ABS and ETS lights on/ I found the problem/LONG - Page 4 - PeachParts Mercedes-Benz Forum

CLLARK1 · #46 04-10-2013, 07:29 PM

After reading the other post. I jumped the relay as suggested.The ABS motor did not respond.I took a hammer and tapped on the motor it started and the lights went out.The motor obviously needed brushes .So I removed the motor from the ABS unit.Only two torx screws hold it on.Be careful and try to leave the end cap bearing in the unit.If it comes out with the motor there is a torx plug on ether side of the pistons that can be removed to enable installation of motor.I took the motor to several auto electric shops before I found one that was willing to replace the brushes as they have to be hand cut.After re installing motor all lights are off.This is a better option than buying a used ABS unit that is likely to have worn brushes and likely to fail. Mercedes had scanned my vehicle before repairs and told me it needed an ABS unit and a ETS sensor which is also very expensive.Save yourself some money and do some trouble shooting.

Formergenius · #47 04-11-2013, 12:43 PM

I acquired my '98 ML320 about 6 years ago. The ABS lamp lit sometime later, and the local MB dealer had "never seen this before", so used it sans ABS for years. I stumbled upon Jim's post, and being an electronics tech, thought I would check it out. The weather was 80f when I resoldered the pc board (2 wire connector). Two days later, even though the ABS light was off, I ran over some icy road to see if it REALLY worked. It did!

Thanks Jim!

Smith007 · #48 01-11-2014, 11:57 PM

2002 ML320 +- 25000km
My BAS ESP - one light only on the instrument cluster remains or stays on while driving.
The only thing I did was change the headlight on the drivers side.
Is it possible I may have disturbed the wring harness running to the ABS motor?
Where about is the ABs motor in relation to what I did?Any advice woud be really great please?

kwmccauley · #49 01-12-2014, 05:56 AM

If the 2000 ML has the same layout of the ABS system as the 1998 ML then then some of the wiring passes behind the driver's side headlight. The ABS pump motor is part of the assembly you can see under the hood with all of the metal brake lines coming from it.
Hope this helps.
Ken

Smith007 · #50 01-12-2014, 10:11 AM

Thank you Ken - kwmccauley For responding
Forgive me I really have to work on my communication skills - I should have said that I changed the headlight BULB but I did reef or disturb the black harness as the little backing plate to the bulb fell down there between the windshield water bottle and the back of the headlight housing and the one harness runs along the side of the headlight and the other underneath housing cover and trust me you will be touching the wire harness along the side to get that back cover back on as the space to work within is so limited and the cover has little pesky tabs.

So I guess the question is whether these wires or wire harnesses are relevant to the abs motor and I could have disturbed an already fragile soldering from way back there in relation to where the pins and the abs motor sits?

My answer is yes it is possible -- (thanks to Ken yes the abs motor is to the side. I always thought it was under the fuse box and the water bottle - but it is slightly to the left between the engine and the water bottle)
POSSIBLE yes as one cannot see the wiring connector or plug to the abs motor.
How would you advise removing the entire headlight housing or the windshield wiper water container or both??? to find the brocken wire area?

Perhaps I should take a picture

safiah · #51 04-02-2014, 02:55 AM

Thanks guys for sharing. I don't know anything about cars, so you can imagine how much money I have spent taking my ML320, which I have had for 14 years to Mercedes. Lately, given I am very short on cash, I have tried doing a few things on my own, and have been fairly successful.

However, now my ABS light is on, and I am told it could be my ABS pump. About two years ago, my wiper fluid leaked, and I believe it might have contributed to my ABS/ETS/BAS lights coming ON; it has been about five months. I have read all the posts on this, and have located the ABS pump on the driver's side. However, I am not sure of the easiest to gain access to the module, so I could verify what, if anything is wrong with it.

Could someone please advise me on the easiest way to reach this module?

Thanks a bunch guys!

