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ABS + ETS but no fault codes so is it Brake Switch?
My wifes C Class W203 has just got the ABS and ETS warning lights on dash, I ran a code check and no faults were found on ECU, so I am thinking it’s the brake pedal switch, do you agree? IS there anything else I could check?
Was the battery disconnected? If so turn the steering lock to lock. Did you scan the ESP for faults? It should store a stop lamp switch fault if its faulty.
A little while ago I had the EPS error and after a few scares I disconnected it in the back and bought another used part. Around those few days the BAS came on too. I thought they were connected but they weren't. For BAS to go away (and for me to get cruise control back) I had to replace the brake light switch.
The ABS / ETS lights stay away for a day but then have come back however when I plug in my OB2 scanner I get no faults?
I had a look for the brake switch but was surprised to see that where is should have been there was nothing? Is this normal? See photo.
I've also read that if the battery is weak it can trigger the lights. I dont recall the battery dying but tried the steering when left to right still but no joy.
The ABS / ETS lights stay away for a day but then have come back however when I plug in my OB2 scanner I get no faults?
I had a look for the brake switch but was surprised to see that where is should have been there was nothing? Is this normal? See photo.
I've also read that if the battery is weak it can trigger the lights. I dont recall the battery dying but tried the steering when left to right still but no joy.
Ah yes, mine had me confused as well. Take off the dashboard fuse cover for more light. You are looking for it in the right spot, it just isn't easy to see. I expected it to be dead straight in the centre but it is higher up and on a funny angle. Feel your way up the brake pedal 'column' and it will be right above that, mine was in a black plastic housing. Hint, pinch the release lever and twist to the right to remove. The new one will be a lot more stubborn to go in than the old.
There is no switch on your model. Scan the ESP system. OBD scanner useless in your case
Just an update, the ABS / ETS lights were off for a while today then came back on. I ran the code check and still shows no ABS sensor errors, so I am thinking it’s the brushes in the ABS motor or a bad solder joint on the ABS control module. My question is, if the control module needs replacing can I buy a used one on ebay as they are pretty cheap and plug it straight in without any coding so long as I get the same one for the model and year of my car?
the obd2 standard code tester wont check for brake issues... you would have to connect the more complete MB start system for that. if it does.
best you go to the dealer or indy that can test it... tell you whats wrong.. wheel sensors, module. etc. trying to guess wild stuff like solder joints is conspiracy theory territory. look for easy stuff before you think of such complicated diagnosis
the obd2 standard code tester wont check for brake issues... you would have to connect the more complete MB start system for that. if it does.
best you go to the dealer or indy that can test it... tell you whats wrong.. wheel sensors, module. etc. trying to guess wild stuff like solder joints is conspiracy theory territory. look for easy stuff before you think of such complicated diagnosis
So I checked all the things I could think of today before I take it to a garage to get the codes read next week.
I've checked each ABS wheel sensor and their Ohms readings were all around 420KOhms and if I reversed the meter probes I get about 6.4 M ohms, I also have a spare sensor and get the same readings, so the fact that all 5 sensors have similar readings tells me they must be okay?
All plug connections look dry and clean with no corrosion and no damaged cables.
I removed the ABS motor and control unit which also look good, however the motor was sealed so not sure about worn brushes ?
I was thinking the hub teeth could be corroded at one of the sensors however the dash lights come on straight away before I move, so would this mean it's something else?
Gut feeling is new control unit but I will see what the codes tell me next week.
With all your so called checks you end up building more faults in the system than before, it can be anything from power supply to steering angle, yaw or lateral sensor. It could be nothing at all and the faults just need to be cleared. So take some good advice and leave what's not broken alone until you scan the ecu.
Good luck
Hey guys I'm new on this. Can someone tell me where I can go to start a new thread or maybe u guys can help me. I have a w203, 05 c230k. The radiator had a slow leak for the last few weeks. I'e Just been adding pentafrost coolant with water. So I'm driving and it said to add coolant. Trying to change radiator i saw the the upper lines were rusted. Long story short I broke the lines and had to order new ones. Got the new ones in but forgot how to put them in. Did take pics or anything, what a dumbazz move. So I need help putting it back together. I don' know anyone that works on Benz but dealer wants 2k. Plz help with diagram and video
With all your so called checks you end up building more faults in the system than before, it can be anything from power supply to steering angle, yaw or lateral sensor. It could be nothing at all and the faults just need to be cleared. So take some good advice and leave what's not broken alone until you scan the ecu.
Good luck
I got the codes read today and I have taken photos of the 3 pages !!.
Where do you think I should start?
(Gut feeling is the ABS control module)?
2 things I have checked already are:
Ohms reading for each sensor of which they all have the same so should rule a bad sensor out, although could be the tooth ring on th hub?
Replaced car battery to ensure good voltage, I have also reset the abs lights by turning wheel left right, they come back each time after about 10 mins of driving.
