gunar

Hello, I just got '00 ML430 4 weeks ago and few days ago darn BAS/ESP came on. At the begging intermittent, few days latter consistent but with no effect on driving. Took it to MB shop, it took them all day to call back that they found green corrosion inside wire harness connector from B34 where it connects to ESP. They asked to replace wire harness and ESP for $4500. I needed to sit down.

I got DTC codes C1141 (current and 2 more times) once C1140-008, C1529 and C1331-003. Decided to replace connector myself, and start from there hoping that only B34 pressure sensor is causing C1141.

My question is about Brake pressure sensor:
Could it be replaced separately or only when replacing booster A7?
What do C1529 and C1331-003 mean?

Thanks in advance, any help would be appreciated.

Regards,
Gunar

Gullwing

Wow usually when there is something wrong with the harness the tech will price out a new harness and labor and then just offer to repair the few damaged wires for several hours labor even though it only takes 30 minutes.

I think the pressure sensor can only be replaced with the booster. Or is that the travel sensor. Sorry it has been over a year so I am forgetting a lot

gunar

That is exactly what I am afraid of. Not just that MB tech decided to get rid of me by quoting $3500 + $1000 for hands but he also gave me a thought that green corrosion at the connector(s) might be all over. Just like arteriosclerosis, I bought a truck that had no rust on it, unusually clean engine and it drives well but apparently is dying and at this moment I am stuck with lemon.

I am hoping that my "easy way out" might be just N34 pressure sensor having electrical problem. If it measures right than I am really in trouble as A7/7Y1 solenoid valve and A7/7s1 release switch could be replaced only with complete Booster unit.

Are you sure that it can't be replaced without booster?

Thanks for talking to me,
gunar

Gullwing

You can check other connectors for any corrosion.
You can try to clean off the corrosion you can find and see if that helps at all.
If the corrosion is only at the one connector and is really bad, if you are able to get a wiring diagram to see where those wires go and just replace them, run new wires along the harness.
I am not 100% on whether or not the pressure sensor can be replaced by itself.

gunar

Strangely the only connector that had green stuff was the white one, that connects steering angle sensor, various brake booster connections to ESP...

I cleaned but noticed that pin 3 from from first connector of pressure sensor is missing from connector, well it fell off in MB shop while tech was "diagnosing ecetrical problem"... I went mad, cut connector, soldered 16 pin male-female connector from radio shack but yellow BAS light stayed on. I'll still need to get someone to read current DCTs and then I'll be more or less sure.

I honestly don't understand why they wanted to replace ESP unit when all DCT codes points either to faulty connector (random DTC) or to brake pressure sensor (most frequent). Too bad as just week before I had same MB shop to replace spark plugs, transmission oil and clean injectors.

Regards

gunar

I removed corroded white 16 pin connector and re soldered "home made type" but light stayed on. Took me time to find shop that has software to read measurement from ESP and BAS. After reset only DTC that stay is C1141 brake pressure sensor electrical fault. Folks at the shop were very kind to let me read live measurements from BAS pressure sensors (Left and right) and after I wiggled wires second sensor came to life on screen but first stayed off... so a bit of relief, ESP module seems to be alive, but all these wires.

Darn learning curve. I've spend a week searching around for wires, connectors, wire diagrams and how everything works. I couldn't find adequate wire harness to replace all wires going to booster/master cylinder so I made my own and replaced them all, but ESP light stayed on. As I'm not sure if it needs reset at the shop or it is a dead sensor, so I ordered one from MB (didn't have any) and will have to go back to shop to read from ESP again.

After all this crap, I created pdf file of all details that I could find about BAS components and wire diagrams for ML vehicles, so if you ever going to need them just let me know I'll e-mail it.


Thanks for help.

autobasswerner

Hello, if you have not solved trouble, hope this picture will serve you if you let me know as solved

Greetings

guidoq

hi i have similar problems with my 2000 ml430 could you please email me what you have in regard diagrams etc thank you
guidoq

Maj. Dundee

What code/s are you getting?

guidoq

hi scanned at the local garage came up with two DTC cannot remember numbers but one was for Yaw Rate Sensor which i replaced,i also replaced brake light switch,fault still there car brakes on its own without touching brake pedal the other code was something like N32 or 64 or 94

guidoq

hi this one is for Maj Dundee as he seems to be the Guru
i own an ML 2000 model had it for three months after seven minites or so that the car runs or drive i get the first fiur lights on dash BAS/ESP
ETS ABS the Brake light and the Hand brake light all come up at the same time with an audible beep beep i loose the speedometer and the car goes in to Transmission Limp mode as stays in the last selected gear i pull over turn the ignition off restart and all lights go out and car drives fine this seem to be happening first thing in the morning also the other day i started the car left it running while i was washing it and after the famous 7 (seven) minutes all of the above lights come on which i turned off by switching ignition off and restarting, i replaced Brake Switch K25 Relay
resoldered the Pins on the ABS pump card and i pulled ABS motor to check the Brushes they looked good ,i took motor to local rewinding shop they checked it telling me that it looked like brand new put motor back same thing lights back on i rescanned this are the codes i am getting
P0600 CAN of ESP P0500 P1605 CAn Acceleration for poor road recognition P0720 134 sporadic loss of comunication from CAN ESP
Control Module B1041 Can Communication fault to Traction System Control Module previous scans were also picking up C1401 brake return pressure I removed ESP Control Module cleaned Pins and Refitted checked all wheel speed sensors with OHMs meter all ok don't know what else to chek soon i will be rescaning with a C3 mb scanner see if that will place me on the wright direction of what to do next, Maj Dundee what do you think?
i like the car it drives like a dream it has got 132000 km on the clock
can you please help?
thank you
Guido

anam65

My 02 ML500 is doing the exact same thing. Did you ever find a solution? Thanks!

art_arev

Explain your problem in detail.

anam65

My 2002 ML500 is doing the exact same thing as the previous poster's (guidoq). Beeping after 7 minutes of driving and the BAS/ESP, 4-ETS+, ABS, and Brake light come on, the speedometer stops working and it will stay in whatever gear it is in, but all I have to do is restart it and then it works fine for another 7 minutes, until it does it all over again. What the heck?!
When it first started doing this months ago, it would only do it when I first drove it for the day (after 7 mins), then it started doing it a couple times a day. Now it's every 7 minutes!
Has anyone found a solution? Please help!! Thanks!

art_arev

Firstly check your brake fluid level & that your "hand brake" is properly disengaged. The next step would be to scan the car for codes.