Mercedez Benz A140 class help!!

[ralph505]

I have problems with de-accelleration, after approx 20 mins driving the ABS, BAS/ESP light comes on the instrument cluster, the car then drops down to 30mph and I cannot accelerate above 30mph. I have replaced the following:
brake light switch, both O2 sensors and wheel speed sensors cleaned.
Still having problems with acceleration. Now the engine management light has come on the instrument cluster. Anyone have any ideas as to what the problem may be? hope it's not the ECU. Any help will be much apreciated,

thanks ralph.

 

[Cole@MBS]

Welcome,

The cheapest next step is to have the fault codes read, Otherwise your just guessing and throwing money at it!

 

[ralph505]

Hi thanks for your reply, I did the diagnostic readings when the problem first started, here are the following codes:

P0335 - Crank shaft position sensor A circuit Malfunction
P0600 - Serial Comm Link Malfunction
P0136 - O2 sensor circuit malfunction Bank 1 Sensor 2

I've cleared the diagnostic codes from the code reader, Since engine management light came on I have more fault codes:

P0170 - Fuel Trim Malfunction Bank 1
P0130 - O2 Sensor Bank 1 sensor 1
P0136 - O2 Sensor Circuit Bank 1 Sensor 2

Cheers Ralph

 

[markodu]

Hi,
have you managed to fix this, i have just bought a A140 as well and getting the exact problem, I have left it at a garage and wnat to know what the problem might be?

 

[ralph505]

Hi, no I havn't solved this problem yet, still seeking help. I am now going to try the mass air flow sensor. If I solve the problem I will post back and let you know.

 

[faulkner9]

hey dude, i had the same problem when i first bought my a140, i was told that it had a bad air mass flow meter on it and had the ECU refurbed as its all in one cluster, this seemed the fix the problem for a year until this friday when the car has broken down again, this time not the same as the first which was like yours, but instead totally cutting out, the point of this is that again the BAS ESP shows up like yours and the crank sensor has also shown up this time, so i would advise both of them being checked out, as i said the first time i had your problem, the ECU was done and iv travelled about 4000 miles over the last year with no problems so id say that would be the first but most pricy route to possibly sorting it but i am wondering if the crank sensor is related in some way as its shown up on mine aswell.

ps iv got a thread on atm checking out where the best place to get this sorted would be and i see SAM has replied to your thread and mine and has given me a place to check out, might be wise to do the same thing

 

[Cole@MBS]

Forget the crank sensor fault guys, its only logged due to the engine cutting and missing the signal, never change a crank sensor on a A,class in all my years of working with MB!!

 

[ralph505]

Thanks for your replys, much apreciated. I think I'm going to get the ECU checked. Do you guys know how much it will cost to get it checked or even refurbished? many thanks.

 

[luders79]

May sound funny but i would say brake light switch!!! had the same probelm a while back on one! would drive fine up to 30 mph then it would not go at all above that like hit a speed limiter! get the traction fault codes read!!

Hope this gives you something else to look in to

 

[stevebez]

Similar issue

I have a similar problem when the car bogs down when trying to accelerate from standstill. Just does not go anywhere for about 3-4 seconds - pretty dangerous.

My fault codes are P0600 and P0335.

Guess time to have the ECU checked out or maybe have the software rewritten? Anyone looked at the connectors being corroded or some dry contacts?

Rgds Steve.

Ah yes mine is a A160 2002 ~40k miles

 

[Pash]

Hi - Newbies first post !
Just bought 2001 A Class with 36k miles on the clock. BAS ESP light comes on with first press of the brake then stays on. Have changed the brake switch hoping for a quick fix but this has not helped. Took the car to a diagnosis reader guy who read the code as c1201. The car also has the intermitent flat spot thing too. Begining to think I have bought a "dog with fleas". My partner is really dissapointed as this is her car. Any help out there to point us in the right direction would be a real bonus. Thanks in anticipation. Pash

 

[Cole@MBS]

If you have changed the switch then i suspect its the travel switch on the servo u/s. i have forgotten its correct name, been a long day!

A star test would show you better results!

Welcome to the forums!!

 

[Pash]

Many thanks for the quick response SAM UNIT - not too sure what the travel switch servo us means.
Perhaps I should search the forum?
Any suggestions on the intermitant flat spots? Or is this defo the ecu thing?
Sorry not too technical. Actually I have seen that you can have ECU's refurbed baa-reman & anotherone I forget the name of.
If I disconected mine & sent for refurb is it just "plug & play" when it comes back or is it back to MB dealer to put back together?

 

[Cole@MBS]

With a 140 i would leave it standard, wouldnt think any gain apart from more engine wear!

i cant remember if its the BAS pressure sensor or ESP travel sensor, been a long week and head is switching off, if you find the servo, has the master cylinder sat on top,!! you will see a switch screwed into the servo, i suspect its that!!

As i said, a short test on star would give you a more correct fault!!

 

[Pash]

Many thanks for clearing that up.
I will have a check in the morning & report back
Cheers for advice

 

[Cole@MBS]

Could always take a photo of said above part on my otherhalf a, class if you get stuck, but not untill tomorrow!!

 

[Pash]

You are too cool & helpful. . . .
Im not going to sleep with you you know !!
In serious - that as realtive newcommer could be real useful
Thanks

 

[Cole@MBS]

You are too cool & helpful. . . .
Im not going to sleep with you you know !!
In serious - that as realtive newcommer could be real useful
Thanks

No problem, might have to pm me tomorrow as i will forget!!!

 

[lofty]

If anybody is thinking of getting their mass air flow sensor re-build/repaired please read my page 38 for detailed information 15% discount available if you mention my site when placing your order.
http://www.aclassinfo.co.uk/mypage.38.htm

 

[Pash]

Cheers Lofty - that is awsome dedicated amounts of work on your site !!!
Many thanks