(Sometimes the lights are on to start on the dash, will then go off after 30 secs but come back after about 10 mins.)
C1122 MIL ON + Stored (left rear speed sensor) signal fault.
C1174 MIL ON + Stored N49 (steering angle sensor) not initalized.
C1162 MIL ON + Stored B24/15 (rotary speed and lateral acceleration sensor) zero point variation rotational speed
C1160 MIL ON + Stored B24/15 (rotary speed and lateral acceleration sensor) electrical fault rotational speed
C1210 MIL ON + Stored terminal 30 undervoltage
C1102 MIL ON + Stored L6/1 (left front speed sensor) carry out visual
C1101 MIL ON + Stored L6/1 (left frot speed sensor) signal jumps
I know the Bosch ABS system pretty well.
My advice, is to leave the ABS controller alone.
Then again, replace it if you want. Imho, it likely won't make any difference. But, someone else would appreciate the profit from that sale.
You list your rough location. :-)
I see that you're in Scotland. Yes, that makes a big difference.
A few things:
A) You must properly clear the codes. You need to do that with a scanner that can clear the ABS codes on an W203.
Or, just make other people richer, by buying stuff that you don't need.
B) You'll likely need a scanner that shows real-time errors and data for the MB W203 ABS system.
An ABS scanner that works on a '95 GM car is nice, if you have a '95 GM car. So, if you buy another scanner, that's fine. Then, also buy a car that it's useful for.
I'm pretty sure that the iCarSoft MB scanner shows what you need. My car is sleeping for the next few months, and the battery is disconnected.
So, I can't say for sure that it does shows real-time data for the W203 ABS system.
It's ~$150 in the USA. Imho, at ~$150, only a fool in the USA would try fixing or diagnosing problems without something similar or better.
There are a few options for scanners. I don't remember them off hand. And, imho, a number of threads have so-so/poor/incorrect info.
I think that the ?????-app may also show real-time data. Search the forums. It's cheap (not free), and just needs a good bluetooth OBD-II dongle (again, pretty cheap). And, an Android or iPhone, of course.
If the iCarsoft MB is too much money in Scotland, I'd suggest trying that app.
C) Or, replace
The ABS unit with a brand new one.
The Yaw sensor.
The steering angle sensor.
Then, get the steering angle sensor properly initialized.
And, all four hubs with MB Brand hubs bought directly from a Dealer, or a reliable source. Fwiw, some National (as in Nation-wide, not as in a store name) Auto parts stores in the USA bought and sold fake wheel bearings (and other parts). So, *I* now buy stuff like that only from a Dealer.
For my GM car, I had to replace two hubs. One was bad, the other wasn't far behind. I bought 2 "Delco"(GM) hubs from a place other than a Dealer. Both hubs went bad within 7 months! So, I spent $$$, and bought the hubs directly from a GM Dealer. Now, it's been over 10 years and many miles, and the Dealer-bought hubs still work fine.
I mention about the hubs in more detail, because it could be that you need two hubs.
But, without fully clearing the code, and making sure that the battery wire, the steering sensor, and the yaw sensor are fine, it's hard to say with seeing a video of live wheel data when the DTC is set.
It could also be the wires. Wires rubbing, with the loom worn, or bad/broken/intermittent can be the problem ~~10% of the time. For GM cars, the ABS wires that connect to the control arms, can go bad or become intermittent after 10+ years.
Even with live ABS data, it may be hard to say if it's the wire or the hub/sensor. Bad wires "often" show good, then nothing. While bad hub/sensors "often" have data (speeds) that vary a lot (verses the other wheel speeds).
I know the Bosch ABS system pretty well.
My advice, is to leave the ABS controller alone.
Then again, replace it if you want. Imho, it likely won't make any difference. But, someone else would appreciate the profit from that sale.
You list your rough location. :-)
I see that you're in Scotland. Yes, that makes a big difference.
A few things:
A) You must properly clear the codes. You need to do that with a scanner that can clear the ABS codes on an W203.
Or, just make other people richer, by buying stuff that you don't need.
B) You'll likely need a scanner that shows real-time errors and data for the MB W203 ABS system.
An ABS scanner that works on a '95 GM car is nice, if you have a '95 GM car. So, if you buy another scanner, that's fine. Then, also buy a car that it's useful for.
I'm pretty sure that the iCarSoft MB scanner shows what you need. My car is sleeping for the next few months, and the battery is disconnected.
So, I can't say for sure that it does shows real-time data for the W203 ABS system.
It's ~$150 in the USA. Imho, at ~$150, only a fool in the USA would try fixing or diagnosing problems without something similar or better. https://www.amazon.com/gp/product/B015DNAMT2/
There are a few options for scanners. I don't remember them off hand. And, imho, a number of threads have so-so/poor/incorrect info.
I think that the ?????-app may also show real-time data. Search the forums. It's cheap (not free), and just needs a good bluetooth OBD-II dongle (again, pretty cheap). And, an Android or iPhone, of course.
