I have a 2002 V70 with AW55-50sn transmission and a white sticker Magneti Marelli ETM. I purchased the car used at 93000 miles and it now has 98000 and therefore I do not have maintenance history. My symptioms are that the car feels like the transmission disengages and/or goes into limp mode. I don't know which one it is. This issue started after I changed the transmission oil, which I suspect hasn't been changed in a long time. The disengagement happens more in the city when I am starting and stopping, but it still happens on the freeway. For example on the freeway at 70 mph, the car all of a sudden goes into limp mode or the trans disengages. At this moment, the car starts coasting and I step on the gas, but obviously no response - the rpms goes up slightly to sometimes to 2 or 3000 rpms, and then the car kicks back into gear. This disengagement period happens for a minute or it can go on for 5, 10 or 40 miles.
I continue to change the transmission oil and use the correct oil (Castrol Transmax Import Multi Vehicle). For each oil change, you only take out 3.5 quarts so after 10 or so trans oil changes that I have done the fluid is still coming out slightly dirty. Despite all the transmission oil changes, the car still seems to disengage.

I have taken the car to Volvo and they did a TCM update which did not help. Also there were no codes in the system. They charged me $250 for this.

I have also taken the vehicle to a transmission shop and they said this was not a transmission issue since at times it drives totally normal (shifts beautifully). Transmission shop said it was a throttle positioning module (ETM) issue because it is drive-by-wire and he said there was a Technical Service Bulletin (All-Data) that described the symptoms like they experienced with my car.

I have also taken the car to an independent automotive shop. Their diagnosis was that the ETM had an ohm reading of 320 ohms, which was way out of spec. The spec they said was 1.5 to 3.5 ohms.

I took the car back to Volvo after the appointments at the transmission shop and independent auto shop. Volvo once again put it on their scope and no codes came up in the computer. The also drove the vehicle and said it was the transmission that was the issue. Their quote for a new trans was $6000.

I have been trying to drive the car as much as possible and recently my approach has been to drive it with a very slow accelaration method, meaning only push on the gas as little as possible as slow as possible to get up to speed. I drove this way for 2 days and the car did not acted up and go into this disengage mode.

Also the disengagement symptoms almost never happen when the car is cold - 95% of the time the car shifts normally and stays in gear when it is cold. Also the disengagement happens more in the city at low speeds versus freeway speeds. One time I drove on the freeway for 20 miles and was driving very aggressively with the gas - coasting to 60 mph, hard accelerate to 70, coasting to 50 hard acceleration to 60 and did this for a good 20 miles and absolutely no disengagement of the transmission occurred during this time. But once I slowed down and got off the freeway, the car acted up and disengaged. 95% of the time when getting off the freeway and coming to a stop and then starting again, the trans disengages.

Any input to these symptoms would be most helpful. Thanks!

 

Update on my 2002 V70.... Volvo replaced my ETM for free and now my car never goes into limp mode! I bought a Autel MS609 OBDII scanner and looked at my Throttle position signal while driving and it flatlined at 12%, which at that same time the car would go into limp mode. I showed the data to Volvo dealer and they searched for codes and found an ETM code, but it didn't pass the death test (ETM signal was only 4.5 degrees from where it should be, Volvo corporate needs ETM to be off by 13 degrees for them to replace the ETM), but they replaced my ETM anyways. Now my car drives wonderfully and the transmission was never the issue. I would like to thank my service manager at the Volvo dealer who went to bat for me against Corporate Volvo.