Second time an ML 270 automatic sticks in Drive

[Tontastic]

It happened again ... cold morning, mild frost. Engine on .... quick scrape of window ... drive away ... sticks in D, won't change gear. Stop car, engine off, back on, problem goes away. No lights on dashboard.

Any ideas? This is the second time this has happened, almost identical scenario the first time.

 

[BlackC55]

It needs a speed sensor in the gearbox.

 

[Tontastic]

Ah! That sounds logical ... is that expensive?

 

[BlackC55]

Is a MB of course it will be. It depends where you go.....

Roughly looking at 350 plus some diagnostic work.

 

[Tontastic]

Well today after a month of this happening once a week it seems to be here to stay... its stuck in 1st (D) and no tiptronic wiggling is going to take it out. Off to the indies to see what they say .... speed sensor in the gearbox sounds sensible.

 

[television]

Well today after a month of this happening once a week it seems to be here to stay... its stuck in 1st (D) and no tiptronic wiggling is going to take it out. Off to the indies to see what they say .... speed sensor in the gearbox sounds sensible.

I think that Black means that a speed signal is not reaching the gearbox

 

[Tontastic]

Independent says several pages of faults relating to gearbox (shorts i thing) and ECU. He has recommended drop the sump and look for any metal in there to indicate bearings getting shaved and traces of debris. Likely need he says is to replace the "Conductor Plate" containing the electronics. There is still an ECU fault after that ...

 

[Tontastic]

Little bits of metal ...

The result of the gearbox sump drop is lots of little bits of metal in the gearbox ... which in his words "not good". One option he says is to replace the gearbox ... "as it might only have another month on it, or six or two years ..." I know which choice I would make! I've gone for the do nothing for now approach ... change the oil and filter and see how long before the fault show itself again, i simply cannot afford to spend several thousand on a new gearbox. If it comes back in a week I know things are bad ... if it lasts a few months without the same fault coming back then perhaps things aren't as dire as he paints.

Advice please ... how much metal could/should there be in the gearbox sump? Is he using scare tactics? What would you do ... its the kids christmas presents he is talking about here!!!

 

[Xtractorfan]

hey I would get that ecu checked, it is the gearbox control module, if it aint working or is contaminated the gearbox wont work..get it checked first, call this guy and tell him ur problems he breaks mercs and knows them inside out..Gerard Molloy in N. ireland 028 3756 8083..

 

[Tontastic]

Well i drove it for another couple of weeks after all of the faults were cleared, ATF changed etc, but no other work done. Took it to a gearbox specialist who read the new fault codes which were ...

P2600 The voltage supply of circuit 87 has undervoltage.
P2602 The voltage supply of the valves is faulty.

B1042 CAN communication fault to brake assist control module

There were no shorts, or ECU problems or anything else. Faulty connection, or just plain dodgy battery perhaps?

 

[television]

I do not know the year of your car, but many cars around 1999 have oxidisation problems on the connector to the ECU in the car, this has the effect of giving lock up and non plausible read out codes, often the CAN wires on the end of the plug being the worst, spraying with a good switch cleaner (non drying) does solve it on a few cars

 

[Tontastic]

The car is a late 2001, whereabouts is the connector to the ECU, is it easily reached? I've never used switch cleaner before, whats your advice on what a good brand/outlet is?

 

[television]

The car is a late 2001, whereabouts is the connector to the ECU, is it easily reached? I've never used switch cleaner before, whats your advice on what a good brand/outlet is?

.

Maplins sell a good cleaner

41 in the link so easy to get to, it s worth a try and quick and simple to do


http://www.detali.ru/cat/oem_mb2.as...GM=716.644&CT=F&cat=04S&SID=54&SGR=080&SGN=06

 

[Tontastic]

I just realised that I had never posted back what happened on this thread ...

To summarise ... the car occasionally went into temporary limp home mode which would reset if i restarted the engine. It finally entered a permanent limp home mode which i was unable to get it out of. An Indepent in Glasgow reset the codes and replaced the Automatic Transmission Fluid and filter having read some of these codes and found grains of metal in the fluid. The only option he could offer me was to replace the gearbox, or just carry on and hope it did not happen again. I followed up a couple of weeks later after it had continued to go into its temporary limp home mode with a transmission specialist who found the low voltage codes.

Following on from a gearbox specialist only finding codes using his star diagnostics relating to sensor voltage I replaced the battery which I noticed had been there since new. Since then it has never entered limp home mode. I know the ATF could still be filling up with metal shards but it drives like a dream so no reason to go exploring for trouble. It would find me soon enough by itself.

 

[Cosworth]

.

Maplins sell a good cleaner

41 in the link so easy to get to, it s worth a try and quick and simple to do


http://www.detali.ru/cat/oem_mb2.as...GM=716.644&CT=F&cat=04S&SID=54&SGR=080&SGN=06

Is item 41 located in the big black box?