Dave289 · #52 04-14-2014, 01:01 PM

I have also got the ABS and ETS lights coming on as soon as I press the brake pedal, and no brake lights on my 2001 ML55.

I checked the brake light switch, both sets of contacts seemed good, but replaced it with a new MB switch anyway - no change.

I have swapped relay K25 over with each of the others around it .... and checked that there is 12V on both sides of the ABS motor fuse.

I am now trying to remove the plug on the back of the ABS module, to check the power cables there. I can lift up the housing of the connector about 1,5 cm, but then it stops and won't go any higher .... and I can't see any clips holding it back, and can't find any other way to pull this connector off :-(

What is the trick here ??

jfreezn · #53 05-07-2014, 11:20 PM

Hi guys!

I can't believe this thread is still going since i started it in 2006! I still have the 98 ML and the ABS has worked fine since I fixed it with a soldering iron.
Reading first message on the first page will help you troubleshoot this. As I read, I note that the 15 pin connector may also be a failure point. Unplugging and re-plugging a connector is a classic fix for MB electrical circuits throughout history! read my comments, paragraph 8 the way i address following this circuit will help you find bad wires, bad connectors, bad solder joints, etc READ POST #! in this thread!

Quote:

Originally Posted by safiah

Thanks guys for sharing. I don't know anything about cars, so you can imagine how much money I have spent taking my ML320, which I have had for 14 years to Mercedes. Lately, given I am very short on cash, I have tried doing a few things on my own, and have been fairly successful.

However, now my ABS light is on, and I am told it could be my ABS pump. About two years ago, my wiper fluid leaked, and I believe it might have contributed to my ABS/ETS/BAS lights coming ON; it has been about five months. I have read all the posts on this, and have located the ABS pump on the driver's side. However, I am not sure of the easiest to gain access to the module, so I could verify what, if anything is wrong with it.

Could someone please advise me on the easiest way to reach this module?

Thanks a bunch guys!

jfreezn · #54 05-07-2014, 11:22 PM

Quote:

Originally Posted by jfreezn

Hi guys!

I can't believe this thread is still going since i started it in 2006! I still have the 98 ML and the ABS has worked fine since I fixed it with a soldering iron.
Reading first message on the first page will help you troubleshoot this. As I read, I note that the 15 pin connector may also be a failure point. Unplugging and re-plugging a connector is a classic fix for MB electrical circuits throughout history! read my comments, paragraph 8 the way i address following this circuit will help you find bad wires, bad connectors, bad solder joints, etc READ POST #! in this thread!

Jim in Phoenix

Dave289 · #55 05-13-2014, 04:33 AM

I finally managed to get the 15 pin plug off the ABS board module, and the module unscrewed and removed from the ABS pump assembly.

The lower two pins on the 15 pin connector on the ABS board module meter out to the relevant two pins on the top of the board with zero resistance and the contact is not lost as the module is shaken or moved, so I think the fault lies elsewhere.

When the engine is running, there is ca. 14V on the fuse for the ABS pump, but only 9V on the hot wire of the ABS module plug, so maybe that isn't enough to run the ABS pump, and I am now off to try and find out where this voltage loss is occurring

Igor Polyakov · #56 05-28-2014, 09:18 PM

Hi Jim,

I have somewhat similar problem with my ML320 1999. Occasionally, all
three BAS/ESP, ETS and ABS lights come on. They may stay or may be gone during the driving. If they stay on when I stop engine, they appear again on
when I start the car but after a short time they disappear. Often I can feel ABS at work at slow speed and after a short time the lights are on again. Occasionally, I also see warning light on.
This story began >1year ago in summer 2013. I visited several (three) mechanics and they could not read codes for this behavior. Unfortunately, I live in a small city and there is no MB dealership here, in Fairbanks. During winter the lights were off, and the problem re-appeared recently, in warmer season.
What can I do in this situation?
Thanks -

Igor

Quote:

Originally Posted by jfreezn

This was on my 98 ML320, other vehicles may be similar.

