P0221 throttle / pedal position sensor / switch B circuit range / performance

[A4b61.8t]

Hi guys,

Another problem to diagnose................

I had this problem before where the EPC light came on and the esp light too but no other symptoms / issues, so when I scanned the car I got code p0221.

To fix it I removed the accelerator / gas pedal and cleaned up the contacts and put it back together and that seemed to do the trick.........

Until today, probably a year later since the last issue but this time I get the EPC light and the ESP too but this time the car barely started and when it did the rpm's sat really high then went to about 600 and nearly died / stalled.

I managed to get the EPC and ESP light off just by turning the car on and off again but the problem persisted and I scanned the car again to find p0221.

I've just left work and the car started easily but the rpm's are wild, they went really high again like 2k and then to about 600 and the car seems really horrible to drive because it seems like the gas pedal is being permanently engaged and dis engaged at random times?

I will take the accelerator / gas pedal off again tomorrow and clean all contact and also complete a throttle body adaptation, but does anyone else have any other experiences or ideas they would like to add / suggest?

TIA

Liam.

[nicklay]

I would maybe suggest to clean the TBA before readapating it, also, I had this isssue, last week, it appears that I had a leak in my ECU box, The water entered it and frozed and the bottom of the box shorting the relay causing this sort of problem, you should give it a look maybe

[A4b61.8t]

Hi

Thanks for the reply, I have cleaned the TB and the IAT sensor and also the accelerator pedal sensor.

The TB was pretty dirty and it does seem to have helped since I have cleaned it.

But now 1 in 3 times when I start the car it idles really rough and misfires.

The maf will also read really high about 6.0 g/s like the throttle is being permanently pushed but the rpm's do not rise.

Also the boost gauge usually sits at 20 hg but when the idle is rough it will sit at 10 hg.

Any input will be greatly appreciated.

TIA

[seanf86]

sounds like you need a new gas pedal

[A4b61.8t]

sounds like you need a new gas pedal

That's what I thought....... But now I'm pretty sure it's a new TB I need!!:(

[seanf86]

That's what I thought....... But now I'm pretty sure it's a new TB I need!!:(

why do you figure that, theres 2 sensors in the gas pedal for throttle position. The description of the code makes it sound like you need a gas pedal. Do you know anyone with a similar car you could borrow some parts off to troubleshoot?

[A4b61.8t]

why do you figure that, theres 2 sensors in the gas pedal for throttle position. The description of the code makes it sound like you need a gas pedal. Do you know anyone with a similar car you could borrow some parts off to troubleshoot?

Only because when I cleaned the TB the car started and idled pretty much perfect, It was only after a few more start ups my poor idle and misfire condition was back.

It could still be the pedal sensors, I wish there was another car I could swap with locally but unfortunately there's not.

[A4b61.8t]

Hi guys,

A bit of an update.....

The car is still running rough on start up and I have scanned it with vcds and I am getting code 17579 - angle sensor 2 for throttle actuator (G188) implausible signal P1171 - 008 - implausible signal.

I am leaning towards the TB being the problem, but has any body else had any experiences with these codes? As I really don't want to spend any more money on this car.

[petenice00]

Any updates on the source of the pedal position/sensor ‘B’ issues?

[rocket1420]

Only because when I cleaned the TB the car started and idled pretty much perfect, It was only after a few more start ups my poor idle and misfire condition was back.

It could still be the pedal sensors, I wish there was another car I could swap with locally but unfortunately there's not.

You can check what the TPS are reading with VCDS.