If the iCarsoft MB is too much money in Scotland, I'd suggest trying that app.
C) Or, replace
The ABS unit with a brand new one.
The Yaw sensor.
The steering angle sensor.
Then, get the steering angle sensor properly initialized.
And, all four hubs with MB Brand hubs bought directly from a Dealer, or a reliable source. Fwiw, some National (as in Nation-wide, not as in a store name) Auto parts stores in the USA bought and sold fake wheel bearings (and other parts). So, *I* now buy stuff like that only from a Dealer.
For my GM car, I had to replace two hubs. One was bad, the other wasn't far behind. I bought 2 "Delco"(GM) hubs from a place other than a Dealer. Both hubs went bad within 7 months! So, I spent $$$, and bought the hubs directly from a GM Dealer. Now, it's been over 10 years and many miles, and the Dealer-bought hubs still work fine.
I mention about the hubs in more detail, because it could be that you need two hubs.
But, without fully clearing the code, and making sure that the battery wire, the steering sensor, and the yaw sensor are fine, it's hard to say with seeing a video of live wheel data when the DTC is set.
It could also be the wires. Wires rubbing, with the loom worn, or bad/broken/intermittent can be the problem ~~10% of the time. For GM cars, the ABS wires that connect to the control arms, can go bad or become intermittent after 10+ years.
Even with live ABS data, it may be hard to say if it's the wire or the hub/sensor. Bad wires "often" show good, then nothing. While bad hub/sensors "often" have data (speeds) that vary a lot (verses the other wheel speeds).
Good Luck!
I'm sorry but your information is a bit confusing . do i still need to clear the codes as sometimes the car has no dash faults. Is this why you think the lights come back on as they are stored?
Summary:
You MUST use a PROPER scan tool that can scan and reset codes for your car.
It's not the price of the scan tool that matters, it's what manufacturer, which cars, and which models that the scan tool is able to read the manufacturer specific codes and information.
The ABS system is very complex.
With the errors shown, only a fool would go and replace "random parts". The cost of a proper scan tool for that car is much less than many of the parts you're considering.
Either get a proper scan tool, or have a mechanic repair the car. Otherwise, you will very likely be wasting money guessing on what to replace.
If you get a used ABS controller, it may not work. So, without a proper scan tool, you could keep on just replacing random parts, wasting time and money.
I'm sorry but your information is a bit confusing . do i still need to clear the codes as sometimes the car has no dash faults. Is this why you think the lights come back on as they are stored?
So If I undersand you, the faults will remain on the ECU and will not self clear but attempting to replace parts etc, instead I need to have the codes cleared only by a device that can do this.
PS I did managed to obtain a yaw sensor (the one that is in thr trunk) and a ABS control module, I tried them both as they take mins to swap, but sadly although the lights were off for a couple of mins, they came back on. I have now but the original parts back on the car and will try to get the codes cleared.
I've had the car diagnosed by a good independent Mercedes specialist and they believe it's the front left 'pick up' ring, which is what is read by the ABS wheel sensor. I took the disc and hub off which is done by removing the caliper and bearing lock nut and I thought I had found the issue as I could see a build up of gunk over the ABS sensor end. However I cleaned it all and reassembled but the dash lights can on when I took it for a drive.
So took the hub and disc off again and looked at the 'pick up ' ring and it looks pretty clean, but has anyone had experience with this part, how to replace it, does it pop out?
Yes. Take a thin feeler gauge and check if the seal is magnetic. Its very weak but its magnetic
Good man, I was wondering how this worked, I thought the ABS sensor may have picked up the bearings inside somehow but didnt think it was correct.
So If the the ring is not magentic when I use a feeler gauge does this means its worn out and should be replaced? It seems odd though as the ring looks to be in good condition and the bearing grease was the original clean green colour still.
Lastely is this a common fault that the pick up ring looses its magnetism?
Drive it with the diagnostic connected and observe the speed signal
Finally managed to resolve the issue !, its been a bit of a school day but I now know a little more about ABS ETS and BAS.The problem was just the front ABS sensor, it had an intermittent fault which is why it was so hard to diagnose as when I had the machine plugged in the sensor must have partially worked.Looking closely at the cable there was a small slit and slight corrosion, which I believe effected the current to the sensor giving the fault. I had attempted to re-solder it but noticed that the solder would not take to the cable which usually means that it is dirty and not as good as new. So I bought a new sensor, I had to tap the old bolt out as it was all rusty but fitted the new sensor and the lights have remained off now !
So in total I have bought the following parts
Yaw sensor £5 (used)
ABS control unit £10 (used)
Pick up ring £10 (new from Mercedes)
Star Diagnostic - £20
Total spend £45
I am currently selling the Yaw sensor and ABS control unit on eBay so should make a small profit and pay for total £45 I’ve spent.
01-16-2018, 03:19 AM
