does ETM failure have many different symptoms?

[carboncow]

2001 V70 T5 with 120,000 miles. Newer to me as the 2nd owner. Wife who is expecting our first born drives the car, so we want it safe and secure. I'm a great DIY'er who's been around the block with Saabs, VWs and BMWs...but first Volvo, love the car but...

We've noticed some pulsing at highway speeds and thought it may be the cruise control and/or AC turning on and off. Now that it's stalled on her twice (stop sign and driveway) I internet search has me thinking the common ETM failure looming. No limp home (yet), CELs or codes from OBD2 scan.

Looking at Mr. Wilson's site I see that original units had a white label, while replaced have yellow...

Questions:

1. Are the replacements prone to fail eventually too...as they are the same flawed design?
2. Should I check the unit based on info from Wilson's site (for wear) or am I off base with my theory since there is no limp home, CELs or codes.
3. Should I just be checking the MAF/TB for a good cleaning?
4. What else is known to cause low speeds stalls and produce no codes?
5. Does the dealer have a national database of records to tell me when this unit was replaced (50,000 vs 110,000 miles) to give me an idea of life of this unit?

Thanks in advance for constructive comments.

-carboncow

[Rob3]

The Dealer told me that Volvo had upgraded the ETM, so that can't be my problem.

Xemodex replacement ETM cured it. (So much for the Dealer's input.)

My ETM failure was not at idle. It was at medium and heavy throttle. It would lose power, downshift, regain power unexpectedly. Idle was always fine.

The ETS Light did not come On until the following day when the engine was restarted. Driving for hours the day before (with the symptoms happening if I steped into it too much) the ETS Light did not come On. My understanding is that there needs to be several failures stored before the Light comes On, and that a few "good starts" will turn it back Off again.

When my ETM was acting up, I could pull No Codes, and the ETS Light was not On. (I carry a code reader in the back of my Car.)

I don't think cleaning is going to help problems which are not happening at idle. Additionally, if the ETM is bad, cleaning won't make it "good" again.

Maybe you could slowly rev the Engine in the driveway and see if there's a position where it malfunctions? If it's good on either side of this position, I'd surely suspect the ETM. `Might try this on a Freeway, too. Downshift to 3rd, if need be, to get the RPM's high enough without speeding.

Sorry, but I'm out of ideas at this point. Good Luck.

[carboncow]

So "the dealer" told you that the replacement ETMs should fix the concern? (thus yellow labels are better or just simply identical replacements?).

We have not had a stall or code since I wrote my concerns over a month and half ago! I've actually started to think the pulsing could be the transmission lashing some too as it appears to lash at low speed pulling away from a light. I'm going to do the fluid and plug soon and we'll see if my concern is there.

I'm going to review your ideas for finding the concern or sweep spot at rpm or load.

thanks for input.