Contactless TPM replacement? Do they work?

[nortons]

While scanning Ebay for ideas on fixing a persistent, but intermittent ETS dash light problem, I came across a number of ads for a "contactless TPM" replacement. Basically a digital potentiometer replacement for the film in the stock Volvo throttle body. The seller says it does NOT require any additional 'dealer only" downloads as is the case when a throttle body is replaced. The cost of this item runs from about $120 to $150. "Easy, do it yourself" instructions are supplied.
Does anyone out there have any feedback on this? Anyone ever bought one ? Successful?
I have ETS dash light that comes and goes, occasional cruise control won't engage or hold, sometimes at steady 55-65mph feels like torque converter locking/unlocking. Car runs good, otherwise, no hesitation, smooth, steady idle speed. Recent timing belt/tensioners/water pump replacement, (at 106,000 miles, with no running problems, all timing marks correct), has inexplicably raised indicated avg. mpg. from 17.2 to 19+ mpg. (dragging tensioners?)
I have replaced the brake switch and readjusted it a number of times resulting in light going off temporarily.
Lots of reading here indicates to me that throttle body film MAY be problem. This digital "contactless" replacement may be a $150 vs $500 option.
Anyone have experience with these?

[JRL]

Sacer?
Go to www.matthewsvolvosite.com

There are several there who have installed the part.
Personally I would spend the extra bucks and buy a XeMODex built ETM which is guaranteed but if done properly it's the same thing just without the expertise with the install.

...and stop being cheap, get the stored codes read at Volvo or buy yourself a VIDA-DICE. All you may need is a NEW brake switch sensor

[nortons]

Jeez, JRL! Not being "cheap", just trying to do what I can afford! $500 here, $500 there, every couple of weeks; keeping this thing running is costing me as much as payments for a new "transportation unit". Sorry I'm apparently not sufficiently wealthy enough to be a Volvo owner anymore.
I thought the purpose of this forum was to share tips, ideas, experience and knowledge to help owners maintain and repair their own cars and maybe save a few bucks in the bargain. Not be "dissed" for being "cheap".
I've owned scores of cars, trucks, bikes, etc in my nearly 50 years of driving; I've done 99% of all the work on them too, (don't have an alignment rack!). I'm just trying to understand, diagnose and correctly repair this thing.
I'm sorry I have apparently offended you; so I guess I should just turn off the light, shine it up and palm it off on somebody else.
Sorry, I was just looking for a little help. Won't be back.

[JRL]

You need to read the stored codes
I don't see where that would offend you/me. You've complained about this XC since day 1 but there are certain things that can only be done one way (unless you have a VIDA reader), it's as simple as that.
However, you already know this and yes, I know these cars nickel and dime you to death.

"Hunting and pecking your way through these is not the way to do it".
Seriously go to Matthews. I can't believe that certain owners replace this, replace that, back to replacing this again and still have a problem when either reading the stored code(s) or just asking people what to do before they go through this would make life much easier for them