ECM /MAS defect on 2001 'A' Class

[lofty]

ECM /MAS defect on 2001 'A' Class

What a disappointment this car is, noisy on the road along with other defects that should have been subject of a recall, Now more trouble this time on my own car.at 31800 miles on the clock.
Car stalls, restarts but engine management light illuminates on dash display exhaust fumes indicate the car is running very rich. Initial diagnostic test by Mobilolife points to oxygen sensor in catalytic converter, replaced at a cost of £150.00 fault does not clear, 2 further pointers to mass air sensor problems which on this model is integrated with the Engine Control Module a further cost of just on £900.00 this item is on order and takes about 5 days to reach the UK in the meantime the car is running fine having apparently overcome the problem, although the fault lamp is still displayed on the dash display, If your car suffers this problem the mass air sensor can be repaired by http://www.bba-reman.of the UK for £250.00 with a 2 year warrantee. Ironic that a new unit from Mercedes-Benz is only covered for a year. Note however that they do not repair the ECM part of the combined module The 'A' Class may have a large interior but from what I can see you its needed to carry the large purse thats required to run it. Good will from Mercedes Nil, Car serviced from New by main dealer. How sad, because I love the car.
http://homepage.ntlworld.com/albert.rowe
lofty My email address in posted on my homepage if Mercedes-Benz would like to get in touch

 

[jberks]

I'm afraid MB don't read this forum. The comments would offend them I suspect.
Fully agree about the recon - its a no-brainer - why pay £900? Especially as 90% of what you'd be buying, you don't need. Th only thing that's gone is the platinum wire in the MAS. The rest of the component is fine I suspect.
O2 sensors and MAS seem to go together - had a diagnostic show the o2 out of whack - 3 days later (whilst waiting for the part) MAS went pop - replaced both (£350 on an E class) and all's been fine since.

 

[lofty]

Update on the ECM/MAS (Engine control module /Mass Air Sensor) problem.
Today I had a new unit fitted cost, a few pence under £900 with the fitting and VAT. The car runs no different to when it had the engine management light showing, it may be a bit quieter, probably due to the mixture being now correct.
The good news is that Mercedes ?Benz have agreed to pay for the oxygen sensor that was diagnosed by Mobilolife as being the cause of the problem in the first instance, They agree it was a fault that is difficult to diagnose but have agreed to pay the £150 that the sensor cost, I fitted it myself.
The lesson I have learned from this experience is to get the car to a Mercedes Garage, get them to do a second diagnostic, test, and i.e. get a second opinion of the fault.
Where something as large as the ECM/MAS is concerned check around and sees if there is an alternative way to get over the fault before committing to purchase parts. In this case there was an alternative outside the Mercedes-Benz service, but I hadn?t made myself aware of it until committing to the new unit, which I understand is coded at the factory and will only work on your car!
The alternative was to have the MAS section of the combined unit repaired by bba-reman.com who charge £250 for the repair, but guarantee the repair for 2 years.
They replace the glass files that measure the flow of air to mixture and recalibrate the unit. The New Mercedes Unit is only guaranteed for 1 year.
jberks thanks for the info, as both have been replaced lets hope that alls well for a while.
lofty