Defeating the torque limit request on the Volvo 850 Turbo

Bondo1 · Post by **Bondo1** » 27 Nov 2012, 23:26

That sucks to hear that didn't work for you either Matt. I had in anticipation of this mod working crimped male and female connectors on the ends so I could plug and unplug as I choose, but now I'm just gonna plug it back together and and call it good. Maybe it's a good thing it didn't work.......I'm sure it's gotta be hell on the tranny. Are you gonna try slicing any of the several other wires that have been talked about in these post? If you get it to work I still might have to try it just to see what the difference feels like in he seat.

Post by **matthew1** » 28 Nov 2012, 11:06

I'm going to wait for Jimmy. If he doesn't have any ideas, I'll probably solder the wires back together and chalk it up as a worthy attempt at making my 850 faster for free. Nothing ventured, nothing gained

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Post by **boosted5cyl** » 29 Nov 2012, 23:16

northernlights wrote:I just came into possession of a 1996 vintage service manual for the AW50-42LE. There is an interesting twist to the torque limit request issue. If I am reading the literature correctly, it looks like one must supply battery voltage (e.g. 12 VDC) to the ECM connector B42 aka the green/yellow wire in order to NOT have the torque limit request. This appears to be what the TCM sends the ECM during normal operation when no boost limit request is in place.

You don't happen to have this manual fully scanned in by any chance?

Post by **northernlights** » 01 Dec 2012, 19:04

Unfortunately, a hard copy only. My scanning capabilities are presently one page at a time - that's why everything I post is piecemeal.

Post by **jimmy57** » 02 Dec 2012, 01:42

I am working in Canada for two weeks. When I get back I can put my hands on a 98 C70 conv and perform what I've done before to defeat boost control based torque reduction. If I can get my hands on a up to 98 turbo P80 while I'm in CAN I'll answer sooner

t5steve · Post by **t5steve** » 02 Dec 2012, 14:10

i'm watching this thread with interest..............

Post by **matthew1** » 02 Dec 2012, 14:21

So am I. Oh wait, I'm part of this thread.

NL, Jimmy, and anyone else invested in this topic, let me know if I can do anything to help. NL, I'm still uncertain about the 12v ECU signal. I'll do it if even one user with credible history says it's probably OK. I don't want to fry an ECU, but they do seem to be fairly hardened/robust electronic devices. In addition, even if there's a chance of losing an ECU, it's something I don't mind because it's --quite literally -- my job to flush out Volvo troubleshooting and performance applications.

Post by **northernlights** » 02 Dec 2012, 20:17

Your hesitation is completely understandable. Personally, I'd love to have a breakout box to use for testing these things prior to making modifications that could damage equipment. Barring one of those appearing or being fabricated, all I can personally do is report what I find in the factory books, or make predictions from first-hand experience. Unfortunately, most of my Volvo specific experience is with the 240's. So, as I have many more 850 Volvo manuals than 850 Volvo experience, I'm stuck relying on the former more than the latter.

anglveyes · Post by **anglveyes** » 09 Dec 2012, 20:15

i also tried the green and yellow wire but did not notice any difference. i was tempted to try the leading it to the battery but cant afford my car to go down, let alone the ecu. but hopefully we can figure this out.

t5steve · Post by **t5steve** » 05 Jan 2013, 10:35

is there any updates .................has anybody made this mod work................watching with interest

Defeating the torque limit request on the Volvo 850 Turbo

Re: Defeating the torque limit request on the Volvo 850 Turb