Recently my 97 Sunfire had the speedo quit working, along with it not being able to shift out of 1st gear. Got code P0802. I went through the usual parts replacement for this code, but nothing fixed the problem. As far as I can tell, the gear that drives the speed sensor reluctor wheel is spinning on the shaft in the transmission. I can put the reluctor in and spin it. Anyway, my question is,can this be repaired without pulling the transaxle? I would like to know if someone has had these apart. I have searched for a good diagram of how the VSS is driven but I can't even seem to find a picture that shows the gear on the shaft in the transmission. Any help is appreciated.
What the hell?
First of all, the 3T40 is not electronically controlled. So it should still work just fine without the VSS.
Second, the VSS is a magnetic pickup.... not sure about why you have a reluctor wheel.
Sounds like you have a dead transmission.
i find it amusing that SHOoff has nothing better to do but follow me around & be an unhelpful dick in even cross-forum. - Jon Mick
As far as the reluctor wheel, I used the wrong terminology I guess. You're right, it is a magnetic pickup. The speedometer will sometimes bounce up to 20 mph or so, and when it does, the trans shifts in to 2nd gear, but as soon as it goes back to 0, the trans will downshift in to 1st gear again. I have read about several people that have had the same speedo and shifting problem on the 3T40 because of the VSS being bad, so something is being controlled electronically. I really wouldn't care if the speedometer didn't work but I can't drive this thing in low gear. It would be nice if there was a way to bypass the whole sensor and be able to shift the transmission.
Sorry, in my first post I typoed. The code I got is P0502, not P0802.
P0502 is for low output from the VSS, which sounds consistent with your speedo not working.
Does your shift selector say PRND321 or PRND21? Cuz the 3T40 is not electronically controlled. Sounds to me like you have the 4t40e if it's reacting like that to a missing VSS.
i find it amusing that SHOoff has nothing better to do but follow me around & be an unhelpful dick in even cross-forum. - Jon Mick
No, it's definitely the 3T40 as I have done filter changes in the past. I think I may have figured out why it isn't shifting. The wheel for the speed sensor does not spin when you turn the passenger side wheel. There is a gear on the output shaft that spins the VSS wheel, and that gear appears to spin on the output shaft, which it obviously isn't supposed to. This would explain the P0502 code since it isn't generating a voltage signal to the pickup. It would also explain why the trans isn't shifting, because the governor can't do its job. My problem is I can't find a decent picture of the gear that drives the governor to see if it is replaceable. I was told by a trans rebuilder that the gear is built in to the output shaft, but it looks like a nylon gear similar to what is on the governor. I have rebuilt transmissions before, but not one of these, so I have to go by what I can find online and/or what people are telling me. This is frustrating but at this point I am almost ready to just swap in a different trans, unless I can find out if there is an easier fix. Thanks for your help so far.
Chris
The reluctor for the VSS should be pressed right on to the output side of the differential. But still, the VSS has nothing to do with the shifting. No matter how much you deny it, it's not an electronic transmission and in no way relies on that VSS output for it's shift. So, I'd say you probably have a bad transmission and should change it out.
i find it amusing that SHOoff has nothing better to do but follow me around & be an unhelpful dick in even cross-forum. - Jon Mick
I wasn't saying that the VSS is what shifted the trans in my last post. What I am saying is that the reluctor and governor are the same part in this transmission. I think the part you referred to being pressed on to the differential is the drive gear for the reluctor/governor. I linked a picture of the VSS and reluctor/governor to show you what I mean. The weights on the reluctor function in the same manner as the governor does on a TH350/400 or any other non computer transmissions. The weights hold a check ball against a seat until centrifugal force takes over and the check ball opens. This is when the transmission will shift. Both the speedo problem and the shifting problem started simultaneously, so by all odds they have to be related, and this is the only solution I can see that would cause both problems. Before this the trans worked flawlessly. My main goal here was to find out if this thing was repairable in the car, which obviously it is not, but I did not want to go through changing the trans if I didn't have to. I also like to know why something failed, which in this case I think it was a fluke failure.
Like I said in a previous post, occasionally the speedo would bounce up to and stay at about 20mph and then the trans would shift in to 2nd gear. I think this must be because the gear that is driving the reluctor/governor was catching on occasion and spinning it fast enough to get it to shift. Eventually the speedo would drop back to zero and the trans would downshift back to low gear. If you can think of anything else that would cause both symptoms, I would be interested.
Thanks for your help
Chris
