P2016–P2021 Intake Manifold Runner Position Sensor/Switch Circuit Low Bank 1
The voltage on this circuit is sitting near zero. Typically a short to earth, or a sensor that has failed to its low end.
Can you drive it? The engine light will stay on and the car may run in a reduced-power mode. Read the freeze-frame data to see the conditions the fault was logged under.
Which code is which
Same fault, different cylinder or bank — diagnosed the same way. Several set together usually means one shared cause.
| Code | Definition | Severity |
|---|---|---|
P2016 | Intake Manifold Runner Position Sensor/Switch Circuit Low Bank 1 | Investigate soon |
P2021 | Intake Manifold Runner Position Sensor/Switch Circuit Low Bank 2 | Investigate soon |
The definition
P2016: Intake Manifold Runner Position Sensor/Switch Circuit Low Bank 1.
P2016 is a manufacturer-specific powertrain code (the engine or gearbox). Its meaning is set by the carmaker rather than by the SAE standard, so a generic OBD-II reader will often show it as an unknown code or misread it.
What to check first
Cheapest and fastest checks first:
- Unplug the sensor. If the reading jumps to full scale, the wiring is fine and the sensor has failed low.
- Check the sensor's 5V supply and its earth before condemning the sensor itself.
What actually causes this on a VAG
This one is about the position feedback from the intake manifold flaps, not about the flaps themselves. The ECU has a sensor telling it where the flap shaft is sitting, and the signal has fallen below anything it considers physically possible - so it's an electrical complaint: a short to earth, a break, or a lost reference supply. On most VAG engines this sensor isn't a separate part at all; the flap position potentiometer is built into the flap actuator motor on the manifold, and the two are only sold together. The flaps may well be working perfectly.
Most likely causes, in order
- Connector and wiring at the actuator. The plug sits on top of a hot manifold in an oily part of the engine bay, so chafed wiring, corroded pins and oil or water creeping into the connector are all common. Unplug it and look for green or spread terminals and damp inside, check the retaining clip is properly latched, then wiggle the loom with live data on screen.
- A shared supply or earth problem. These sensors run off a reference supply shared with other sensors on the engine. If several unrelated sensors have thrown implausible-signal or circuit codes at the same time, chase the common supply or earth point rather than replacing individual parts - it's a great deal cheaper than the actuator.
- The actuator and sensor unit itself. The sensor track inside the module wears and starts reporting nonsense. If the wiring and the supply check out at the plug, this is the next step, and on these engines it's replaced as a complete motor-and-sensor unit rather than as a sensor.
Worth knowing: Because the sensor isn't sold separately from the flap motor - and on some VAG manifolds the motor isn't sold separately from the manifold either - there's nothing cheap to swap here, so be genuinely thorough with the plug, the loom and the supply before spending. Two other things worth knowing: if you've also got a 'stuck open' or 'stuck closed' flap code stored, deal with this electrical fault first, because the ECU can't judge what the flaps are doing while it isn't getting a believable signal from them; and on VAG the code that turns up far more often on these flap systems is P2015, the implausible-signal one, which usually points at the broken plastic lever on the actuator rather than at wiring.
Reading the code is the easy part
A code names the circuit that complained. What tells you why is watching the sensor behind it while the engine runs — and that is where a code reader stops and a diagnostic tool starts.
VAGPULSE reads every module in a VW, Audi, Skoda or SEAT — not just the engine — shows the live measuring blocks behind this fault, gives you the freeze-frame conditions it was logged under, and clears it once you have fixed it. It also does what a generic OBD reader cannot on a VAG: service resets, coding, adaptations, and Stage 1–3 flashing with your original file saved first.
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Common questions
What does P2016 mean?
P2016 means Intake Manifold Runner Position Sensor/Switch Circuit Low Bank 1. The voltage on this circuit is sitting near zero. Typically a short to earth, or a sensor that has failed to its low end.
Can I drive with P2016?
The engine light will stay on and the car may run in a reduced-power mode. Read the freeze-frame data to see the conditions the fault was logged under.