Hi all,

Hoping someone can help me with my issue. I Have a 2016 cla amg. before i changed out the transmission fluid, my cars transmission would start over revving and have a "slipping" feeling after about 20 minutes of driving plus the paddle shifters wouldn't work when it happens. Now that I've changed the fluid out it's happening after 40-50 mins of driving with the same symptoms, changes gears after about 2500 rpm and manual mode does not work. Almost like the car has put the transmission into some sort of protective mode. Drives perfectly when cold. When i restart the car drives fine until it senses the temp again I'm assuming.

 

Have you checked if enough fluid was put in after service, low fluid could cause this. Also faulty solenoids or sensors could cause this to happen as well. As for the paddles this could relate to the TCU sensing an issue with the transmission. In reality all of what you’re explaining could be from a faulty TCU. Did Mercedes do the service, do you have a code scanner?

 

I have a cheap scanner that shows no codes at all. And the service was done by my local mechanic so unsure of the fluid level. Would it be possible to check with the oil dip stick?

 

Sadly there is no transmission fluid dipstick with this car... : (

 

Call your mechanic and ask him how much trans fluid he put in. It should be 5.6 quarts / 5.3 litres.

 

The transmission in the CLA 45 is a true automated manual transmission. The TCU works with a shift solenoid to act as a clutch pedal. The first thing I would check is that solenoid, it is right next to the subframe with a heat shield between it and the downpipe.

 

Yup it is basically a manual transmission controlled by a computer, the MCT in the C 63 S is even more so, the DCT in the CLA 45 is "simpler."