BAS/ESP and ABS lights and limp mode?
 

Helllo guys.

I recently bought a 2000 C180 (M111). When I turn the ignition on the BAS/ESP and ABS lights go on. They stay on also when I start the engine, They never go out. The car starts but it seems to be in some kind of limp mode. Would that be possible? If I rev it fully it seems like it is almost choking it self to death. It is impossible to rev it more than 2000 rpms with the accelerator fully pressed. If I press it very gently it is possible to rev it a bit more. It is almost impossible to drive the car because it lacks power. I have tried the following things.

1. Put in a new 100Ah battery and measured charging at idle. 13,7 volts.
2. Installed a new wheel speed sensor, right front wheel, The previous owner said a garage scanned the car for error codes and that was the only one.
3. Changed all the brake pads and adjusted the brake fluid level.
4. Installed a new brake pedal switch.
5. Inspected the third brake light, Seems totally normal. All brake lights work perfectly.
6. Tried to start the engine, turn the steering wheel slowly all the way to the left, then all the way to the right and then to the middle position. This is said to work sometimes as a reset.
7. Tried to disconnect the battery and merge the + wire with the - wire using a jumper cable.
8. Checked the ESP fuse under the hood. No problem.

Nothing helped. Unfortunately the car has OBD1 so I can't scan it for error codes myself. Do you have any other suggestions to fix my problem? Thankful for all help.

Could it be that the previous error code needs to be cleared with a scan tool?

/Johan

Unplug your MAF and see how it runs/revs unplugged.
Did you clean your MAF ? (you did everything else, except this cheap, inexpensive to-do check....)

With your obd1 scanner, any codes saved and read?
You will need a 38 pin adapter and sounds like you need an improved/better scanner like an autel or foxwell with correct 38pin adapter to scan from under the hood. (cheap investment consider the
age of these runners.)
And yes, you need to clear the codes to see if it comes up again.

Hey! Thanks for your reply. Much appreciated. I tried to unplug the MAF sensor. The car ran worse, almost not at all. It wouldn't idle and almost didn't rev. So I'm guessing the MAF is not the problem.

I have a iCarsoft i980 OBD2 error code reader. I also have a 38 pin adapter, a chinese cheap version bought on eBay. I'm not sure if this will work but I will try it. The wheel speed sensor error code was diagnosted by a workshop. Please recommend another setup if you know something you know will work on a W202 for sure.

Thanks again!

If you pulled it, I hope you also cleaned it with MAF cleaner and checked the intake line for any oil film.
I hope your cheap 38pin works.
What was the code? Post all saved codes.

I only unplugged the connector not the MAF itself but I will try that tomorrow. I don't know what the error code was. The precious owner only told me it was the wheel speed sensor on the right front wheel.

I think I will check out the throttle body as well. They can often cause problems. And I think it's possible that it could light up the BAS/ABS and ESP light even if it sounds crazy.

ok gotcha.

Check the maf wiring cable too, to see if any internal wiring has disintegrated or broken. This can cause the issues you mentioned.

Here's a good DIY on the wheel speed sensor:

Hey! Thanks again for your reply :) I couldn't wait so I tried the adapter and then my code reader and it actually worked! I got two error codes. "P0100 - Mass or Volume Airflow A Circuit" and "P0110 - Intake Air Temperature Sensor 1 Circuit".

I forgot to mention that I smell gasonline but I have inspected the fuel filter and the fuel pump, there are no leaks. Not any leaks from what I can see. Also sometimes when I press the throttle there is a slamming sound. I would be surprised if the MAF is the only problem here.

Also, if the MAF is the problem, shouldn't the car run good better when I unplug the connector?

With the MAF cleaned and plugged in as usual, clear the codes and trial run it again. See if the 2 codes come up again.

The car starts up ok?


Edit: forgot to add this - for your bookmark - good reference.
Since your in sweden, right? forgot to ask - what's the outside temps and what does the gauge temp show?

Hello again!

So I cleaned the MAF and also a bit of the throttle body. It felt like the car ran a bit better but the throttle response was still bad. I also found some ground points that looked a bit corroded so I cleaned them aswell. The codes for the MAF disappeared. I tried to rev it real hard and then it began to misfire. So I got codes for all cylinders misfiring. After deleting them I thought I would try to drive the car a short distance only pressing the throttle gently. At one point when I braked suddenly the two warning lights for BAS/ESP and ABS went out! Great! The car drives but only on low revs. I'm guessing there are two separate faults. One is the warning lights and the other that the car won't rev. I made a short video so you can see the throttle response for yourselves. Right now there are no error codes found.


As you can see it revs when I increase the revs very gently and slow. When I floor it starts to run worse and then revs are lower.

Any suggestions? Gas pedal position sensor?

When I unplug the MAF the car dies almost immediately. I find that a bit strange, it should be able to idle with it unplugged shouldn't it? Anyway maybe tha fault is not there.

Hey! The car always starts up right away. No problem there. Outside temperature today was about 18 degrees Celsius or 64 degrees Fahrenheit. The gauge showed very close to this.

Hey again. I think I will take a chance and order a new Bosch MAF (even though it's expensive), a set of sparkplugs and a new air filter after all. I've read that a broken MAF could cause these symptoms even without making a fault code.

Your description and video - on the hesitation of acceleration tells me it's a MAF issue (the sensor) or possibly the throttle body.
Correct, I was gong to suggest a replacement MAF (as you already discovered) but make sure its OEM, not a generic knock-off (plenty of discussion on this oem vs non-oem key components).
I would also recommend you pickup a bottle of seafoam and dump some thu the vacuum line (that connects to the brake booster). Do a search on this. This will give your m111 some love (and big billow of white smoke).

Hello again!

Thank you very much @khomer2! You were right, changing the MAF solved the problem :) Now the engine runs great and the throttle response is perfect :) So nice with the W202, two minute job :) I actually ended up not buying a BOSCH but a "Johns Autoteile" one. German as well. This one was like three times cheaper than the BOSCH. It only had the reference number for the specific original MAF so it's not a universal one, it seems to be made for this engine only. It works great and comes with a two year warranty as well.

Again thank you very much for your help, now I can focus on other easier and funnier tasks when it comes to the car.

I'm sure I will be back here again. Until then I wish you guys all the best :)

Glad to hear the swap went well. Please keep us posted on your longer term results with this non-oem maf replacement.
Always good for the members to know of these options that are available.

Happy Driving. :zoom: