Trans solonoid question
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From: Mitchell Co. NC.
Year: 1997
Model: Cherokee
Engine: big 6
My 97 model cherokee has a bad solonoid for 2nd gear meaning it skips that gear completely at all times. I also have an 88 model parts jeep. My question is can i use a solonoid from my 88 in my 97? I know the trannys have diff wiring so i cant switch the 2 out but can anyone tell me if this part of the guts will swap out.
Thanks, KSB
Thanks, KSB
Thread Starter
Seasoned Member
Joined: Sep 2010
Posts: 427
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From: Mitchell Co. NC.
Year: 1997
Model: Cherokee
Engine: big 6
And no i didnt search not one bit for this answer, thats all i ever do and im sick with the *****s of doing searches when i can just ask. Its just a question anyway so i dont wanna hear any search whining, just advice please. Thanks again in advance lol
Caracticus Potts The Mod
Joined: Jul 2009
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From: Hainsville, NJ
Model: Grand Cherokee
improvements as the years go by dictates component variances that prevent swapping between such a large time span.......that being said..LOL completely different valve body assembly
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From: Nor-Cal Coast
Year: 90,84
Model: Cherokee
Engine: 4.0,2.5
Originally Posted by DFlintstone
Somewhere I saw a deal, (I don't want to mention names and be wrong), Ok..was 5-90 or Laredo, You can use an analogue meter with a needle to watch for a smooth voltage sweep from the (pot), (potentiometer), in the TPS.
\Salad, (cananian don't you know)
Yep. If you backprobe the TPS between the sensor ground and the signal wire you should see close to 0V at closed and a SMOOTH sweep up to 4.5V all the way open. Anything other than this and it's shot. To test it while it's not running you could get an analog meter in resistance mode and perform the same test. Resistance between the signal and ground should increase smoothly as the throttle opens, or decrease between the signal and +5V feed.
Not knowing much about TCU signals to the solenoids, I thought I'd toss that out. Guess your PCM signals the TCU, partly with TPS input....but only one gear. ?
Somewhere I saw a deal, (I don't want to mention names and be wrong), Ok..was 5-90 or Laredo, You can use an analogue meter with a needle to watch for a smooth voltage sweep from the (pot), (potentiometer), in the TPS.
\Salad, (cananian don't you know)
Yep. If you backprobe the TPS between the sensor ground and the signal wire you should see close to 0V at closed and a SMOOTH sweep up to 4.5V all the way open. Anything other than this and it's shot. To test it while it's not running you could get an analog meter in resistance mode and perform the same test. Resistance between the signal and ground should increase smoothly as the throttle opens, or decrease between the signal and +5V feed.
Not knowing much about TCU signals to the solenoids, I thought I'd toss that out. Guess your PCM signals the TCU, partly with TPS input....but only one gear. ?
Last edited by DFlintstone; Oct 11, 2012 at 10:02 PM.
1st gear - solenoid 1 ON, solenoid 2 OFF
2nd gear - solenoid 1 ON, solenoid 2 ON
3rd gear - solenoid 1 OFF, solenoid 2 ON
4th gear - solenoid 1 OFF, solenoid 2 OFF
Lockup - Solenoid 3
So.. if solenoid 1 were bad, 1st and second gear would have problems. If solenoid 2 were bad, 2nd and 3'rd would have problems.
I can't figure which would cause a second gear-only problem. Seems more of a control/TCU problem? Or perhaps a voltage/ground problem that isn't allowing BOTH solenoids to operate simultaneously?
2nd gear - solenoid 1 ON, solenoid 2 ON
3rd gear - solenoid 1 OFF, solenoid 2 ON
4th gear - solenoid 1 OFF, solenoid 2 OFF
Lockup - Solenoid 3
So.. if solenoid 1 were bad, 1st and second gear would have problems. If solenoid 2 were bad, 2nd and 3'rd would have problems.
