fdk110

I have an ML320 (year 2000), and the three lights ABS ETS and BAS are lit. The dealer has diagnosed it as having a bad ABS control unit and the associated relay. They gave me the part number for the control unit as:

163-545-58-32.

They also mentioned an estimate of about $1400 for the parts and labor.

I found a couple of people on ebay that can repair the unit. My questions are as follows:

1. Has anyone used any such service for rebuilding/repairing ABS control units?

2. Where can I buy second ABS control unit?

Thanks

Don

bmwmenot

You can get a new one for around 700 to 800..a search on google gets a few hits.. Rebuild is usually a hit or miss.. If you feel adventurous and not have much to lose, crack open the broken one and check it out..could be bad solder joints..

fdk110

Got a used ABS control module exactly mactching the part number from the dealer. No Joy. I thought maybe the used part was bad. Got another one. No Joy.

But now, after the second unit, the scans only show C1401, indicating a bad ABS pump. New ones go for about $1800 plus labor. I also found this:

http://www.mercedesshop.com/shopforu...d.php?t=163247

Apparently, the circuit board on the ABS pump assembley is prone to cold solder joints. I guess that is what BMWMENOT meant when he suggested to break open the cover.

I will follow this this and let everyone know the outcome.

fdk110

I finally resolved the issue and am posting this to help others avoid what I went through. Some of what happened here appears to be due to sheer bad luck. But still I would hate for anyone else to fall for the same thing.

I learned a lot from the following post but I was not clear on some of the points and I have tried to further clarify these points. Hopefully I am adding some value here. There are points that he goes through that I am not covering and I definitely recommend reading his post.

http://www.peachparts.com/shopforum/...d.php?t=163247

To recap, I had the three lights come up on the dash. The most common cause of this a bad break light switch. I had that changed and it did not help. Next I changed the two relays in the fuse box (K25 and I believe K6). No joy.

I had the dealer scan the car. They determined a bad ABS/ETS computer with the part number:

163-545-58-32. It is under the fuse box.

The part goes for $900 from the dealer and they wanted $500 for installation. I got a used one and installed it myself. No Joy. I thought maybe the part was bad. I exchanged it for a second one. Still no joy. Took about an hour, BTW.

I went to another dealer for a second scan. They determined I had a bad ABS pump. $1800 for parts and $700 for labor. It turned out that the real problem was with the pump and the part mentioned by the first dealer was not the problem. Most likely, the guy fat fingered the keyboard and instead of choosing ABS pump, chose ABS/ETS computer.

The ABS pump has two parts. The mechanical part and a circuit board with some selonoids. The latter is what usually goes bad. You can easily take out the circuit board and send it out for repair.

To do this, you need to take out the driver side headlight. There is one screw on the upper side of the headlamp, which is visible. There are also two nuts on the lower edge but they are not visible. You have to first take off a piece of plastic (same color as the car) which is right under the headlight. This is done by pressing on two tabs at the end of this piece. Once this is done, release the plastic piece and set it aside. The two nuts become visible and can easily be taken off. The headlamp will then come off.

To the left, and right next to the windshield washer reservoir, you will notice a black plastic box which is attached to a metal square block with lines coming out of the block. The black box is the circuitry and the metal square is the actual pump. Four torx screws attach the black box to the pump. You will need torx sockets.

Three of the screws come off easily but one of them does not have enough room for the socket and the driver. I used an adjustable pair of pliers to grab the torx socket and take off the torx screw. Once you do this, the plastic piece comes off. No oil is released either.

Next you need to take off the connector. This is tricky. The connecter has a cover that is also a ramping device. I managed to pull this half way and then had to use the adjustable pliers to pull it off all the way. Once the ramping device/cover comes off, it also disconnects the connector and you will have the circuit in your hands.
Now the fun starts. Either send the unit away for repair or if you are handy with a soldering iron and an ohm meter or a continuity tester you can attempt a fix.

If you want to send it away, search ebay and there are some standing offers for this . This is the one that I found but I did not use them and don’t know how good they are. Check out their feedback and decide for yourself.

http://myworld.ebay.com/ebaymotors/bba-remaninc/

In a nutshell, the post from the Mercedesshop.com (above) notes that some of the pins on this circuit are badly soldered and over time could become loose. You can easily check the connection with an ohm meter and if this is the case you can re-solder the bad joint. Note that the back of the circuit is sealed with silicone but you can easily take this off with a knife taking care that you don't scratch the printed circuit.

When you get the unit out, you will note a black stub protruding from the back with two pieces of metal at its tip. These two carry the power to the motor that is part of the ABS pump unit. These two are connected to the bottom two pins on the connector. Check the connection between the two power pins and the two pieces of metal at the end of the black stub. If there is high resistance or if there is no connection, you need to re-solder the joints.

Apparently it is possible that other things could be wrong with the circuit. If that is the case, you may want to send it away for repair.