Since these lights would come on instantly, after starting the engine, I figured I had a hard failure somewhere in the ABS/ETS system. See my previous entry on this subject of a couple days ago.

After checking the 40 amp fuse that feeds this circuit, I pulled the relay, K25, that feeds the ABS high pressure pump. I can test a relay on my workbench and it tested fine. I also noted there are at least 3 identical relays so rotating them into the ABS socket was also an option.

I had a wiring diagram that I got from the Tempe library, which has a free Mitchell repair access. It shows a red wire going from the load side of the relay to the ABS high pressure pump motor and then to ground. Putting 12VDC directly to the load slot of the socket SHOULD have run the pump, but it didn't.

Testing further, I unplugged the two pin connector which feeds the ABS pump and put 12 VDC directly to the motor. By pulling the sheath back, I was able to see the wire colors. Since brown is always ground on Mercedes, I knew to put the plus 12 VDC to the other wire, to insure the rotation was correct.

The pump ran smoothly! I needed to verify that power was reaching the pump assy.

Unplugging the 15 pin connector from the ABS pump unit was a little tricky. The sheath over the plug pulls straight up and then the sheath becomes a ramping device that pushes the connector out of it's socket. My fingers could start the motion but it took a little pliers to get enough grip to release this connector. The bottom two pins were hot and ground and fed through the housing to the 2 pin connector. With my temporary 12 VDC still connected to the relay socket, I found that 12 VDC was indeed reaching the ABS pump assy, but NOT getting through to the 2 pin connector. The problem had to be in the ABS housing somewhere.

NOTE: At this point I found it conducive to remove the driver's side headlight unit for more working room. A 5 minute task to figure out how to release the plastic trim strip under the headlight where two nuts were hidden.

The front of the ABS pump unit appeared to have a wiring acces cover and I got really lucky here as the whole actuator control and wiring came off by removing 4 small 6 point screws. It just slid off the 12 pins that seal the fluid side of the magnet assemblies, No fluid is released and I had the printed circuit board in my hand.

Checking with my VOM connected to read resistance on pin 15 to the pin on the two pin connector that feeds the motor, I found high resistance with considerable fluctuation whenever the pins were flexed a little. BAD SOLDER JOINT! Where have we heard this before? The manufacturer is ATE, a well known vendor, but who knows how many ABS pumps hit the trash can because of a simple joint failure. At $1200 each, I am glad I took the time to find this problem.

The PC side of the board was covered with a 1/4" of clear jellied sealant, easily removed with an exacto type knife. I cleaned the old joints with brake cleaner, then I soldered both pins and in minutes the unit was reassembled and tested. Zero resistance is good! I used some clear silicone to close up over the newly resoldered joints.

Suffice to say that I rejoiced when the engine started and both lights were eztinguished. Knowing that I had ABS again was a big relief too.

I took a few pictures and will try to attach them. If this file is already too big I will send a separate file. Thanks to all who took the time to reply to my pevious note.

Jim in Phoenix

Igor Polyakov · #57 05-29-2014, 12:08 PM

I have somewhat similar problem with my ML320 1999. Occasionally, all
three BAS/ESP, ETS and ABS lights come on. They may stay or may be gone during the driving. If they stay on when I stop engine, they appear again on
when I start the car but after a short time they disappear. Often I can feel ABS at work at slow speed and after a short time the lights are on again. Occasionally, I also see warning light on.
This story began >1year ago in summer 2013. I visited three different mechanics and they could not read codes for this behavior. Unfortunately, I live in a small city and there is no dealership here, in Fairbanks. During winter the lights were off, and the problem re-appeared recently, in spring.
What can you advise?
Thanks -

Igor

Yemi Olukomo · #58 10-08-2016, 07:36 PM

Quote:

Originally Posted by jfreezn

This was on my 98 ML320, other vehicles may be similar.

Since these lights would come on instantly, after starting the engine, I figured I had a hard failure somewhere in the ABS/ETS system. See my previous entry on this subject of a couple days ago.

