P0006
PowertrainFuel Shutoff Valve "A" Control Circuit Low
The fuel shutoff valve is the solenoid that controls whether fuel can reach the injection system, and on diesels it's what actually kills the engine when you turn the key off. P0006 means the ECM is seeing too little voltage on the wire that controls that valve, so it can't trust the valve to do its job. You'll usually see this on common-rail diesels and stop-start cars rather than ordinary petrols. Left alone, the engine can struggle to start, run rough, or in some cases keep running after you've switched off.
ⓘ Information only. This page provides general educational information about fault code P0006. We do not assess the urgency or safety implications of any specific fault. That requires in-person diagnosis by a qualified mechanic. Full terms.
Recommended next steps
Whether a fault is urgent, drivable, or routine depends entirely on the cause on a specific vehicle, and that can only be determined by a qualified mechanic with diagnostic equipment. If a warning light is illuminated, the most reliable next step is professional diagnosis.
What does P0006 mean?
P0006 is a Powertrain (engine, transmission, fuel system) fault code. It indicates: Fuel Shutoff Valve "A" Control Circuit Low.
This is a standardised OBD-II code. The technical definition is the same regardless of the make or model of vehicle, although specific causes and symptoms can vary between vehicles.
Symptoms commonly associated with this code
Symptoms that drivers often report alongside this code. Not all may apply to every case:
- • Engine warning light on the dash, sometimes the only sign anything's wrong
- • Engine carries on running for a second or two after you turn the ignition off (old-school 'dieseling')
- • Hard starting or the engine cranking but not catching because fuel pressure won't build
- • Lumpy idle or the occasional unexplained stall
- • Down on power and slow to respond to the throttle
- • Fuel economy creeping in the wrong direction
Possible causes
Causes commonly associated with P0006, listed in approximate order of typical investigation. The actual cause on a specific vehicle can only be confirmed by professional diagnosis.
- 1. Corroded or loose connector at the valve itself. Diesel solenoids live in a hot, dirty part of the engine bay and the pins suffer for it
- 2. Chafed or broken wire in the harness between the ECM and the valve, often where the loom rubs on a bracket or rounds an edge
- 3. Water getting into the connector and bridging the pins, which drags the voltage reading down
- 4. The shutoff solenoid itself failing with an internal short or open winding
- 5. Low system voltage from a tired battery or a charging fault, which the ECM can misread as a valve problem
- 6. ECM driver stage gone faulty so it can't put the right voltage out. Least common, but it happens
How mechanics typically diagnose
A typical diagnostic sequence used by mechanics, provided here for educational reference only. Diagnostic work should be performed by a qualified mechanic with the appropriate tools and training.
- 1. Read all stored codes, not just P0006. Fuel-pressure and other shutoff-circuit faults usually travel together and point you straight at the cause
- 2. Check battery and charging voltage first: 12.4 to 12.8V engine off, 13.8 to 14.4V running. A weak battery throws all sorts of low-voltage codes and wastes your time if you skip it
- 3. Unplug the valve connector and look hard at the pins for green corrosion, spread terminals, or any sign of damp. This is where the fault hides on most diesels
- 4. Key on, engine off, back-probe the connector and confirm the ECM is actually supplying voltage to the valve
- 5. Do a continuity and resistance check on the control wire from ECM to valve to catch a broken or high-resistance conductor
- 6. If the wiring and supply both check out, measure the solenoid's resistance against spec or substitute a known-good unit before condemning the valve
Common questions about P0006
What am I looking at to get this sorted, independent versus a main dealer? +
If it's just a corroded connector or a chafed wire, a good independent will sort it for low three figures, mostly labour for tracing and repairing the loom. A new shutoff solenoid plus fitting tends to land in the mid three figures depending on how awkward it is to reach. The expensive end is if the ECM driver has failed and the module needs replacing or coding, which at a main dealer can run into the high three figures. Get the wiring checked properly before anyone sells you an ECM.
How do I work out which of these is actually wrong on my car? +
Start with the cheap stuff. Sort the battery and charging voltage first, because a flat or failing battery alone can set this. Then unplug the valve connector and inspect it: corrosion or moisture on the pins is the single most common culprit on diesels and is obvious once you're looking. If the connector's clean, do the continuity test on the control wire to find a break, then test the solenoid's resistance. The ECM is only suspect once wiring, supply, and the valve all read good.
Can I have a go at this myself? +
Some of it, yes. Cleaning a corroded connector with contact cleaner and reseating it is well within reach if you can get to it, and that fixes a fair share of these. Checking battery voltage with a multimeter is easy too. Where it gets beyond a driveway job is tracing a wiring fault through the loom or replacing a solenoid buried under fuel-system parts, and anything touching the ECM needs a workshop with the right kit to diagnose and code it.
Information only, not professional advice
The information on this page is provided for general guidance and educational purposes only. It is not a substitute for diagnosis or repair advice from a qualified mechanic. Always verify any fault before paying for repairs. carfaultcodes.co.uk accepts no liability for decisions made based on this information. Full terms →