I also read in another post that someone had the same symptoms and went through all these steps and even sent his unit out for repair and still could not fix the problem. He finally traced the issue to a chafed wire that was part of the bundle of wires that goes to the ABS unit. At the end he solved the problem with soldering the wire. As such, it may be advisable to take off the driver side headlight and make sure that the wires are OK, before attempting any of the above.

I also want to mention that while going through this I learned of a great site for used parts. The site allows you to search the inventory of many dealers and allows you to sort the results by distance, grade of the parts, etc. I have no connection to them and am mentioning them as an FYI only.

www.car-part.com

Hope this helps.

hampshirewoody

Can you drive the car while the board is off for repair ??? I am driving my 500 with all lights on and dealer says its the pump, sounds like is worth having a a go at fixing the soldering first

opmommy

Hi, I see this list is old but I'm posting in case this comes up for others.
I had the same problem as the OP, and three lights which I believe are for ETS,BAS,ABS turned on intermittently on my dash. When they were on, it sounded like a pump or belt kept running even when the car was off.
I took to a repair guy and got the responses already posted, bad ABS pump was running and it killed my battery a couple times. Replacement part is +$2k.
My guy said that his aunt was having the same problem with the same part in a caddie or similar and HE as a repair guy, had opted to disconnect it instead of replacing. So he pulled the relay (or whatever it is called) and the car works fine, i just don't have ABS or super traction control, so I have to be more careful in ice and snow and drive like with cars that have neither.

I'm really relieved because the car runs well otherwise, it's a 2001 so really not worth another $2k for features I can live without. I'll probably trade it in for something else next year.
This video link shows which plug to pull in the car's "fuse box" http://youtu.be/LhFMhAoUlJg

Good luck!

DTaggert

I have a 2000 ML 320 and I recently had the BAS Control Module replaced b/c of this same problem, BAS, ABS, ETS lights coming on. It was a horrifically expensive repair, $3400. About a week after the repair, the lights came back on. I returned to Mercedes and they couldn't figure it out and, of course, the codes wouldn't come on for them. Several weeks later it started to happen more frequently. I took it to a friend who is a Lexus mechanic with a lot of German car experience as well. I left it with him and the pump ran continuously for at least 6 hours. He took the temp with an infrared thermometer and it was running at 302 degrees hours after I stopped driving. I took it back to Mercedes today. They are saying that the relay or release switch (not sure what they said) is sticking so they are replacing the release switch. My concern is this - if this fixes the issue, my friend said that the entire module should be replaced b/c it ran hot for so long. Thoughts? I have already spent a fortune on this issue and I can't say that I have a lot of faith in the dealership right now.

DTaggert

I have a 2000 ML 320 and I recently had the BAS Control Module replaced b/c of this same problem, BAS, ABS, ETS lights coming on. It was a horrifically expensive repair, $3400. (Unfortunately I did have the time to research it at the time and I just trusted the dealership, silly me). At any rate, about a week after the repair, the lights came back on. I returned to Mercedes and they couldn't figure it out and, of course, the codes wouldn't come on for them. Several weeks later it started to happen more frequently. I took it to a friend who is a Lexus mechanic with a lot of German car experience as well. I left it with him and the pump ran continuously for at least 6 hours. He took the temp with an infrared thermometer and it was running at 302 degrees hours after I stopped driving. I took it back to Mercedes today. They are saying that the relay or release switch (not sure what they said) is sticking so they are replacing the release switch. My concern is this - if this fixes the issue, my friend said that the entire module should be replaced b/c it ran hot for so long. Thoughts? I have already spent a fortune on this issue and I can't say that I have a lot of faith in the dealership right now.

Maj. Dundee

The relay was the problem all along. Never believe what M/B tells you.

As a matter of fact there is no release switch. None whatsoever. The relay is fused together. Known issue. The computer is not damaged, if anything it is the ABS pump.

If they want to charge you, decline and pull the truck out and replace the relay by yourself.

DTaggert

Thanks Maj. Dundee. How could I prove that it was the relay? When I asked about it, MB says it would have thrown a different fault code showing a connection issue. Even if that's not the case, how could I prove that they replaced the control module unit unnecessarily. They have their codes to fall back on. They are saying the relay failed later b/c it was two months between the time they replaced the module and now. I told him that replacing the module never fixed the issue b/c the BAS, ESP, ABS lights were still coming on intermittently. I had brought it back once over the past two months, but was sent away b/c they couldn't find anything. Then it was the holidays and it was so intermittent that I only decided to deal with it once it became a daily problem. I think I'm stuck with their shoddy work and the bill unless you have any ideas? Did I also mention that when I returned to the dealership this time (two months after the replacement of the control module) I discovered that I had a spongey brake pedal and low brake fluid. They had flushed the system when they replaced the control module so clearly they caused and air bubble in the line. They have cleared the air bubble and filled the fluid, but discovered no leak. What would be your next step?

