EPC and Traction Control Light. Help W/ Codes

[rjd_F30]

Hi Everyone,

New-ish Audi owner and first time poster here. Thanks in advance for your help and time. I have a B7 RS4, and after 5 months of ownership, it's finally thrown it's first warning light. Yesterday afternoon the EPC and Traction Control Lights popped on immediately after mid-corner heavy throttle application with ESP off. Instead of doing what these cars do best and clawing its way out of the corner, it went into limp mode and the EPC and Traction control lights came on. I turned the car off, waited a few minutes, turned it back on, and the lights were gone. Took it for a spirited drive and it drove perfectly. I did pull codes anyway, and here's what came up:

Engine Management:
00289 (P0121) Throttle Position Sensor (G69) Implausible Signal P0121 Not A Plausible Signal - Intermittent

Brake Electronics:
01314 Engine Control Module Read Trouble Codes - Intermittent

Airco:
00819 High Pressure Sensor (G65) Signal Outside Tolerances - Intermittent

I cleared the codes and drove about 25 miles home with no issues. If anyone has any insights or experiences with these codes, I'd very much appreciate your input on what you think might've caused this. My first guess after some research is that the throttle body could be the culprit, but I'd love to hear anyone's input who's more knowledgeable than I am. I plan to just keep driving it and seeing if they pop back up. Also, maybe worth noting: this happened immediately after getting state inspection. I highly doubt this has anything to do with it but it's still a weird coincidence.

Thanks everyone

[blubusdrvr]

Curious what level of ESP you had it in? (Was the traction control off or just the stability?)

[rjd_F30]

I held the button down for about 5 seconds until the traction light was on solid. To my knowledge that was the only setting, besides on. I didn't realize there were two different levels of adjustment.

[CrickiKaze]

quick on-off of the button, this will cause the traction light to flash for the other mode.

[longlivenacars]

was the limp 4k rpm or 7k rpm?

[rjd_F30]

Good question... realized there was very little power around 3k and didn't try to rev it any higher than that so I'm not sure. Luckily I was close enough to work that I was able to basically coast into the parking lot from where it went into limp mode. That's where I turned it off, turned it back on, read, then cleared the codes. I've driven about 150 miles since this happened and still no problems. But still curious of what could've caused it.

[longlivenacars]

Pretty sure it was throttle body, as you also had a TPS code. I incorrectly replaced mine when I had a 7k limp, which is most likely a flap sensor but I still haven't gotten to it. 4k limp I've been told here by experienced members is throttle body usually. The part number in my attached video is a mid-grade aftermarket throttle body option. It has worked fine on my car, but haven't put many miles on recently. An instagram rs4 owner msgd and said they had the 4k limp and changed the TB with an auto zone TB. Had issues with that car not running right. Told him to try the part number from rockauto in my video and he said it fixed the problem. Hasn't messaged back so I assume its been working for him. If you are rich the best option is to get an OE throttle body from Audi if the problem comes back. Lots of info on different GM throttle bodies that can and can't be used out there. This one worked for me so its all I can recommend: https://www.youtube.com/watch?v=5dF_GQv54FM

[rjd_F30]

Great insight and helpful video, thank you! I really wish I knew what sort of limp mode it was in now... anyway, genuine Audi throttle bodies are quite expensive so if I do end up having to replace it, I'll definitely look into the one you used. Very good to know. Still hasn't happened again and the car is still running great so I'm going to let it be for now. But if (probably more like when) it happens again, this will be good stuff to be aware of.

[longlivenacars]

No problem! Please do revive this thread in the case that the problem surfaces again so we all have more cases to help make diagnosing these cars one step easier

[rjd_F30]

Absolutely will do! I'll certainly update in the future if there is an update to give. But, if this is the last post on this thread, future forum readers can assume this issue never came back up for me :)

[TS811]

Hi everyone, I'd like to revive this discussion as I'm facing a similar situation with a 2008 RS4 Avant I recently acquired.

I first got a CEL which I scanned and have the following codes:
- 01314 Engine Control Module, 013 Check DTC Memory
- 18265 Load Signal, P1857 Error Message from ECU

I cleared the codes and scanned again, this time I got:
- 000547 Angle Sensor 2 for Throttle (G188), P0223 - 001 - Signal Too High
- 000289 Throttle Position Sensor (G69), P0121 - 008 - Implausible Signal

Ever since I haven't seen the CEL but I'm having intermittent appearances of the DSC + EPC lights, sometimes accompanied by a limo mode. I recall the limo mode came on at least twice at around 5.5k PRM, kept the car below 3-4k RPM afterwards.

