EPC, CEL and Traction lights ON - OBDII code - P0221 P - Car goes in Limp mode

[ny2j]

Hi there,

I have been doing a lot of research to troubleshoot the P0221 P code on my 2006 Audi A4 2.0L and gathering all possible options.
Every morning after driving couple of miles the EPC and traction lights are ON. Once i kill the engine and restart the lights go off
and car runs absolutely smooth. These lights are ON intermittently too and sometimes CEL is also ON with P0221 and P0221 P codes.
I am putting together my findings and trying to come up with a logical order of performing repairs to save some bucks while troubleshooting
the issue. I would appreciate any guidance with regards to troubleshooting this issue.

1. Loose connectors/dirty connectors - Tested and found connectors are Ok
2. Battery check - Readings (12.5V, 391 Amps, Low on Amps)
3. Bad gas issues - Switched to Shell V Power last two tanks and got the BG service done 80 miles ago.
4. Brake Light Switch - read that this may cause this error
3. MAF sensor clean/replace - might trigger this performance error
4. Bad ABS Module - had the ABS and flashing brake light ON some 250 miles ago.
5. Replace Throttle Body - If nothing above works
6. ECU malfunction/ Bad ECU - If nothing above works

Please share your thoughts on the list of options above and add/comment if I am missing something here.
Members who have had this error or troubleshooted this in some way please respond or tag someone you know
who has had similar symptoms.

Safe Driving![:)]

[Biged243]

You should do a throttle body realignment there is a dyi for that. Mas could do it and I believe I read somewhere the coils could affect it too, not sure on that though.

[RS4_Fanatic]

Hi ny2j,

I had similar problems on my RS4, although I just had the traction control light on with my EPC light, putting the car into limp mode (car couldn't rev over 3000rpm then). I tried numerous things, from recharging my car battery (I was given this advice from one of the forums), I cleared all errors and disconnected the battery over night, someone thought it might of had a fault memory build up. I also did throttle body alignment and cleaned its connector, but the errors persisted.

But all of this didn't work, I ended up replacing my throttle body and then the errors stayed away. But before doing this, try taking off your throttle body and cleaning it, this might do the trick and will be a much cheaper option.

Hope my advice helped some.

[blackcivic11]

Check the wiring from the throttle body to the ECU first to make sure there are no shorts. Clean the connector for the throttle body. Take it off and clean the throttle body then re-align it. If all else fails change your throttle body.

You most likely need a new throttle body

[eyesolution]

X2 on the throttle body. Try cleaning up the MAF sensor and airbox.

[ny2j]

X2 on the throttle body. Try cleaning up the MAF sensor and airbox.

+1 for TB.


Check the wiring from the throttle body to the ECU first to make sure there are no shorts. Clean the connector for the throttle body. Take it off and clean the throttle body then re-align it. If all else fails change your throttle body.

You most likely need a new throttle body

Exactly.I have squared down to the following plan of action:
1. Change all wires and connectors from ECU to TB.
2. If above option doesn't work, change TB.

[stupdfresh]

I have this same issue after replacing my coil packs.. The car ran fine (besides misfiring - reason i had to replace my coil packs) before changing the coil packs now the car has TC and EPC light. i dont understand why coil pack change would trigger the throttle body to be acting up?? HELP PLEASE![headbang]

[dreamRSallday]

I have this same issue after replacing my coil packs.. The car ran fine (besides misfiring - reason i had to replace my coil packs) before changing the coil packs now the car has TC and EPC light. i dont understand why coil pack change would trigger the throttle body to be acting up?? HELP PLEASE![headbang]

Stupdfresh, did you ever find out anything on your issue? I replaced coil packs also fixing a misfire issue but now I get EPC and TC light as well.

I know this thread is old so I'll keep fingers crossed for a response.

[Mindstorm20]

I had this same problem about a year ago. Replaced the throttle body pigtail and have been good since. Here is the TSB on the problem.
https://drive.google.com/file/d/1-lJc9dD9dL-psYiyZ8ot1RAqJ8fbMS-Z/view

[Ksimsb91]

I have the same issue.
Did ny2j end up swapping throttle body to fix it??
Looking for some feedback. I've had this code on and off for several years. 2 years ago I change the TB and it was gone for awhile. Now it's back again. Limp mode, EPC & TSC lights are on p0221 implausible signal from throttle position sensor.
I can't imagine the TB being junk.. I know it's been a while since I've changed it but still. With all that being said this is the 3rd TB for this car. Guy I purchased it from said they just had one installed at Audi before I purchased it. (5 yrs + ago)
Someone gimme some feedback.

[BorbaBoss]

Same.. I have a B7 Audi A4 Avant, stored it for the winter with a trickle charger. Went for a long drive, went to a restaurant, then left to come home and as I’m turning on my street (20 mins after initial start), epc and TC light came on and the car goes into limp mode.
Got it scanned and the codes were p2122 and p2138.
Wondering if anyone here has any updates on what has worked !?

- - - Updated - - -

Same.. I have a B7 Audi A4 Avant, stored it for the winter with a trickle charger. Went for a long drive, went to a restaurant, then left to come home and as I’m turning on my street (20 mins after initial start), epc and TC light came on and the car goes into limp mode.
Got it scanned and the codes were p2122 and p2138.
Wondering if anyone here has any updates on what has worked !?