gg117

I have a 2001 S8 with 56K miles. The ESP and ABS lights are on the dash so I took it to the dealer. They said two ABS trouble codes are coming up and estimated 4 hours to diagnose the problem because the trouble codes have 12 pages of diagnosis work they have to go through. So it will cost $400 to tell me what's wrong. From there we will have additional labor and parts. They are guessing it's the ABS control unit. Does anyone have any insight regarding this? How much is an ABS control unit?

Thanks

TimD

Its most likely a wheel sensor. Get vag-com and do it yourself.

TerminA8r

<ul><li><a href="https://forums.audiworld.com/a8/msgs/58269.phtml">Click this thread for pics and instructions</a></li></ul>

JimR

I guarantee that would be madly expensive.

They haven't diagnosed it, but they *think* it's an ABS controller!? B.S.

Not sure I'd return there.

PaulW

He couldn't get his ABS to kick in....after doing tons of troubleshooting, it enged up being brake dust in the ABS teeth/sensor. Cleaned it and it went away.

Post the codes and we'll point you in the correct direction.

clong

I just replaced the ABS controller on my 97 A8 2 weeks ago.

The stealer quote me $1400 for the part and $180 for labor.

I found one in a junkyard for $125 and a Mercedes shop installed it for $140.

skiwi

i'd suggest that 12 pages of diagnosis is not bs, but most of it would not require anything other than vag-com and some time....

gg117

01464
Brake pressure/lateral acceleration sender
voltage supply

01423
Lateral acceleration sensor-G200
electrical fault in circuit

gg117

The dealer said they narrowed the problem down to a bad lateral acceleration sensor. Cost for part $400, plus $400 in labor. They won't know for sure that this solves the problem until they replace the unit tomorrow though.

Here are the codes they first pulled when they started trouble shooting the problem

01464
Brake pressure/lateral acceleration sender
voltage supply

01423
Lateral acceleration sensor-G200
electrical fault in circuit

Thanks for your advice...

skiwi

either:

1) a voltage supply problem between the sender in the esp pump (location front left infront of the wheel in the engine bay - its the cylinder below the abs relay). check terminal 3 to the abs control module (j104) terminal 69 for a short to ground. the control module is in the instrument cluster - you will need to remove this - it can be done without removing the wheel.

2) insufficient voltage to the transverse acceleration sensor g200 - this is under the drivers seat. check terminal 3 of g200 to j104 terminal 75 for a short.

3) a sensor malfunction. if voltage supply is ok, then the procedure is to swap out each sensor (g200, g201) for a known good erasing dtc's each time to find the issue.

4) if this doesn't sort the issue, then you will need to replace j104.

hopefully you will find a wiring fault and not have to spend the $'s