C220 CDI W202 BAS/ESP Comes on

[Alex Crow]

hello mick, your fault codes could suggest a lateral acceleration sensor, not uncommon to give intermittent faults. a live test on the star machine would help, do the c1142 AND the c1140 codes always come back then?? with the same number of occurences as each other? i will check the wiring tomorrow if i get time.

 

[Mikimogo]

Hi Alexander;
Yes usually both the codes come up together on the rare occasion after clearing the faults the C1142 Lateral Acc sensor shows on its own but it is soon followed by C1140 Steering angle sensor. I did notice when looking at these faults on WisAsra it says not to go changing the Steering angle sensor or ESP ECU as it is very rare for these to be at fault although it is possible for the supply to these to be at fault which will show a fault at the component. The Esp light was on nearly all the time until a couple of weeks ago when I turned fuses 28 and 30 around and then it stayed off for almost a week then came on again but not as often, and last week I checked the voltage at the Lat acc sensor which was ok and took the lat acc sensor out to inspect it but after I put it back in the ESP light stayed off for 3 or 4 days. What I am trying to say is that by disturbing these it seems that the frequency that the light comes on less often. What baffles me is that the light can be on when I turn off the engine but when I next stsrt it to go out again the light is off, without any re-setting or re-initialising the steering angle sensor. I have tried to figure out the wiring diagram in WisAsra but although I can follow the circuit I cannot follow where the parts are located as I can't sem to find in WisAsra where the parts are situated on the car apart from the Latt Acc sensor and Steering angle sensor.
Thanks for your valued assistance Alexander.

 

[television]

If the ESP does not need re setting after the lamp has come on, then to me this looks like a CAN signal not being picked up, the connectors particularly on the steering can get poor connections,,this fault is listed for many cars

 

[Myros]

Mick I have pm'ed you

have a look in your in box

 

[Alex Crow]

as malcolm says, if your steering angle sensor does not need resetting, this means the power supply to it is fine and not an issue. i have checked the wiring regarding commonality between these two components and can see no obvious links. the codes you have will have further definition, eg c1140-003 etc, this would tell us more...

all that said however, you could just have a glitchy latt accel sensor which is causing the strng angle sensor to come up as well, this would be my guess. probably 5 minutes with a star machine would pin it down. if the car sees lateral acceleration with the steering angle sensor showing straight ahead, it will not necessarily know which to believe. you can see where i am going with this.

 

[Mikimogo]

Thanks Alexander and Malcolm,
I have taken the Steering angle sensor out and cleaned the contacts and then put it on the diagnostics again And it came up with the C1142 again so I cleared the memory and it showed memory cleared I then run it again and it showed stored fault C1142 actual fault Nil so I have cleared the memory again and it now shows Stored fault Nil Actual fault Nil so I am going to give it a run out on a job now so I will check it again in the morning. I am beginning to think that as it was showing Steering angle sensor and Lat Acc Sensor with the wheels pointing staight ahead it may well be as suggested a glitch in the Lateral Acc Sensor. I have sourced a Steering angle sensor so I will have to find a Lat Acc Sensor and go from there. We'll beat it yet!
Thanks everyone for the input.

 

[agadza]

Hi Guys,
Have had the same problem (BAS/ESP light on) for a good year plus and after spending heavily, (including £100.00 just to have a steering wheel taken off!) the problem still remains. I would like to try the fuse strategy. Any one know which ones I should be looking at for a W202 C200 (year 2000)?

 

[Alex Crow]

hello agadza, what fault codes do you have? did you know it is absolutely critical to have the steering wheel correctly aligned in the straight ahead position?

 

[agadza]

Hi Alex, This is my story: sent carin to have rear brake discs changed. One day later the BAS/ESP light comes on. I took the car back and the first thing they tried was the stering angle sensor replacement.they said they had to ensure it was not a disconnected wire so they had to take the steering wheel off. then they said get new rpm sensors. then they said do a four wheel tracking. the steering wheel points straight ahead now and on a flat road the car moves in a straight line. I came across this thread and think the fuse change/swap might just do it. Happy for any other suggestions, though. cheers!

