'02 V70XC: TCM update + valve body questions Topic is solved

[br0dy519]

Just in case anyone didn’t know. Volvo Service 2.0 dictates that any car brought in for any service receives software updates free of charge. So, get an oil change at dealer and ask for updates? I received it for free when I had my seat heater incident.

[vtl]

I did pull the B4 servo out, clean everything in that area well, and polish the pin a bit with diamond lapping paste (it was showing wear and a bit rough in texture) but that doesn't seem to have helped. I know there's a discussion of pin length for this servo, but it doesn't look like this pin has lost more than 0.5mm or so off the tip

0.5mm is the next step.

Also it's not about the pin, it's about trust bearing race on that shaft loosing grip, start spinning and grinding through transmission case. Drum and drum break become non-parallel, so much more B4 servo travel is required to lock the drum.

Next time you pull B4 you can take washer marked 2 out, this will make its reach longer and engagement a bit milder.

[leapdragon]

Okay, so surprising update:

I decided there's no point in playing around with things any farther if I don't even have the latest software installed, so even though I was dubious it would have any effect, I paid for a VIDA 3-day subscription and bought the TCM update. (Vida 3-day: $80 or so, TCM update, $38 or so). I didn't have the original version of the TCM software because stop neutral had been removed sometime since manufacture (this is a late '01/early '02), but I knew that VIDA reported that an upgrade was available, I almost ran it a couple years ago but decided not to bother then.

[BTW @br0dy519 appreciate for the suggestion... basically, if I'm not under warranty, I don't want any other hands anywhere near my car unless absolutely necessary.]

Anyway, THE UPDATE:

The TCM software upgrade... well... fixed everything as far as driveability goes. This is not what I expected. I did the TCM update, I put it into adaptation mode, fully expected adaptation to essentially fail as it had been doing before (I had previously been completely unable to get a flash for 2-3, basically since the flares had started). But instead, things went smoothly.

First 2-3 upshift during adaptation, about 15% throttle, was surprisingly good, just a hint of a flare but it engaged after going maybe 500rpm too far. AND I got the flash yellow. Ran through other throttle levels and indeed the entire sequence, flash, flash, flash, flash, then just drove around. And basically, for now at least, the car shifts almost like new.

This is not what I expected from a software upgrade at all.

Now, the FOLLOW UP QUESTION:

So... what should I do now?

This thing currently has the "wrong" fluid in it (Castrol Transmax Import, which does have 3309 listed, but isn't the real stuff by any stretch) because one of the things I was trying last couple weeks was an "alternate" fluid with slightly different datasheet characteristics. I do have 12 bottles of Toyota Type VI just laying around though. Would you swap back?

New o-rings of variously slightly different sizes and thicknesses have arrived today for the B4 servo piston and cover. Have not touched them yet.

Also, new piston arrives tomorrow for B4 (3 "marks" length instead of 2 "marks" length as on the original) and also there's the washer removal that VTL suggested from the piston assembly that in theory, if I understand things correctly, should behave in something of the same way as replacing the piston (until now, had been planning to try both this weekend and see if one was better than another).

And of course we still have the original valve body on the transmission, which clearly must have some wear at 170k. And who knows how long the brand new GM ones will remain available.

I hate to make any changes because it's just driving so beautifully right now, but also I don't want to neglect things that *ought* to be done for overall longevity of all the bits and pieces (B4 servo, that band, clutches in general, etc.)

I'm inclined to:

- Replace the Castrol fluid with Toyota Type IV just so the "right" stuff is in there (and hope I don't make anything worse again)
- Put the o-rings and slightly longer piston away in a drawer for "sometime in the future"
- Stand down on valve body and just hope that if I ever need one, I can still find one

But I'm open to other suggestions. I'm also trying to decide whether to run the update on my '07 with 230k+ miles. That one also has an update available, but it has always shifted, and continues to shift, like factory new, so I hate to touch it if it's not broken. Thing is, I fully expect that at some point in the not too distant future, all these "software downloaded from Volvo HQ" updates will disappear and no longer be available. Decisions, decisions.

And in the meantime, the TL;DR for posterity is: if you're having 2-3 flares and 3-4 shudders and you can't get them to adapt out, but you don't have the latest TCM software... it can actually make a HUGE difference. I went from "okay, I give up, I'm going to buy a $1k GM valve body and spend a weekend groaning through the replacement" to "this thing is shifting perfectly, I hate to even touch it" via a 1-minute upgrade.

[dikidera]

I would've loved to diff the two softwares

[vtl]

Leave everything as is for now. Replace fluid in the future, as a part of routine maintenance.

I read somewhere that Volvo has almost no adaptation slack in its software. I.e. something goes slightly off, and Volvo TCM can't tolerate that. Perhaps in your software update that strictness was reduced.

What is your TCM software number now? I think I had everything updated, but worth comparing my TCM sw number to yours. My transmission flashes yellow in any gear, no problem, though.

[leapdragon]

@dikidera, I was surprised to see that the firmware size was on the order of 400k, that's white large for an embedded system, unless a portion of this is some sort of loader that executes on Windows in the background. But if it's all TCM, that's a lot of complexity, no?

@vtl I will see if I can dig up a version # in VIDA and get it back to you. If I recall correctly, is that available at the start of the adaptation workflow by clicking on the graphic?

[dikidera]

I have personally, after playing around with modifying ram adaptations previously, that small changes to certain adaptations cause significant shifting differences. If the minimum values are too large, that perhaps can play a role. As well as thresholds. I am unsure what specifically is the target or targets when adapting.

Whilst I can control every single parameter now, shift time, ramp rate and fill time + any pressure i desire through the maps i discovered, the adaptations, still continue to be updated regardless.

The loader can be a vbf , otherwise the tcm software is 512kb.

[vtl]

@vtl I will see if I can dig up a version # in VIDA and get it back to you. If I recall correctly, is that available at the start of the adaptation workflow by clicking on the graphic?

Click on the TCM on Diagnostics tab, it hw and sw numbers are mentioned somewhere there.