P0661 Intake manifold tuning valve: signal or voltage too low (bank 1)

By: Diagno editorial team · Updated: 2026-10-15

P0661 means: Intake manifold tuning valve: signal or voltage too low (bank 1). The intake manifold has swirl or runner flaps that help the engine breathe better at different revs. Drive gently and have the car checked soon. The most common repair costs about €45–90 in Estonia, depending on make and model.

What it means

The intake manifold has swirl or runner flaps that help the engine breathe better at different revs. The computer found that the flaps don't move correctly or their sensor is faulty. The signal voltage is too low. Usually a wire is broken, a connector is loose or a wire is shorted to ground.

What you may notice

• Engine light on
• Less power at certain revs
• Idle may be uneven

What could be wrong

1. 1Connector loose, damp or corroded · Wiring or connector repair €45–90
2. 2Wire broken or shorted to ground · Wiring or connector repair €45–90
3. 3Faulty actuator or sensor · Sensor replacement €80–160
4. 4Engine computer fault (rare) · Control unit check and software €150–300

Repair difficulty: Moderate

What you can check yourself

First look at the connector and wiring: anything loose, melted or green with corrosion? On some engines a flap can break off and fall into the engine, so don't put this off for long. Best left to a workshop. It needs a diagnostic tool and experience.

How we fix it

1. We read the fault data on the diagnostic tool and check whether the fault is constant
2. We measure the circuit's supply, ground and signal
3. We repair the wire or replace the connector
4. If the wiring is fine, we replace the actuator or sensor

Standard SAE description: Intake Manifold Tuning Valve Control Circuit Low Bank 1