A Class 170CDTi W168 Semi-Auto Problem

[Jonny A Class]

Hi Guys

Got a bit of a problem on my wife’s A Class, I’ve just got myself and new car and given the A Class to my wife.. anyway after a month the semi-auto gearbox has stopped working.

We have a W reg 170 CDTi with the Semi-auto gearbox, the one with the manual stick but no clutch.

All has been fine with the gearbox, but yesterday the car just stopped mid-journey with a F showing on the dashboard LCD display... the car will only start when you press the break peddle but will not go into gear, however when the engine is off the gears feel like they select fine.

Does anyone know of anything this might be... other than a mechanical gearbox problem.

Thanks

Jonny

 

[mattkh]

Got a bit of a problem on my wife’s A Class,
All has been fine with the gearbox, but yesterday the car just stopped mid-journey with a F showing on the dashboard LCD display..Jonny

Hi
Anything in the owners book about the F on the dashboard.

 

[Jonny A Class]

Hi
Anything in the owners book about the F on the dashboard.

just that F means fault .... very informative! the only bit of good info was tnhat yuor could start with the break pressed, but that didn't help as the grearbox will not select a gear.

 

[jibcl500]

theres an ECU for the gearbox £100 I think from MB, some diagnose the gearbox as needing replacing when in fact its just the ECU, best get it diagnosed first and go from there.
Also I think the air flow meter can have something to do with it, have a look at http://www.aclassinfo.co.uk/mypage.1.htm



jib

 

[Jonny A Class]

theres an ECU for the gearbox £100 I think from MB, some diagnose the gearbox as needing replacing when in fact its just the ECU, best get it diagnosed first and go from there.
Also I think the air flow meter can have something to do with it, have a look at http://www.aclassinfo.co.uk/mypage.1.htm



jib

Thanks i'll see about getting that checked, that www.aclassinfo.co.uk website had a link from MAF page to a place that can test ECU's for £35.

I found a great link on another forum saying it might be the auto clutch actuator which is a £10 repair.

 

[jibcl500]

The engine ECU and air flow meter are combined, I think MB charge about £900 for a new one, I think they are also coded to the car so one from another car wont work. I could be wrong though.

Find a good indie in your area and get them to have a look, then go from there.

jib

 

[Jonny A Class]

The engine ECU and air flow meter are combined, I think MB charge about £900 for a new one, I think they are also coded to the car so one from another car wont work. I could be wrong though.

Find a good indie in your area and get them to have a look, then go from there.

jib

I'm going to have a look at this at the weekend first;

http://www.benzworld.org/forums/w168-class/1329207-semi-automatic-problem-no-clutch.html?highlight=semi+auto

Then ask the very local indie Merc service centre to take a look.

Jonny

 

[Jonny A Class]

Kind of have some good news, that link I found on another forum for the ACS pump looks to be the problem (maybe). I've taken the wing off and with a gentle tap on the pump the gearbox works for a bit and then after a number of gear changes the F is reported on screen... again a little tap on the pump fixes the problem.

I'm going to take a look at the pump tomorrow.. anyone know of any other things i should be looking for.

Ta

 

[mattkh]

Kind of have some good news,Ta

Hi
Good luck.
Take some photos for us.