Fix for code 84 TORS and Reverse

[Mooseman]

Yesterday, the MP threw me a code 84 for TORS activation, and that was just on starting the engine without touching the throttle. So I get into the repair manual and do the following:
- check throttle cable free play (fine)
- check throttle switch operation (good)
- check the throttle position sensor adjustment

On the TPS, I adjusted it as the manual says by measuring the voltage of the yellow and black/blue wires to be between 0.63v and 0.73v. Still getting code 84 on startup. So I pulled the TPS and checked the specs for max specified of 4-6kΩ on blue and black/blue wires. So TPS is good and adjusted to spec.

I then looked in the diagnostic mode for the TPS reading, which, with throttle closed, is supposed to be between 15 and 18. It was showing 16, so within spec. Reading how TORS works, it activates if it thinks the throttle is being opened without the throttle switch being "on". Figured I'd try adjusting it to the lowest possible 15. Wasn't easy because when I would tighten the screw, it would alter the TPS. Finally got it to 15 and code 84 was gone!

Now another interesting thing, took it for a ride today after the fix and I noticed that my green D light did not flash anymore. I used to be able to make it flash each time I decelerated. No more! I was also hoping that it also would have fixed the "push the reverse button and nothing happens" problem but alas, that persists. However, it seems to work more consistently if I turn the key directly to Start instead of turning it to Run first and then Start. It seems to be some sort of bypass according to the reverse update bulletin.

 

[YukonMP]

I've been hesitant to post anything about my reverse because I'm uncertain what I have going on ... but it is good. When I first start my sled up it is jacked up and I have pounded on the tunnel to loosen the ice. I immediately hit reverse and it shifts nine out of ten times. I spin the track in reverse and immediately shift to forward and again it almost always works. Two mornings in a row I looked at my tach and I still had over 2700 rpm. This is the drill everyday. Basically no reverse issue but when there is I can always get it to shift by blipping the throttle. That works whether it is flashing or doing nothing. I had a hunch that it was something to do with the TPS.

Nights when the sled is in the shop it is not jacked up but the first thing I do is back it out. This morning it took reverse while the red light was still on.

In addition to the above I have noticed that the sled will dip to a very low idle (1000rpm) and then recover to normal. Occassionally it is even lower and stalls. This only happens when I am creeping the sled up to a fishing hole. I thought this might be a TPS issue also.

So that is my bit on our reverse gremlins. No doubt we will get to the bottom of this one day.

 

[Mooseman]

I also just put in a new belt, an 8GS, and when it does work, has been harder to shift. I have a couple of 8GK's so I might try those out to see if it improves.

Thinking aloud here, what if I put the TPS lower than 15? I might give it a try just to see if this could clear up the "nothing happens". I know if I touch the throttle at all, nothing happens when I hit the button, which would be a safety thing built in. I also checked in diagnostic mode that the speedo sensor isn't throwing any ghost pulses.

The shifting difficulties I can deal with but the nothing happens scenario is just frustrating as I have to restart the engine to get it to work.

 

[Mooseman]

In the middle of a ride right now. I adjusted the TPS to 14 and it didn't make a difference except that the motor feels peppier off idle. The turn the key straight to start trick only works for a while as later in the ride, it did nothing and had to restart. The 8GK belt made a difference at the beginning but once it gets hot, it's worse to shift into and out of reverse. oh, the flashing D is back.

Apart from the fixing the code 84, I give up on trying to fix the reverse.

 

[Mooseman]

I just can't shake this damned code 84. On cold start, it comes on even before I touch the throttle. Shutting it down and restarting usually clears it up. I tried bypassing the TORS throttle switch and it was actually worse.

So after I finished my ride today, I went into diagnostic mode and it goes from 14 to 102 (specs are 15~18 to 100) however, playing with the throttle, it sometimes goes down to 13, then 14. So I wonder if this is causing my code 84?

So my TPS is possibly faulty but at $261CAD on a hunch, I would rather try and save it or keep trying to adjust it. Since it is basically a variable resistor, anyone think it would be bad to use contact cleaner in it?

I did find it a bit cheaper on fleabay for $155US incl. shipping and on another site (megazip.net) that has it for $128US incl. shipping from a warehouse in Japan.

 

[Mooseman]

OK, hopefully this will be my last post on this.

So was still getting code 84 every now and then while riding. This was its last chance.

I take the TPS out and try to get some contact cleaner in there. I think it is sealed completely since it didn't seem to get in at all. Work it anyway just in case. Put it back in and adjust it using the diagnostic mode. Try to adjust it as per spec between 15-18 and it kept changing when I moved the throttle. I eventually set it to 17 and it doesn't move from there. Played with the throttle lots and it always came back to 17 consistently. I think if it's just borderline between two, it will change.

So take it on a long ride. It threw a code 84 right at the beginning once after a full throttle pull. It might have just been relearning its new throttle position because it behaved the rest of the ride. On top of that, reverse worked perfectly! Not once did it refuse to try to shift. Hallelujah! This has been plaguing me for years! And I used an older belt that was still within spec but sat right flush with the sheaves so it shifted a lot easier in and out of reverse.

So for anybody reading this for Venture Lite/MP or Phazers that have the "push the reverse button and nothing happens", check the throttle angle in diagnostic mode, play with the throttle a lot and see that it consistently comes back to the same number always. And to make your life a little easier, drill a hole just above the belt guard to access the TPS screw (learned that one from another member).

 

[Ronald]

OK, hopefully this will be my last post on this.

So was still getting code 84 every now and then while riding. This was its last chance.

I take the TPS out and try to get some contact cleaner in there. I think it is sealed completely since it didn't seem to get in at all. Work it anyway just in case. Put it back in and adjust it using the diagnostic mode. Try to adjust it as per spec between 15-18 and it kept changing when I moved the throttle. I eventually set it to 17 and it doesn't move from there. Played with the throttle lots and it always came back to 17 consistently. I think if it's just borderline between two, it will change.

So take it on a long ride. It threw a code 84 right at the beginning once after a full throttle pull. It might have just been relearning its new throttle position because it behaved the rest of the ride. On top of that, reverse worked perfectly! Not once did it refuse to try to shift. Hallelujah! This has been plaguing me for years! And I used an older belt that was still within spec but sat right flush with the sheaves so it shifted a lot easier in and out of reverse.

So for anybody reading this for Venture Lite/MP or Phazers that have the "push the reverse button and nothing happens", check the throttle angle in diagnostic mode, play with the throttle a lot and see that it consistently comes back to the same number always. And to make your life a little easier, drill a hole just above the belt guard to access the TPS screw (learned that one from another member).

My TPS maxes at 106 full open. I've adjusted it several times to try to get it in the right range but then it's way too low (like 6%) at closed position. Last year I brought it down to 10% and that seemed to help with reverse issues, but not so much anymore and the bottom end seemed to suffer. As I'm mostly on ungroomed trails for fishing, this kind of sucked. Does this mean my throttle cable is strectched or do I need a new TPS? Like someone mentioned before, the reverse works if I start it right away, without letting it do its start up checks. I also get 84 and 15 codes sporadically. Nowadays it read anywhere from 15 to 20 closed throttle.

 

[Mooseman]

I think the high range that is going beyond 100 is caused by the throttle body itself that may overextend slightly beyond where it should stop. Mine maxed at 105.

Oh, and before I parked it for another issue, the reverse was still being finicky doing nothing when pushing the button but not as often. And going straight to start didn't work for me except for the first use of reverse and would later do it again. I think the ECU is programmed too tight on when to allow reverse to work or not.