 

[Alex Crow]

changing parts is great, but the way forward for you is having a fault code and live data analysis check. the rpm sensors can be checked very accurately before they are changed, with the correct computer, and shold not be changed without a recognised problem!! if it is a fuse (power supply) problem, this too will show up on the computer. where are you?

 

[agadza]

in south east london, mottingham to be precise. somewhere near eltham.

 

[Alex Crow]

any recommendations for s/e london? anyone?

 

[agadza]

Very sad, Alex, but this confirms what I have experienced. No reliable merc indies in the south east of london area. ( I have been to all the unreliable ones!) I guess I will have to resort to the fuse trick and see if it solves this. thanks for helping.
But back to my original question: does anyone know which fuses in particular I should be paying attention to on a year 2000 W202 C class?

 

[Miffy]

Yes, a good indie in Sidcup, just up the road from you Agadza

the indie is Andy 020 8308 9175

http://www.merc-techuk.co.uk/

 

[television]

Fuse block D

ESP fuse 28 5 amp

block E
fuse37 for ESP pump 40 amp


But as Alex,, changing parts without knowing if they are faulty or not can create lots more problems and faults

 

[agadza]

Many thanks, guys. Will let you know how I get on on both counts.
Miffy - does Andy use this forum? This is cos I have seen a few requests for a reliable indie in the SE london area go without an answer. Will check him out. Thanks.

 

[Mikimogo]

C220 CDI W202 BAS/ESP Comes on (NOW OFF)

Sorry my update has taken so long but the problem has been ongoing. Having checked every thing and run out of places to look I decided to change the steering angle sensor and found that mine had a hair line crack barely visible but definitely there so I transferred the clock spring on to one that a very kind friend supplied me with, I didn't have to centre the Clock Spring as I left one screw in by a couple of threads and undid the 4 plastic catches round the inside so the clock spring comes out complete. When I reasembled everything and tried it the light stayed out for about 2 weeks and then came on again but no where nearly as often as with the old sensor in so the old sensor was definitely faulty. I then noticed that it was now only coming on when the steering wheel was at about 5to as on a clock so when I got chance to dismantle the steering wheel again I measured the gap between the s/angle sensor and the clock spring which should be at the max 5mm but at one point it measured 8mm so I hunted around for a clock spring (Mercedes would only sell the complete unit so I left that option as a last resort) I managed to find the correct one about 3 weeks ago but with the weather being so lousy I left it until I had a week off at Christmas. I have now replaced the clock spring and so far the light has not come on at all therefore it proves that it was in fact both parts that were faulty as when I have since as a matter of interest rejoined the old clock spring onto the old S/Angle sensor the warp on the clock spring matches up with the hair-line crack in the S/Angle sensor, so it looks like someone previously had tried to get the S/Angle sensor unit out without getting any advice on how to do it and damaged both parts which in time has taken the gap outside the gap tollerence limit of 5mm.
Would you believe it has taken me over 12 months to sort that out.

 

[television]

Isnt it nice though when the fault has gone,,you drive just waiting for the warning to come up when it has been there a long time like my ABC lamp, after having it come on for 2 years at any time I miss it now,,I wonder how long I will have to drive the car before i forget all about it

 

[Milwatch126]

2001, w203, class coupe also has BAS/ESP Comes on constantly, HELP ???

Hi All,
I also have this problem after some work on my passenger side bearing and shock along with the replacement of both side front arms.

My local Dealer told me I need to replace a sensor box on left hand side of my engine .
Then it was a wiring loom that runs along that area ?

Can anyone tell me where I can find these fuses?????????????

Cheers,
M

 

[CrazeUK]

Not Sure if this has been mentioned.

I found that My ESP light came on even when my drivers side front tyre was a bit low in pressure.

It went off if i filled it.

The other day i had the car tracked and tyres changed, now the ESP Light wont go off.