Transmission won't downshift even with TCM unplugged.
06-16-2010, 08:18 AM
#1
Newbie
Thread Starter
Join Date: Jun 2010
Location: Hollywood, Fl
Posts: 1
Likes: 0
Received 0 Likes
on
0 Posts
Year: 1991
Model: Cherokee
Engine: 4.0L
Transmission won't downshift even with TCM unplugged.
Hey guys, first post :\. I've been lurking around these forums for about a week as I just bought a 91 Cherokee with some... 'issues.' Got rid of my JK earlier this year which was a sad moment, but I will admit, I have grown fond of my Cherokee already! Anyways sorry for the brief introduction, I'm sure your ready to hear the problem!
When I bought the vehicle I was told that sometimes the vehicle would stay in neutral when you came to a stop.. I checked the fluid levels and saw the trannie fluid was low so I thought I had a steal. Bought the jeep for $500 and went straight to the parts store and got some trannie fluid (Checked the catalog first, glad I did, takes Merc not ATF +4.) However, on my way home I ended up being stuck in what I thought was neutral. Turned the car off for a few seconds restarted and it shifted (Could start in Drive so either NSS is gone or bypassed.) I made it home having to turn off the jeep at every light. Next day didn't have this issue. After some research I read about unhooking the TCU and since I needed to replace the starter/ignition switch, I left the lower dash with the TCU in the back of my jeep. Shifts like a champ when needed in 1 - 3 - OD. Just no downshift. This went from happening sometimes, to happening every time now. I now turn the car off as I coast to the stop light. After I turn it off, I guess whatever it is that causes it to stay in OD/whatever gear it was in when I turned it off, resets and I can put it in 1st again. I have now noticed that when it is "stuck" in high gear, I can't put it in reverse, it acts as if the TC is in free spin.
For those who don't like the long winded story here is a quick recap
-Jeep will not downshift, even with TCU unplugged.
-Jeep runs rough, rattles etc.
-Won't even go over what it acts like with the TCU plugged in
-I will test TPS today I hope.
-Fluid level is fine, will drop the pan this weekend and change anyways to test solenoids/check for metal shavings.
My question is, is there anything else I should be looking for? Maybe the something in the TC? I plan on getting a multimeter today and testing the TPS, but this wouldn't affect the shifting problem with the tcu unplugged correct? Just let me know if I missed anything to test! Thanks!
When I bought the vehicle I was told that sometimes the vehicle would stay in neutral when you came to a stop.. I checked the fluid levels and saw the trannie fluid was low so I thought I had a steal. Bought the jeep for $500 and went straight to the parts store and got some trannie fluid (Checked the catalog first, glad I did, takes Merc not ATF +4.) However, on my way home I ended up being stuck in what I thought was neutral. Turned the car off for a few seconds restarted and it shifted (Could start in Drive so either NSS is gone or bypassed.) I made it home having to turn off the jeep at every light. Next day didn't have this issue. After some research I read about unhooking the TCU and since I needed to replace the starter/ignition switch, I left the lower dash with the TCU in the back of my jeep. Shifts like a champ when needed in 1 - 3 - OD. Just no downshift. This went from happening sometimes, to happening every time now. I now turn the car off as I coast to the stop light. After I turn it off, I guess whatever it is that causes it to stay in OD/whatever gear it was in when I turned it off, resets and I can put it in 1st again. I have now noticed that when it is "stuck" in high gear, I can't put it in reverse, it acts as if the TC is in free spin.
For those who don't like the long winded story here is a quick recap
-Jeep will not downshift, even with TCU unplugged.
-Jeep runs rough, rattles etc.
-Won't even go over what it acts like with the TCU plugged in
-I will test TPS today I hope.
-Fluid level is fine, will drop the pan this weekend and change anyways to test solenoids/check for metal shavings.
My question is, is there anything else I should be looking for? Maybe the something in the TC? I plan on getting a multimeter today and testing the TPS, but this wouldn't affect the shifting problem with the tcu unplugged correct? Just let me know if I missed anything to test! Thanks!
Thread
Thread Starter
Forum
Replies
Last Post
Psiegrist1
Stock XJ Cherokee Tech. All XJ Non-modified/stock questions go here
34
03-17-2022 02:15 PM
zumer715
Stock XJ Cherokee Tech. All XJ Non-modified/stock questions go here
10
03-29-2019 11:26 AM
NM-XJ
Stock XJ Cherokee Tech. All XJ Non-modified/stock questions go here
18
10-23-2018 04:21 PM
Programbo
Stock XJ Cherokee Tech. All XJ Non-modified/stock questions go here
21
09-26-2015 11:32 AM
Vegas101
Stock Grand Cherokee Tech. All ZJ/WJ/WK Non-modified/stock questions go here!
0
09-04-2015 11:52 PM
Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)