground issues in the fuel control circuit. It’s smart to check battery and charging health as part of your overall diagnosis.
How urgent is it to fix P0006?
You should treat P0006 as a priority. The vehicle might still start and run today, but the risk of sudden stalling or a no-start is high. Addressing it early often keeps the repair limited to wiring or a regulator, instead of dealing with collateral damage to injectors, pumps, or getting stranded at the worst possible time.