After checking the 40 amp fuse that feeds this circuit, I pulled the relay, K25, that feeds the ABS high pressure pump. I can test a relay on my workbench and it tested fine. I also noted there are at least 3 identical relays so rotating them into the ABS socket was also an option.

I had a wiring diagram that I got from the Tempe library, which has a free Mitchell repair access. It shows a red wire going from the load side of the relay to the ABS high pressure pump motor and then to ground. Putting 12VDC directly to the load slot of the socket SHOULD have run the pump, but it didn't.

Testing further, I unplugged the two pin connector which feeds the ABS pump and put 12 VDC directly to the motor. By pulling the sheath back, I was able to see the wire colors. Since brown is always ground on Mercedes, I knew to put the plus 12 VDC to the other wire, to insure the rotation was correct.

The pump ran smoothly! I needed to verify that power was reaching the pump assy.

Unplugging the 15 pin connector from the ABS pump unit was a little tricky. The sheath over the plug pulls straight up and then the sheath becomes a ramping device that pushes the connector out of it's socket. My fingers could start the motion but it took a little pliers to get enough grip to release this connector. The bottom two pins were hot and ground and fed through the housing to the 2 pin connector. With my temporary 12 VDC still connected to the relay socket, I found that 12 VDC was indeed reaching the ABS pump assy, but NOT getting through to the 2 pin connector. The problem had to be in the ABS housing somewhere.

NOTE: At this point I found it conducive to remove the driver's side headlight unit for more working room. A 5 minute task to figure out how to release the plastic trim strip under the headlight where two nuts were hidden.

The front of the ABS pump unit appeared to have a wiring acces cover and I got really lucky here as the whole actuator control and wiring came off by removing 4 small 6 point screws. It just slid off the 12 pins that seal the fluid side of the magnet assemblies, No fluid is released and I had the printed circuit board in my hand.

Checking with my VOM connected to read resistance on pin 15 to the pin on the two pin connector that feeds the motor, I found high resistance with considerable fluctuation whenever the pins were flexed a little. BAD SOLDER JOINT! Where have we heard this before? The manufacturer is ATE, a well known vendor, but who knows how many ABS pumps hit the trash can because of a simple joint failure. At $1200 each, I am glad I took the time to find this problem.

The PC side of the board was covered with a 1/4" of clear jellied sealant, easily removed with an exacto type knife. I cleaned the old joints with brake cleaner, then I soldered both pins and in minutes the unit was reassembled and tested. Zero resistance is good! I used some clear silicone to close up over the newly resoldered joints.

Suffice to say that I rejoiced when the engine started and both lights were eztinguished. Knowing that I had ABS again was a big relief too.

I took a few pictures and will try to attach them. If this file is already too big I will send a separate file. Thanks to all who took the time to reply to my pevious note.

Jim in Phoenix

I have been browsing for solutions to my 1998 ML320 ABs/ETS/Brake Light issues on MB Forum but its your write-up that gave me the confidence to dismantle my ABS circuit board today.Your description is so vivid and detailed that it seems I was watching a video demo. Thanks man. I will do the continuity tests and re-soldering too. Hope it also solve my car issue. My ABS pump works fine when I 12volts hard wired it directly. I'll post my results as soon as I re-assembly the module. I look the resources on this forum. Thanks Admin....for accepting my registration. Regards, Yemi from Nigeria.

Yemi Olukomo · #59 10-08-2016, 07:54 PM

Hi Everyone,

I am a DIY. I enjoy doing the grease-money business. I also bought MB-Star 4 with the Dell Laptop last Summer. However, I am handicapped as there is no Repair or Wiring diagram for my 1998 ML320 - Petrol.

Please can someone help me with a downalodable Repair Manual and wiring diagram?

Regards,
Yemi

kwmccauley · #60 10-09-2016, 08:44 AM

Hi Yemi,
Is there a specific procedure you are working on or a particular sub-system you need help with? Or is the request for a complete set of wiring diagrams.
Regards,
Ken