Mechanics

QUESTION AUTO TRANS WON'T UPSHIFT PAST 1ST

1994 Isuzu Rodeo

Transmission problem
1994 Isuzu Rodeo Question 6 cyl Four Wheel Drive Automatic 138000 miles

I have a 1994 Rodeo that is stuck in first gear. The gear selector moves through all gears and PRN work fine but D32L all are first only. When I downshift from 2 to L I can feel the transmission hesitate as if it is physically downshifting but the gear is the same. What has been done so far is:
Replace the transmission with a used one. No change.
Clean the Range sensor. No change.
Check the alternator output: 14.29 no load, 14.19 load.

In addition the dash lights for the gear indicator are dead and the Winter switch does not light up on the dash when pushed. The Power switch does as does the 4X4 light.

If I pull connector for the TCM the transmission behavior does not change. My repair book does not have a transmission wiring diagram in it.

ANy suggestions appreciated.
Avatar
Zruhlen
February 4, 2010.



"I've had a problem with hard shifting on-and-off for over a year. It usually happens only in the morning, and is always after the dash light fails to indicate that the truck is in drive. I had the codes read at a dealer last June, and got back a P0705 code. Is this the range sensor malfunction? If so, any recommendations on what needs to be done and where to get it looked at? I had the same problem with my 99 Passport. I was able to remove my range sensor, take it apart and clean the contacts inside. I remember it was quite dirty and greasy inside. I think they used too much dielectric grease in it, but the contacts were definitely dirty so I cleaned them reassembled it and I have never had the problem come back. The unit is located on the side of the transmission (drivers side) just forward of center. It's been well over a year since I fixed it, but if I remember right to remove it there was a small metal shield that pops off. Then I had to remove 2 bolts and 1 nut that holds the shifter arm and unplug the wire harness (the wire harness was a little difficult to unplug due to the tight space) and the unit will just slide right out. You will need a torx driver to take apart the unit. I wiped most of the grease out of mine; I left some of the grease there so things will slide properly and to keep moisture out. Depending on how dirty the contacts are you can clean them with a pencil eraser or a very, very fine sand paper. Don't spend the 90+ dollars for a new one this is a fairly easy fix, once you see the inside you won't think it's worth the price tag! It should take you about 45-60 min to repair."

Tiny
Terrymcd31
Jul 3, 2010.
I have the same problem. Only I have 1st and 2nd with the TCM plugged in. If unplugged I can manual shift 1st, 3rd, 4th. Im having a eletrical shop take a look at it. The guy that wrote in on the top, have you figured your problem out?

Tiny
SeanE564
Aug 28, 2012.