Whats up Audiworld? So, the other day I start up my car, and notice the ABS & ESP lights are on. In addition, the car feels Very weak in first & second (auto tranny) and will rev way too high before shifting.

I copied the codes thrown below, but can't seem to draw a conclusion as to the source of the issue... maybe you guys can?

Thanks again so much...

Friday,10,July,2009,21:03:00:32608
VCDS Version: Release 805.4
Data version: 20090602



--------------------------------------------------------------------------------
--------------------------------------------------------------------------------


Chassis Type: 4B - Audi A6 C5
Scan: 01 02 03 06 08 15 16 17 18 34 35 36 37 45 55 56 57 65 67 75
76 77

VIN: WAUML64B34N053529
-------------------------------------------------------------------------------
Address 01: Engine Labels: None
Part No: 4D0 907 560 CT
Component: 4.2L V8/5V G 0010
Coding: 07752
Shop #: WSC 02334
WAUML64B34N053529 AUZ7Z0C2479353

3 Faults Found:
16955 - Brake Switch (F): Implausible Signal
P0571 - 35-00 - -
16497 - Intake Air Temp. Sensor (G42): Signal too High
P0113 - 35-10 - - - Intermittent
16486 - Mass Air Flow Sensor (G70): Signal too Low
P0102 - 35-10 - - - Intermittent
Readiness: 0000 0000

-------------------------------------------------------------------------------
Address 02: Auto Trans Labels: 01L-927-156.lbl
Part No: 4B0 927 156 FG
Component: AG5 01L 4.2l5V USA 1014
Coding: 01002
Shop #: WSC 02334

2 Faults Found:
17087 - Brake Switch (F): Electrical Malfunction
P0703 - 35-00 - -
18265 - Load Signal: Error Message from ECU
P1857 - 35-10 - - - Intermittent

-------------------------------------------------------------------------------
Address 03: ABS Brakes Labels: 4B0-614-517.lbl
Part No: 4B0 614 517 H
Component: ABS/ESP allrad 3428
Coding: 06397
Shop #: WSC 02334

2 Faults Found:
00526 - Brake Light Switch-F
27-10 - Implausible Signal - Intermittent
18265 - Load Signal: Error Message from ECU
P1857 - 35-10 - - - Intermittent





-------------------------------------------------------------------------------
Address 35: Centr. Locks Labels: 4B0-962-258.lbl
Part No: 4B0 962 258 M
Component: Central Lock/Alarm D38
Coding: 14925
Shop #: WSC 08353

2 Faults Found:
01368 - Alarm triggered by Luggage Compartment Switch
35-00 - -
01561 - Left Rear Door
59-00 - Can't Unlock





End ---------------------------------------------------------------------

 

Clear codes, drive, see what comes back.

 

Won't be able to clear again until tonight or morrow (friend's VAG), but I know we did clear and re-ran just the engine, and those 3 codes came back. I'll clear again ASAP though

 

They came back... any thoughts guys? I'm thinking MAF, but want to confirm before I go crazy

 

I found this posting on a search to self diagnose my car. The problems listed with the traction control and ABS lights are identical to what I currently have. I also have sluggish acceleration in the low gears. The only difference is I have a 04 2.7t s-line. I am looking to see what the outcome was for CT or if anyone knows what the issue is with this.

Based on my searches I have concluded that either my ABS module is shot and I need to spend anywhere from $200-$1000 to fix, or perhaps my brake light switch is broke and for $25 I can do it myself.

So my question is, do you think with the symptoms my car shows, do you think it could be the brake light switch? If so, is there a write up on how to change it? I do not know the inside workings of my car that well, but people make it sound like an easy DIY job. Sorry for not having codes yet, I am working on meeting a member locally who has a vac com so I can get those.

Thanks,

 

My 2004 A6 4.2 has had the same problem intermittently for months, but this week it seems to have settled in to stay. Acceleration from a stop is painfully slow. Note: I've recently discovered that if I immediately take my foot off the gas and reapply pressure, the hesitation is instantly gone and acceleration returns as normal until the next stop.

I'm curious if anyone has resolved the issue. I'm pulling codes tonight to see if anything shows up. My guess is ABS sensor.

 

Follow up: I replaced the faulty brake pedal switch ($16 at the dealer) and the many problems resolved immediately. Note: follow instructions for mounting switch. depress the pedal, insert, release pedal, twist switch to lock in place. This sets the position of the switch. If you fail to do this, you will not have a successful installation. In fact your transmission may stay locked when brake is applied at park.

All transmission hesitancy has gone away, performance is fantastic again and codes have cleaned up.

 

Today these 2 lights won't go away and found no brake lights totally. Plus the sluggish to pick up the speed from stop.
Rushed to Audi dealer to grab the switch $12.55 (incl tax)and search online re DIY replacement and found VW Passat was in recall of this so dealer can fix it for free. How come Audi was not recalled?

The new repalcement is in a little different shape than the original one. To describe it should be "meaty"

You can find the replacement instructions on the Passat
http://ww2.justanswer.com/uploads/de...all_Notice.pdf

Except my 2002 under dash panel are secured by 5 bolts. 2 at bottom, 3 in top part. You can find the info here (68-7).

Another small difference is A6's sitting position is 4 pin connector is at lower portion, not the upper portion as the passat one idicates.

 

thanks for the great info. My wife has had my car (03 A6 4.2) for the last several months and she called the other night to report the same symptoms. I sent her to the local dealer and suggested they check the brake light switch. That was it and she was back on the road in no time, and the dealer's price to fix it was reasonable considering I was a 14 hr drive away. I don't know what the cost may have been had we not told them our suspicions going in the door. Knowledge is power.

 

I know this is an old thread, I'm hoping someone is still watching. I got the new brake switch sensor, installed it like the instructions said, and the light came back, no change. All the same initial problems - hesitation, high revving after braking around a right (tight) corner followed by acceleration, etc.

I followed the instructions exact that came with the switch - namely, to NOT press the pedal while installing, but to carefully put it in place without pressing or pulling the brake pedal. Are the instructions wrong? I was afraid to deviate for fear of making things worse by locking things up.

Any insight is greatly appreciated!