I took it the dealer who says it's likely a throttle body issue. As a first step they replaced what I believe is the throttle body connector/cable, to see if it's that and avoid replacing anything bigger. Unfortunately that hasn't worked so the car's back at the dealer. Now they say the next step is to replace the throttle body, but that the throttle body is part of the intake manifold so the whole intake manifold needs to be replaced.

Can anyone confirm this? Any other thoughts based on the error codes? The dealer happens to be a family friend so I tend to trust them, but want to double-check before signing off such a major repair bill.

Thanks in advance!

[CrickiKaze]

The TB can be replaced with out replacing the manifold, 1 nut and stud bolt with 3 torx bolts.

[TS811]

Thanks, I spoke to the dealer earlier and they also came to that conclusion after a bit more research. Good news as it's less than half the cost!

Unless anyone has any other thoughts based on the error codes (could it be ECU related, I hear things like water damage to the ECU can cause these errors?) I'll go ahead with the repair order.

Thanks!

[longlivenacars]

If you decide to do it yourself, you can follow steps in my video from a while ago. As stated by others, far earlier step than manifold removal:

https://www.youtube.com/watch?v=F7riaCy10NA&t=62s

Check the video in a post I have above of a tb that has worked for some people that have saved money, but with an avant level of purchase money of today, maybe you are going the stock part #route which I understand

[JDMV8]

Hey, I just had the 4k RPM limp mode and G69 and G188 error codes with ECM codes. I couldn't do a throttle body adaptation via VAGCOM, so I swapped in a corvette throttle body (same exact part as the OEM pierburg, just with a different stamp) and the car drives like a dream now, no codes. Switching the throttle body out took about 25min with a few simple tools.

[rjd_F30]

I read about certain GM throttle bodies being compatible... can you share a GM part number for the TB you used? I'm taking my car on a 1500 mile road trip next week, and it would be nice to know which GM part I can use, if even only temporarily, while I'm on the road (god forbid this code pops again while I'm in the middle of nowhere). I assume it'll be much easier to find at a run-of-the-mill auto parts store than the Audi part.

[longlivenacars]

Please do post the part #

Alright so amongst a number of Canadian rs4 owners that have run into the throttle body issues over the years, there was great debate until I settled on that aftermarket part. There was talk about the GM parts offered that can be used being ever so slightly different in terms of build (materials/electrical/something, I can't remember exactly, was a while ago, I maybe remember the word brass being used as one of the things to look out for making certain GM TB's not work/ or work lol).

In short I never got that correct GM purchased part info, but one Canadian owner had success with the aftermarket part in my video, before I used it. As of today I know of four people that have been good with that one as a replacement, but I have always thought something straight from GM MIGHT be a better long term alternative in terms of longevity

[JDMV8]

No problem, here is the new superseded part #: 19420034. Buy straight from a GM dealer.

[CrickiKaze]

The manufacture is the same for the GM unit as for our unit I forget where in Europe the manufacture is but at a certain point something changed with the GM unit and the only indication is the brass color throttle plate and the LS guys are aware of it. I can't remember which LS motor uses it but I know it's in the Pontiac GTO and I believe it has an LS2 or LS3 so any Corvette will have it as well with that motor.

I was on a hunt to find an aftermarket unit that works but was derailed and haven't been looking since.

[rjd_F30]

Thanks for that PN, good to know. Does it matter for us whether it's the part with or without the brass throttle plate?

[JDMV8]

The part should be without the brass colored butterfly valve. Should look exactly like OEM.

[rjd_F30]

Great info, much appreciated!

[TS811]

Picked up the car from the Audi shop on Saturday after replacing the TB with an original part. So far so good.. hoping it stays that way!

[Vzsgzsas1z29]

It's a bummer when those warning lights pop up, but you're handling it like a pro. Based on the codes you got, it does seem like the throttle position sensor could be the culprit, but I'm no expert. You might want to check out the Audi a4 esp light on guide, for some helpful tips from experienced Audi owners. They've probably been through similar situations and could offer valuable insights. Keep an eye on it, and if the lights come back, it might be a good idea to have a mechanic take a closer look. Anyway, good luck, and I hope your RS4 stays trouble-free for many more spirited drives.