Recently I had experienced a Check Engine on 2012 VolksWagen Passat, and the error code was P0106. After quick research I found that I can replace the Map Sensor as well as the PCV Valve. Both together were about $50 or $60 in the local autopart store.

During the Map Sensor replacement process, I removed the Throttle Body and cleaned it with brake cleaner spray. However, I did notice that the throttle plate does not close/snap all the bad to a perfect fit. Also, I noticed a whole lot of black (grease?) that could potentially be a long term accumulation of air (similar to how the black carbon accumulated in the throttle body and plate?).

I am wondering, as the throttle plate is spring loaded, and does not close/snap all the way, does the on-board computer align the closure for a good seal? Or does it have to be done manually by the OBDII?

In one of the replacement YouTube videos, the good fella did use VCDS to adapt the throttle body. I do not have VCDS and only have three cheap OBDII dongles (Carista, Autel AutoLink AL319, Foseal), but I do not believe they can adapt the throttle body.

Question is, after the Map Sensor and PVC Valve repalcement - the car is driving just fine, and the error has not come back yet. But is it alright to have the spring-loaded throttle body not close all the way? Also, any recommendation to a DIY to align the throttle body? Or make sure that the throttle-plate closes properly?

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  • Not sure on your Passat, but if a throttle body doesn't have a idle air control (IAC) valve, air has to get in somewhere to allow it to idle. Commented Oct 7, 2020 at 16:21
  • I don't think I've ever seen a throttle plate that closes completely, but then I've never specifically looked for it.
    – GdD
    Commented Oct 7, 2020 at 16:56

1 Answer 1


Most if not all butterflies on throttle bodies do not close all the way. It stays open to a predetermined gap. The IAC further regulates how much air to increase or decrease as needed to maintain preferred idle.

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