P0660
PowertrainIntake Manifold Tuning Valve Control Circuit/Open Bank 1
Most of the time this comes down to the wiring or connector at the intake manifold tuning valve playing up, not the valve itself. The ECU watches the control circuit for that valve on bank 1, and when it sees an open circuit or a voltage that doesn't add up, it logs P0660. The tuning valve alters the length of the intake runners to suit engine speed, so when the control side drops out, the engine can feel a bit flat and the warning light comes on.
ⓘ Information only. This page provides general educational information about fault code P0660. 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 P0660 mean?
P0660 is a Powertrain (engine, transmission, fuel system) fault code. It indicates: Intake Manifold Tuning Valve Control Circuit/Open Bank 1.
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:
- • Check engine light on, usually the first thing you notice
- • Rough or lumpy idle, worst from cold
- • A flat spot or hesitation when you put your foot down
- • Power tails off at higher revs where the runner switching normally helps
- • Fuel economy creeps up, often 5-10% on a regular commute
- • Faint clicking or ticking from the inlet area, or none at all if the valve has stopped moving
Possible causes
Causes commonly associated with P0660, listed in approximate order of typical investigation. The actual cause on a specific vehicle can only be confirmed by professional diagnosis.
- 1. Damaged or corroded wiring and connector pins at the valve, the cheapest and most common reason for this code to appear
- 2. Poor connection at the plug, broken locking tab or moisture getting in over time
- 3. Stuck or failed tuning valve, the plastic ones don't love heat cycling and can seize
- 4. Open or shorted solenoid control wiring between the ECU and the valve
- 5. Vacuum leak upsetting how the valve operates on vacuum-actuated setups
- 6. Carbon build-up or a jammed intake runner stopping the flaps moving freely
- 7. ECU driver fault, rare, only worth considering once everything else checks out
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. Pull all stored codes and the freeze frame data. P0660 rarely turns up alone, and any P0661 to P0663 or runner-position codes alongside it point you straight at the problem
- 2. Unplug the valve connector and have a proper look. Green corrosion, a snapped tab, melted plastic or oil in the plug is your answer most of the time
- 3. Check continuity and resistance through the harness from the ECU to the valve, you want a clean reading around 100 ohms or less with no breaks
- 4. Use a scan tool active test to command the valve open and shut, and listen for a clean click. Silence means the valve or its feed isn't responding
- 5. Test the supply voltage and current at the valve when energised, typically a 30 to 50 mA draw. Nothing there sends you back up the wiring
- 6. If the wiring, connector and supply all pass, the valve itself is the suspect and worth removing for a look
Common questions about P0660
What am I risking if I just leave it? +
You won't blow the engine up tomorrow. The car will run with less poke up top and drink a touch more fuel, and the light stays on. The real downside is a stuck runner valve can cause uneven running that triggers misfire codes over time, so a P0660 left for months can turn into a longer fault list. If it's only the wiring, it's even less dramatic, but the light won't clear itself.
How quickly do I need to sort it? +
Not an emergency in most cases. If the car is idling rough enough to stall or it's dropped into limp mode, get it looked at within a few days because driving a stalling car in traffic isn't safe. If it's just a light and a slightly soft top end, you've got a couple of weeks to book it in without doing harm.
Is it the valve gone bad or just the wiring? +
On this code the wiring and connector are the first thing to suspect, since the fault is about the control circuit rather than the valve mechanically failing. Corroded pins, a cracked connector or a chafed wire near the manifold sets it off plenty. A failed valve does happen, but you confirm that only after the harness and connector come back clean. Don't buy a valve before you've tested the plug.
How long does the repair take? +
A wiring or connector repair is often an hour or so if the damage is easy to reach. Swapping the tuning valve depends on the engine, some sit right on top and take under an hour, others are buried under the intake and run to two or three hours of labour. ECU replacement is the long one because it needs programming, but that's a rare outcome and you'd want a second opinion before going there.
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 →