I can't figure which would cause a second gear-only problem. Seems more of a control/TCU problem? Or perhaps a voltage/ground problem that isn't allowing BOTH solenoids to operate simultaneously?
Last edited by Radi; Oct 12, 2012 at 12:27 AM.
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Thread Starter
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From: Mitchell Co. NC.
Year: 1997
Model: Cherokee
Engine: big 6
Well i figured there would be improvements but i was hoping it was one of the things that was left alone. But thanks for the thurough explination lol
Thread Starter
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From: Mitchell Co. NC.
Year: 1997
Model: Cherokee
Engine: big 6
The '98 solenoid is physically smaller and the connector points in opposite direction than the '88, but they appear to be interchangeable.
Pictures here:
http://www.naxja.org/forum/showthrea...ight=solenoids
Pictures here:
http://www.naxja.org/forum/showthrea...ight=solenoids
Thread Starter
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From: Mitchell Co. NC.
Year: 1997
Model: Cherokee
Engine: big 6
Alsoused trannys go for roughly the same price as a set of solonoids. Which is why i over looked fixing the trans i have in the first place. Just back ground info
See im in a rough spot cause 97 had a 3 pin wiring harness on the trans and the newer models had a 5 pin connector so i cant just swap in another trans from a newer year. Id been waiting on another 97 but looking for just 1 year model is a pain. I know the newer solonoids will work but i have an 88 model on hand for parts. I may yank them out and just size them up with some online pics so i dont have to waste any fluid.
You could try the older solenoid, if it fits- then it does. If it doesn't you are no worse off.
I'm a bit more curious as to why you only have 2'nd gear problems when each solenoid directly affects two forward gears. Have you measured the coil resistance? 8-11 ohms? If they are way off I wonder if the TCU can't supply enough current to pull both solenoids in (second gear) at once. Or if the power connection/ground is bad, causing the same issue.
Thread Starter
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From: Mitchell Co. NC.
Year: 1997
Model: Cherokee
Engine: big 6
My jeep is a 1997 model and the part in question is a solonoid from an 88 model i have laying around. And there are 3 solonoids so how does each control 2? I was under the impression that solonoid 2 controls only second gear. I think the 3rd one controls 3rd and OD. Its late so im kinda scatter brained but theres a post that says which one does what somewhere (i dont have it on hand at the moment) but either way iknow for sure that mine is not working. I looked up its code and it says shes hurt and a mechanic suggested swapping it before i changed the tranny. He also said he didnt think it was a faulty tcu either
CF Veteran
Joined: Aug 2011
Posts: 10,489
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From: Nor-Cal Coast
Year: 90,84
Model: Cherokee
Engine: 4.0,2.5
It's late, I'm tired. If you can get info from Radi.....you lucked out. Best to all..(I saved that earlier in my "data bank") I don't get it...yet, but thanks Chuck!
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From: Mitchell Co. NC.
Year: 1997
Model: Cherokee
Engine: big 6
I like your trial and error idea lol. This issue really sucks on mtn rds. It doesnt downshift to 2nd when going up a hill, instead it lugs up it. Also trying to pass in the 45 mph range sucks cause again, it only lugs 3rd instead pf downshifting to second. When going downhill if i pull it down in 1-2 it only gives me 1st which is too low even for holding back. And worst off all my roomie has a 4cyl auto 96 yota taco ext cab with a 3" lift and 31s (slow and weak in other words) anyways from time to time we end up catching redlights usuay on the way home from the woods or work and we both have matt it of course to see who rules the roost and ill get him at first but then instead of 2nd i go to 3rd and then im lugging again as hes driving away giggling like a school girl i imagine.. It sucks lol. And yes i know it not exactly legal but as slow as our rides are anyway it doesnt even look like racing lol. And god knows how bad this mess is prob effecting my fuel mileage. If i take it easy and drive like a normal human being you can hardly tell its even doing it but when i need that extra kick or hold back im at a loss


