Transmission problem

[Sz100]

My old Mercedes A140 Auto (petrol) (2001) is showing a transmission problem (F sign on dashboard) for last few days. It was running very well after doing major servicing in Helford last month. Suddenly this problem appears in the middle of a drive.
Helford don’t to electronics. I called one local garage who suggested to get rid of it as the replacement of transmission box will cost £1000 to £1500. My car millage is 110,000 and online valuation comes about £1,100.00. Is it worth spending further money to diagnose the fault code and if it’s the circuit board problem, then just repair/replace that? Could any expert give an opinion? Thanks for your time.

 

[jibcl500]

Not worth fixing, ECU for the gearbox is inside the gearbox. Mechanically the box might be fine just the electrics.


Needs star diags first to see whats what.

jib

 

[Sz100]

Thank you very much. I'll get the star diagnosis done first.

 

[ZZZZ]

If the fault is this:

Then it's the ECU and for £500 this remarkably helpful chap will fix it better than new - this includes new transmission oil and filter and ECU refurbished by ECU Testing

He really is the best mechanic for W168 and knows the car inside out - can't recommend him high enough.

If the fault is a different one, talk to him - it might be the first gear drum, in which case it could really become not worth fixing, unfortunately.

In the mean time, don't drive it, if you can avoid it, it won't go faster than 40mph anyway, and that will be pushing it to over 4,500 rpm. Also, and that should be a standard practice, don't put it into gear, until your revs drop to under 1,000 rpm - too much pressure on first gear drum, when oil is cold/thick - it only takes 20 seconds or so on cold start.

 

[ZZZZ]

BTW, the sell vs fix dilemma is not that straightforward: with the transmission fault the car is not worth much more than a scrap value, so if it is the FTC, and not mechanical, then definitely fix, even if you decide to sell it after ...

 

[Sz100]

Thanks again. I’ll get the star diagnosis asap.

While waiting for the repair, is it safe to use the car for emergency short drive in the local road at 30 mph? Will this damage anything further?

I had my ECU problem back in March 2010. The MAF sensor part of ECU was repaired that time. Is it the same part controlling this transmission?

 

[ZZZZ]

If, by any chance, you have MobiloLife, then just call them, they will come, run the STAR diagnostics and give you a printout - all free of change, of course.

It'll be OK to use the car for short local runs, just remember the now slightly different dynamics - very slow start from a full stop position, so ease off the brake earlier, otherwise you'll be holding a queue at roundabouts and traffic lights; very light throttle will get you moving faster than hard push / kickdown.

Pretty sure FTC ECU is different, as it is sealed inside the transmission.

There is a [possibly] cheaper way to do it - if you're confident in your local mechanic's abilities: get them to remove your ECU, send it to ECU Testing, get a repaired one back (£195), fit it back in (new oil and filter, of course). Depending on their charges, and whether or not you'd need to recover your car to London W6 (as you won't be able to go on motorway), there could be some savings had. Downside is you won't be able to drive, while waiting for the replacement ECU.

 

[Sz100]

Thanks for the helpful driving tips and guideline on repair cost. No, I don’t have MobiloLife covered. Car is in maidenhead, Berkshire. I’ve asked a local garage and they can do diagnosis only for £60. But they won’t be able to change ecu. I’ll call couple of local garage to see if there is anyone to get the diagnosis and ECU replaced.
If anybody know any Mercedes expert in maidenhead area, let me know.

 

[star]

Thanks for the helpful driving tips and guideline on repair cost. No, I don’t have MobiloLife covered. Car is in maidenhead, Berkshire. I’ve asked a local garage and they can do diagnosis only for £60. But they won’t be able to change ecu. I’ll call couple of local garage to see if there is anyone to get the diagnosis and ECU replaced.
If anybody know any Mercedes expert in maidenhead area, let me know.

Happy to help, but quite away if stuck in one gear.

 

[ZZZZ]

Happy to help, but quite away if stuck in one gear.

Well, just under 15 miles on B3024 is certainly doable, and no messing about with transporter ... It might be the OP's best option

 

[Sz100]

I've found a local garage agreed to diagnose and send the ECU for repair if found faulty. They will test tomorrow. I'll see how it goes. If not, I'll be on B3024.

 

[Sz100]

Just collected the car with test result. Garage told me the ECU is ok, problem is mechanical. Solenoid Valve is faulty (P1841 Valve Y3/7y2 - current pulse width and modulated stored solenoid valve 3 shift - is faulty). They said it might cost £1000 + as one thing might lead other work. Technician will get the quote and let me know. Car was initially stuck in 2nd gear. Now it’s in 3rd gear. Garage wiped out F fault code but this permanent fault will exist.

 

[Sz100]

Just noticed the fault is same as one of the senior forum member mentioned in earlier reply. It seems ECU fault. I don't know why garage said its not ECU fault.

 

[ZZZZ]

Just noticed the fault is same as one of the senior forum member mentioned in earlier reply. It seems ECU fault. I don't know why garage said its not ECU fault.

Well, it's good news, relatively speaking.

The garage wouldn't know, due to lack of experience, and as the fault code says valves, they basically making it up as they go along

You now have to decide which of the options, mentioned above is best for you, but at least it means that, the car is repairable and you won't have to sell it for scrap value.

 

[Sz100]

Star Motor Services (Reading) Mercedes mechanic looked at this problem and redo the diagnosis which gave the same result. The mechanic told me to repair this gearbox ECU including labour ,oil change will cost more then £1500. I'll bring back the car today. I was hopeful to know that with in £500.00 I'll get this problem sorted to use this car to drive and look to purchase for another car. Seems like that's not the case. I've no option but to scrap the car.

 

[star]

Star Motor Services (Reading) Mercedes mechanic looked at this problem and redo the diagnosis which gave the same result. The mechanic told me to repair this gearbox ECU including labour ,oil change will cost more then £1500. I'll bring back the car today. I was hopeful to know that with in £500.00 I'll get this problem sorted to use this car to drive and look to purchase for another car. Seems like that's not the case. I've no option but to scrap the car.

Unfortunely so, there is another repair as discussed but we cannot guarantee that repair, as we have seen mixed results on it. The repair On the valve body is carried out by a third party, we only remove and fit said "repaired" valve body.