NYCFIXMYPC.COM

I have the ETS/BAS/ABS Lights as well. ML430 with a little over 100,000 miles. after researching a lil on the internet I will start with the abs relay and or wiring. it seems to be fixing everybody's issue for cheap. I'll let you guys know what happens.

NYCFIXMYPC.COM

Do you have the number to your mechanic?
I am in NY with the same ETS,BAS,ABS light issue. (ML430)

NYCFIXMYPC.COM

so i had the abs control unit and the yaw sensor replaced. ($1700 later) bye bye ets/bas.abs lights

xray84

just giving my 10 cents here read these other posts and well i had all three abs related lights on ,on my dash....so i just went out and crawled underneath my 320 where the pump and motor are located behind the drivers headlight and just wiggled the 15 pin connector without even removing it just yet and sweet it worked.....and another thing to removing if you do so everything on mercedes are known to be torx bits internal and external which are metric which are not cheap as regular sockets and bits.....you can go to any auto parts store and by them mostly sold individualy.....also the cover over the 15 pin connector you wont break it off if you lay down underneath like i said before and just push the cover up it slides in place .....

cobracop

bought a 2000 w/ all the above lights on. would changing the factory 16"wheels to 18" also cause this? couldn't get any codes for them on the OBDII.

Maj. Dundee

Once those lights are on there will be codes set. The correct scanner is not being used.

cobracop

it was the K25 relay, THAAAANK GOD!! and thank you maj dundee for your previous post in this thread with the pic. replaced it with the power window relay and what do you know no more lights. check this out yourself folks and save a bunch of cheddar!!

RNotamechanic

My 1999 ML 320 has had a humming sound about when it shifts into second gear, and then the three lights on the dash appear for the rest of the drive. MB replaced the stop lamp switch, which worked to shut off these lights only momentarily...then I the got passenger tires stuck in two feet of snow and after digging out and driving to the next destination the humming was louder and something wouldn't stop running when the car was ostensibly shut off. Next, a terrible grinding noise occurred when I tried to restart it, so it was towed to MB and 4WD mode electric motor was replaced (code 163-540-09-88).

So now the humming is back and louder, and the lights are still on...husband disconnects the battery to shut off whatever is still running after I turn the car off. MB said the washer fluid drained on the ABS pump and it needs to be replaced for +$2700...kind of steep for a $4000 car...but I love it and took it home and after reading this wonderful series of posts, took out K25 which I think is the "relay"? Then drove around the block, all three lights came back on but the car did stop humming when I shut it off...however, my husband added windshield washer fluid and now there's a leak of some sort on the passenger side of the car which doesn't seem right since the reservoir is on the driver's side...? Does the part I removed cause the 4WD electric motor to keep running? Should I replace K25 or go for the ABS pump fix? It seems like we need to replace the washer fluid reservoir, but why is it leaking on the wrong side? Any thoughts are welcome!

Maj. Dundee

What is happening is relay K25 is stuck in the closed position and the ABS pump is running continuously. Switch relay K25 with K21 (blower motor) and see if the humming stops.

If the humming stops keep the good relay in K25 as it is more important than having a blower motor (no heat) until you get a new relay. If the humming does not stop then you must inspect the wiring at the ABS for breakage/corrosion.

You must stop filling the washer bottle until you get a new one as it will have an affect on the wiring of the ABS pump, if not already.

Post back with results.

RNotamechanic

Maj. Dundee, thank you so much! The K21 worked perfectly - the three lights went out and the pump stopped when I turned off the car! I'm not sure about a leak in the windshield washer reservoir - there is evidence of blue stuff dried on parts, but nothing wet...I'm thinking maybe a result of a sloppy fill job...? The K25 part is listed online for about $20 - dealership has it for $37 - anyway, a great deal compared to the $2,700 estimated! Thank you again!

Maj. Dundee

The original relays (grey) were made by Tyco. So see if you can get Tyco or Bosch or Hella. don't start buying unk brands just because of price.

RNotamechanic

I did purchase an identical grey part at Mercedes...initially they told me the cost was $37. I told them I had seen it at MBonline for about $20 and asked what the difference might be. The parts guy said well, we can charge what we want to. Then he came back with the part and charged me $25 for it! What is up with that! Anyway, I got it in the car and everything works perfectly now! Am afraid to go back to the dealer for service, though, so will see if I can find a good alternative. Also wonder if I should wash the blue stuff off - is it corroding anything? Or would that make matters worse? We are expecting up to a foot of snow tomorrow, so that will wait for a sunny spring day!

Thank you so much, Maj. Dundee!

RNotamechanic

Does anyone have a fuse chart for a 1999 ML 320? Just got the ABS pump fuse working, and now the back lights that illuminate the dash went out. Replaced one fuse and the backlight came on when the car started, but went out when the headlights were turned on...so something else needs fixing! Help is appreciated!

Maj. Dundee

The fuse/relay chart is on the back of the cover.

Swo7pes

I will follow this this and let everyone know the outcome.