2001 v70 T (p80 ETM problem ) Is this the ETM issue that I've read so much about on this board?

[Chris616]

Our 2001 V70 T5 (~140K km, 87K miles) that has given stellar service since we bought it new has started to produce a mild surging when driving at constant speed (not when idling, or accelerating). There are no other indications of a problem. To do some diagnostic work I finally had a reason to buy a scanner tool. On a recent test drive that collected 7000 data points (~45 minutes of driving), the two ETM potentiometers read within 10% of each other 88% of the time. In 5% of the frames potentiometer #2 read higher by 70-80 degrees, often showing what looks like the maximum value of 108.19°. My passenger made note of when we perceived the surging happening and I could always correlate that to when the two potentiometers were highly divergent, but on reviewing the data there were many times when the two potentiometers were highly divergent and we did not feel any surging. Hmmm…maybe the surging was happening but road surface imperfections masked us feeling them. The scanner showed no other engine or transmission related codes.

It seems to me that the ETM is the likely source of the driveability issue and that it will only get worse over time. Do others concur?

I’ve researched this but have been unable to find the answer. For the Volvo ETM with two potentiometers, how does the computer algorithm handle highly divergent data from the two potentiometers? Average them? Disregard one that it judges is in error based on other parameters (like the 108° value while the accelerator pedal position is inconsistent with that)?

Most of the offered solutions on the board are quite old, so I’m unclear as the best fix available now, so would appreciate advice from those more knowledgeable. A replacement from XeMODeX, or a 2015+ used ETM from a scrapyard or a new unit from Volvo? Thank you.

[volvolugnut]

I believe you have a problem with your ETM. XeModex website has a flow chart to troubleshoot ETM problems. I believe the best and cheapest solution is still XeMoDex replacement.
Others will likely post here soon.
volvolugnut

[abscate]

Greetings, Chris

I would look for the late ETM on eBay , they come up often at about $150 or so. If you can match it from a turbo car , which knowledgeable sellers will note, it should bolt on and play. There seem to be a bunch of PRC ebayers selling these in qty, thst never made sense to me. I would buy one picked from a junkyard in the US of known history , with a well rated seller

The sure fire thing is to go the Xmodex route but that’s more expensive, like $600 plus$300 software transfer. . I believe they lifetime warranty these to the original purchaser.


Your symptoms fit ETM mismatch exactly. You probably have 10,000 miles before limp mode, where your car will run about 2000 rpm/30 mph to get you home , so time to look for those options!

[scot850]

Try calling Chapman Motors on Vancouver Island and see if they have a good one available. They are not cheap but I have never had a bad part from them.

Neil.

[firstv70volvo]

Not cheap but a recent (20 2021) Volvo rebuild.

https://www.ebay.com/itm/181840976917?f ... SwT~Zin9QO