1999 Auto No reverse, shifting problem
 

I just received a 1999 Hyundai Accent as a hand me down. Story is that the trans just "went out". After that it was parked.
The fluid was low. I added some to top it off. Checked hot in neutral. The car will not go into reverse. It goes into drive just fine. While driving down the road it would not shift out of first unless I let off the pedal. If I did that, when I reapplied the gas it would then shift but it was more like a slam into second.
As I mentioned I had to add fluid cause it was low but the fluid was not burnt. It was worn out though, brownish.
I have done some research and this problem could be caused by some kind of faulty sensors in the trans. I have found out that these are easy to change but I cannot seem to determine how easy or even what these sensors are. Car only has 75000 very easy miles on it. Any info on this would be greatly appreciated! Thanks.

No, I think the original diagnosis is correct. Dead trans. I highly doubt replacing sensors will fix the problem. Take it to a transmission specialist.

So I dropped the pan. No indication of anything wrong. In fact, besides the fluid being worn out everything looks great. No shavings or chunks of metal or anything.
I'm debating weather I should just try putting a filter in it and new fluid or dropping the valve body and checking things out further.

I replaced the fluid and filter. After all was back together, I took it for a ride. To be specific, it has no second gear, no overdrive and no reverse. When it tries to shift to overdrive it simply revs out.
I am not convinced the trans is toast. Theres just no evidence of that. No slippage at all. Id hate do dump money into a rebuild and find out that nothing has changed.
Someone has to know, someone must have had this problem before. Thanks.

So its been sitting for about two weeks or so. I decided I'm gonna drive it. So I drove to walmart and back. No indication of reverse what so ever. I would put it in 1 then after rpms got up to 4k I would let off the pedal and put it in drive. I could then feel it go to third. I would apply the pedal and go along.


I noticed If I put it in 2, it would seem to still start off in first and not shift to second. So I began doing that. What eventually happened is if I let off the pedal while the shifter was in 2, it would shift to second gear. If I applied the throttle it would drive in second gear for (give or take) a football fields length then seem to "neutral" out. Letting off the pedal again would yield the same results.


I am beginning the think the issue is completely valve body related. What I cannot determine is where these rumored sensors are, or part numbers for them, or even the name of them! Info on this car is not easy to get it seems.


Question: does anyone know the part numbers for these rumored sensors that are on top of the valve body? Thanks!

Sounds like the transmission computer has put the transmission into limp home mode. I had the same problem on my 1999 Accent. Is the MIL on? Have you plugged in an obd2 scanner?

There's a speed sensor bolted into the transmission bell-housing that tells the transmission computer the input speed and output speed of the transmission. If that craps out, the computer resorts to limp home mode, with behavior similar to what you described. The transmission computer throws a code for the sensor, and a second code to indicate it has requested the engine computer light the MIL.

Remove the battery and the battery tray to gain easy access to the sensor. That area sees a lot of vibration; check the wiring harness as well. On my car, one of the wires in the harness broke off right at the connector (inconveniently on the car side of the plug, not the sensor side). I cut off the connectors and spliced the existing sensor directly to the car's wiring harness, reinstalled the battery and wiped the codes using the obd2 scanner.

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