guzzinerd

I bought my Sport new and after 175k miles is giving me symptoms of failing solenoids:

• Takes a few seconds for reverse to engage when cold
• Can't decide what gear it wants to be in on some hills (usually at just above 2k rpm)

The transmission fluid is fresh and topped off, new filter. I change it myself and it's always come out red never black/burnt.

Main question is this... CAN the solenoids start to fail without throwing a code? My engine light is not on so there are no codes to read. I don't want to change them out for nothing.

Thanks

IJM

First, and not to insult your intelligence, did you check your trans fluid level properly? As in warmed up after a decent drive with the engine running and trans in neutral? If so, I recommend you check the resistance of your solenoids. Start by testing the entire circuit before you even think of dropping the pan. More info here: https://www.cherokeeforum.com/f2/doe...-legit-195669/

guzzinerd

No worries. Yes, always I check it always when hot and in neutral. I'll read the link.

Thanks
Alex

4.3L XJ

Slow to engage in reverse is common on many transmissions. As far as hunting for gears, you may need to adjust your throttle cable kick down

awg

unrelated to solenoids , there is a drainback valve and spring

test the resistance at the plug in engine bay...solenoids usually either work or not, and the symptoms of failure are not what you describe

lawsoncl

Although they can fail without producing codes, the solenoids don't affect reverse. Still wouldn't hurt to measure their resistance if you're in doubt. X2 on checking the throttle to trans cable, as it controls the hydraulic pressure and hence shift firmness. Too loose and it won't even shift.

97/01XJ

I am jumping on here in hopes of helping someone and getting help seeing as this is a newer thread and I didn't want to create a new one.

97XJ that seems to keep eating solenoids (pin 13 at TCM for B solenoid). Replaced all three solenoids about 2 years ago with 310000 miles with Ebay cheapos due to the B solenoid failing not allowing downshift to first (shifts as should manually). Checked all solenoids prior to removal, the B solenoid and lockup solenoids were well out of spec and checked the new ones prior to buttoning up the pan to make sure it was good.

Good to go until about April of 2021 with 325000 and the same issue of not starting off in, or down shifting to first. This seemed to have happened right after descending from the Sequoias and conducting manual downshifting and enjoying the lovely harsh 2/1 downshift at 27mph repeatedly. Tested coils at engine bay connector, B solenoid out of spec again. Dropped the pan again, got junk yard solenoids out of an appropriate 4runner with all coils testing good. Installed the 4runner solenoids, worked as normally should for a week or two. Then my wife hesitantly informed me that it's not working again as she waited for the mushroom cloud to clear our entire neighborhood.

Now I am back to out of spec readings at 1-ish ohm on B/pin 13 at TCM, other coils are great at 15 ohms. I am lucky enough to have a junkyard TCM, but of course that doesn't help my issue. I have followed various thread troubleshooting guides and am failing at achieving success and getting pretty frustrated.

I am looking for help as to why the red beauty is eating solenoids. I just removed and cleaned the NSS due to intermittent reverse lights and have done about a million other things that I can list if anything helps. Checked the TPS and adjusted the cable just for fun. I would try adding tue extra fluid trick, but figure if the coil is at 1 ohm, it'll be useless. I don't mind dropping the pan again (cleanest 325000 AW4 fluid in the world), but I want to solve the issue.

Please help!

awg

some comments

(with failed no 2 and 3 solenoids)..I have just removed used ones from a spare trans to fit to mine asap

this is the 2nd time, and I found that the No2 and 3 were failed or removed from other AW4

so it seems like this is a common issue

however, I cannot think of a logical way the fault can be other than old, heat affected solenoids, or low quality aftermarkets

The TCM send 12V thru ~12-15 Ohms, so an over current can only happen if the coil goes low resistance, (mine fail high)

I can only suggest you replace the failed solenoid with OEM quality new

In my case, the TC solenoids are in spec, but dont work (they do make a clicking sound if they work)

It is frustrating

going to add a magnafine auto trans filter to my cooler return line, I suspect they may get jammed

97/01XJ

First poster... I hope I have not hijacked your post...

I wanted to followup so maybe it'll help someone. Dropped the pan, lo and behold, all solenoids tested perfect. Checked continuity from TCM connection #11, 12, 13 to the 6 pin plug connection that uses 5 pins near trans dipstick handle... all great at 0.2 ohms.

Checked from 6 pin connector to individual solenoid connections inside trans... perfect. Sprayed electronics cleaner in both sides of plug for good measure, reconnected plug at dipstick handle.

Checked from TCM plug to solenoid connections in trans... perfect at 0.3 ohms.

Noted that spade connections at solenoids seemed a little loose... of course broke the fancy brittle connection housings that I had took so much care to preserve and replace on prior endeavors. