ronnjr04

Hey gang can anyone tell me if you can rebuild the ABS module on an 2004 A8L & if so is it cost effective or just go ahead and buy a brand new one? Thanks

Panelhead

You need to check the cost of a new one. They are expensive and should require coding to the car.
Mine has started to act up. Temperature related. Cold mornings it is fine for 5 miles. Then get ABS light, parking brake failure, and chimes on stops. Hot weather it malfunctions on start up.
Just sent the ATE ABS controller and pump from the wife’s 335i to Module Masters. Being recoded today. Lost code somehow.
Once working I plan on pulling the one from the A8 to see if I can fix. If not off to Moscow ID. Not as many options for recoding for Audi as BMW here. Bemer’s are less than 150.00 from independents.

The 3 series E90 BMW ABS is real common failure

ronnjr04

Thanks i already checked the part cost ]on Audiusa.com and it's a whooping $1866.48. Most likely I'll have to invest into that if I want to get the car back on the road. And part 2 to your answer again with the BMW 335i. My daughter has an 07 and now I'll be looking forward to most likely replacing that ABS module. But keeping my fingers crossed that i won't need to anytime soon.

ScottCNelson

https://modulemaster.com/rebuilds/sh.../abs-bosch-57/

ABS Repair | ABS Constantly Running | My Auto Solutions Buford Georgia

Panelhead

Just picked up the wife’s 2007 335i tonight after recoding with the ModuleMaster rebuild. Works perfect. Had another issue that may have caused the coding problem. Indy said it had to be fixed to recode system.
MM rebuild was 290.00 with shipping. Might not have required a recode if there was no issue with the brake wear sensors. Saw this with iCarsoft scanner but thought it was ABS controller related.
I am pulling the ABS from the A8. May send to Module Master. May look for broken solder joints on the power input pins. Some have reflowed these and fixed the controller on BMW. Mine is definitely heat related. Suspect electronics, not bad solder joints, too consistent failure after five minutes of driving.
If you buy the controller, the dealer may charge up to 500.00 to code to the car. An Indy should do for a third of that.
Can I recode with VAGCOM?

storka

yes can do it yourself,
Read up on it first

Panelhead

Thanks, will if it requires recoding.

aTOMic

The wires are just millimeters apart, potted in some sort of goo for corrosion resistance, and they're thin as a hair. Unless you're a soldering ninja, you will NEVER get them resoldered.

audijim113

You can have it rebuilt for about $150 (not sure, price may have gone up a couple bucks) Getting it off is a bit of a trick. I wrote up the whole procedure and have sent it via email to a couple guys. I'm not sure if I can cut and paste a word document here. It also has pictures.

August, 2017

The Bosch ABS module failure is common on many Audi models and years, even on some American iron. I drive an 06 now and perhaps will experience it soon. Last year, driving an 05, I posted the following info and "how-to" on this issue. I just went over it to clean up typos and clarify a couple things.

P0501 indicates loss of speed signal from front, left wheel speed sensor. The signal is used for a number of functions, including Elect Park brake because park module needs to "know" speed to inhibit applying brake over 5MPH. If module doesn't see the signal, it thinks something’s wrong and throws code plus obnoxious beep. In addition to speedometer not working, variable speed power steering is screwy, calculations for trip computer such as MPG, won't work nor auto door lock at 5MPH. It also might impact tranny shift. You may or may not get all of this. The parking brake fail and obnoxious beep, is the worst.

Here is my explanation and "How-to".

A thread I posted way back labeled “ESP” and other comments described is exactly what I went through for over a year. It started with Parking Brake warning and progressed to ABS, Brake and ESP intermittently. I replaced speed sensor, brake light switch and cleaned contacts on the ABS connector several times. Also peeled back the tape on the bundle of wires from the speed sensor to ABS and into firewall looking for frayed, deteriorated wires.

The "gritty" feeling operating the latch one guy described is road dirt, sand and crap in the plastic latch release for the abs module connector. It can make the latch hard to operate and if forced, will cause the latch to break. To make is easier to operate the latch, I used air pressure to blow it off and sprayed cleaner on it. As with any “stuck” item, slowly move the latch back and forth and continue to spray or blow with air. In case there were some dirty pins on the connector, I cleaned the whole connector, sprayed contacts with electrical cleaner several times. This had no affect other than to make the latch smoother.

The ABS module can be seen on the driver’s side under the power steering and coolant reservoirs. A bundle of wires wrapped with black tape ends in a big connector / latch that attaches to the module.

I "lived" with the warning lights, etc for a year, trying to chase down the gremlin. The most annoying thing was the parking brake warning and the beeeeep which went off after stopping for a light and reaching about 10 MPH again. Not everyone will have the parking break warning, (at least not at first).

My short term solution to stop the noise was pulling the two 30 amp fuses for the brake. (located in trunk in battery compartment, bottom two blue-green fuses on panel forward of the bracket/lift motor assembly). Without fuses the BRAKE light on dash blinks. It’s visually annoying but at least it didn't beep. I was able to drive (carefully) without ABS function, ESP, speedo and of course, elect park brake. Also, the power steering was too sensitive at hiway speed.

My problem went from intermittent to predictable. It worked fine on cold start up first thing in the morning, but after a few miles warm up it went into “**** me off” mode. When it failed, the speedometer stopped working, accompanied by the ESP and ABS light. Obviously, on ice, etc, the ABS did not work and variable speed power steering didn't work right at highway speeds, (it was too sensitive). One very temporary solution which allowed me to drive longer before it failed, was a piece of insulation between the module and the exhaust manifold. Heat from the exhaust is apparently the killer to some poor factory connectors inside the module. Mother nature allowed a few more miles of driving when the temps got down below 10 degrees.

Note, in the year I messed with it, I always drove it. I just lived without ABS, ESP, etc. Back the day, no one ever heard of ABS, ESP, etc. As a teenager, the only ESP (for extra sensory perception) was my girlfriend who instinctively knew I was horny and didn’t let me go as far as I wanted. My 56 Chevy or all the other cars I had for many years before graduating to Audi’s didn’t have any of these safety gizmos yet I survived.

The problem was finally fixed by removing the ABS module off and sending it to “Cheap ABS Repair” for $150 bucks or so with shipping. Some people will tell you the modulator needs to be removed by disconnecting brake lines. My answer: THE MODULE CAN BE TAKEN OFF WITHOUT REMOVING THE ABS MODULATOR PUMP BRAKE LINES OR HAVING TO BLEED LINES AFTERWARDS. I anguished over how to remove it. It is damn tight in there especially for someone like me with big paws. There are a couple videos on the internet but none really apply to the D3 A8. I made a video but it's in multiple parts and choppy. (I'm not a video guy). Also, I can't figure out how to put it in a youtube and post it here.

It is not easy. If you have big hands, physically challenged, etc, you may be tempted to give up and pay big bucks for someone else to remove it. For the feint of heart, I am 74 yrs old. (72 when I did my 05). I also weighed 325lbs. As for flexibility, I have very little. Even having lost 65lbs, I don’t bend worth a dam. My hands (bear paws is a better description) are really big.
Here is my best “How to” description:

1. Remove the coolant reservoir, (suck it out first), disconnect hoses and elect connector underneath.

2. Disconnect the power steering reservoir from the bracket and move out of the way as far as hoses allow.

3 Release the connector latch on the ABS module and pull the connector up. (If you haven't done it previously, blow the grit away with a blast of air). Lift latch gently, maybe up/down incrementally. Yes, it can break.

4. Move the connector and wire bundle out of the way. Don’t manhandle it.

5. You can now see the top of the modulator pump. This is the thing with brake lines coming out of top. One either side (front/rear) are rubber mounts which are part of the “cage” which holds it.

6. Thin metal "clips" hold pump in the mounts. Clips are hard to describe. They are thin metal over the rubber. Pull them away and up. The rubber covered mounts stick out fore and aft. (that’s nautical talk for front and back). They are round things with a rubber around them. With the clips removed, it allows the modulator to move. The whole thing can be pulled up using the brake lines. Brake lines are flexible to an extent. Don’t use a giant pry bar or go gorilla on brake lines. I’m editing this now with a picture of the mounts with the “clip” things. Someone had told me about them but I didn’t know how they came off. I bent the hell out of them, prying, but finally figured it out how they came off. You are only taking the thin metal off. It the part shaped like an upside down “U” with a perimeter around it.

-------------------There was a picture here but it didn't copy from Word. I'll dig it up and attach later--------------

The holes in the end are nothing just marks or molding marks in the rubber. There is a lip at the top. Arrows point to the metal If you fool with it, it should come off. It holds the rubber boinky part in the “cage”. If memory serves, I recall pulling the tab at the bottom away from the cage and it will move up and come off.

7. Once free, pull the modulator up to the extent the brake lines will allow which is only an inch or so. A coolant hose (fabric covered) is in the way and needs to be pulled up out of the way. A separate rubber thing is on the bottom of the pump fits into a hole in the cage. It will lift up but weight of the pump will let it go back in when you aren’t pulling up on the brake lines.

8. Hint: get a piece of wood (I used a flat carpenter's pencil) and put it under the pump where a rubber mount fits into the bottom shock mount.

9. The idea is to keep the pump in the lifted position. (yeah, as you monkey with it, trying to get in position to remove the module screws, it will fall back down and you'll have to reposition the wood or whatever you use to hold it up several times.)

10. With the pump elevated, you can get to the screws that hold the ABS module to the pump. I think they are t-20

11. Have a magnet extension handy as the screws tend to drop

12. Obviously the ones on top and towards front of the car are easier. The ones in the back, especially bottoms are a PITA.

13. If I didn't tell you this, make sure your car is cool before starting. To get screws off, you don't want the exhaust manifold hot as your hand won’t like it.

15. You'll need a variety of 1/4" ratchet, short extenders and various length torx bits. You will drop them many times! The depth of a rachet can be a problem. I’ve had this tool (link) for 50+ yrs and it came in handy. Looking it up, I see it still exists. (link). I also use this to get the bottom screw off the MAF where it connects to the air box to reach the filter housing when I change my oil.


16. Once you get all 6 screws out, the module can be separated. Be sure to pull it squarely back from the pump to separate the little solenoids shafts. At 14.20 on this video, it shows what I mean about the module and solenoid shafts. This video is just to show you the solenoid “things”. It can be found on the Cheap ABS site, titled, “remove from A6 or A8” but it is an A6 and not the same as an A8. However, it does show the module and how it separates and the solenoids rods. I was going to create a nice video and give it to Matt (owner of Cheap ABS), but I’m not technical enough and gave up. Again, this video (at 14:20) is only to show the module coming off the solenoids.


17. With the module in your hand, wrap it in bubble packing. It is now ready to ship to Cheap ABS Repair

Before you started all of the above, complete the form on CHEAP ABS Module Repair for Audi and follow the instructions. You have to pay first, then ship the module to them. Read all the stuff. It will take 5-6 days to repair so consider transit time for which day you mail

What CheapABS does is fix the internal contacts on the circuit which used a flawed factory process and are subject to fail with heat (proximity to exhaust) and vibration.

As they say, "installation" is reverse of above steps.

Can you drive your car with the module off? There are conflicting opinions. The answer is, "depends". You are not going to have any of the functions that travel through the module, but before I took the module off, I was able to drive for a year off and on without these functions with no sweat.

Also, I'm not positive on this but the air suspension might be affected. I did notice when it failed, the "LIFT" mode didn't work on the air ride, but I don’t know if that affected the actual operation. My plan was to drive the car with the module pulled out. I did this a few years ago on a 98 A8 but it didn’t have all the functions of the D3.

I was going this on my D3 (wrap modulator where solenoid rods stuck out) with plastic to keep moisture and dirt out. In the end, I left it in the garage since I had a "spare" car and my wife didn't make too much noise when I left her without a car. (yeah, it helps we're both retired). My wife’s car is a 98 A8. The module is much easier to remove. Years ago, I sent her module to Cheap ABS. During the week or so it was in transit, I drove her car with the unit wrapped in plastic.

audijim113

here is the picture of the bracket holding abs modulator in "cage"

Note, remember the video in my previous post is NOT of ABS remove in an A8. It is for an A6 and is only to show the modulator solenoid to module visual.