Transmission automatic

[wongl]

Hi Wongl, ive not driven the car enough to know yet but .All i know is the error message came on, and car was in limp mode. I pulled the car to the side of the road waited 5 mins started car again ( no warning message ) and car was no longer in limp. So i guess its not a permanent message wongl.

If your transmission fault is intermittent, there is a high probability that your transmission ECU has broken wires to the connectors causing intermittent communications with the other ECU's in the car. The tell-tell sign is that there will be several errors being logged at once, including one that says 'implausible speed' - essentially the transmission ECU calculates the speed from the gearbox and compares this with the speed from the other ECU's and a broken wire (even momentarily) will create a different speed which causes the transmission ECU to put the transmission into limp mode to protect itself from physical harm.

I suggest you get your car scanned to be sure. The good news is that ECUTesting will repair the transmission ECU for around £250 with a lifetime warranty.

In my experience this is the most common fault with the CVT gearbox - out of 3 W169 I owned (and one W168) this identical fault occurred in the W168 and two of my W169.

 

[Michaell]

If your transmission fault is intermittent, there is a high probability that your transmission ECU has broken wires to the connectors causing intermittent communications with the other ECU's in the car. The tell-tell sign is that there will be several errors being logged at once, including one that says 'implausible speed' - essentially the transmission ECU calculates the speed from the gearbox and compares this with the speed from the other ECU's and a broken wire (even momentarily) will create a different speed which causes the transmission ECU to put the transmission into limp mode to protect itself from physical harm.

I suggest you get your car scanned to be sure. The good news is that ECUTesting will repair the transmission ECU for around £250 with a lifetime warranty.

In my experience this is the most common fault with the CVT gearbox - out of 3 W169 I owned (and one W168) this identical fault occurred in the W168 and two of my W169.

Thank you wongl.
That makes sence and i appreciate all the support on this from all members input. What i did see on the diagnostic machine at a friends garage was that you noted was (implausible speed) and another error i can't remember, thank you for taking you weekend time to give me answers to a problem. Appreciate it greatly

 

[wongl]

Thank you wongl.
That makes sence and i appreciate all the support on this from all members input. What i did see on the diagnostic machine at a friends garage was that you noted was (implausible speed) and another error i can't remember, thank you for taking you weekend time to give me answers to a problem. Appreciate it greatly

If you are getting the dreaded 'implausible speed' error, then take a look at the ECU Testing site - I have no connections with ECU Testing except that I have been a satisfied customer of theirs. Their repairs on the ECU looks very professional and extremely well packaged before being returned to me.

Mention Lofty A-Class website to get a 10% discount.

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Good luck with your gearbox and don't let the naysayers put you off. Having experienced the ownership of 4 W169 in the family (with high mileage), plus experience of ownership of the older W168 for over 10 years, I would say that we never had a mechanical issue with the CTV gearbox. I can say this with confidence over a total mileage of over 300,000 motoring miles!

This is not to say that the CVT gearbox is invincible, but with regular oil services, it can be trouble-free (once the design weakness in the ECU has been taken care of).