Weird limp mode when towing - electrics or something else??

[Xtractorfan]

Just a guess, but worth a check, your year of car and earlier had a problem with oil seeping into the wiring loom and wicking up into the gearbox ecu... A quick check of the ecu will confirm if it is oil saturated.... The cure is to wash out the ecu with switch cleaner or lighter fluid and blow dry, then fit a new seal to the gearbox loom connector.

 

[joderest]

my w163 did this to me suddenly, no power, sluggish, would not change gear. It turned out to be the pipe that feeds suction to the TURBO ACTIVATOR had come adrift, hence no turbo being activated.
I mention as some have said same thing here, my repair was simple, pushed pipe back in, no cost.
It may well be the activator is getting stuck

 

[Fiona/Trevor]

Update - been in Edinburgh for 2 weeks.
Weirdly, it was perfect all the time we were away, down to Edinburgh and back twice, then as soon as we came home it went into limp mode on the hill now named 'limp hill' coming out of Inverness just passing the Drummossie Hotel on the A9 south.... six out of the last seven times, it's been just there in exactly the same place, which is a long steady hill, which may be a clue to something.....
Turbo actuator is being replaced this week.
I have no idea what diagnostics equipment they have been trying, hubby takes it there and has never remembered to ask!

 

[Fiona/Trevor]

it defo reads like the turbo actuator is failing , my 221 needed one a couple of years ago doing the very same thing but I have MB2 so could locate the problem easily , you still haven't confirmed just what these garages are using for diagnostics pal ??

Wish I could tell you - hubby takes it there, to about 5 different garages now over the last year, and I've never been able to get him to remember to find out! only that they have 'all the right stuff' which clearly isn't helpful!

 

[Fiona/Trevor]

Right- long delay due to long trip away- but the day before we left, the garage changed the actuator and we've since done 2,500 miles, including 1000 towing the caravan, and it hasn't gone into limp mode once - so I guess that was it! Phew!
Thanks for advice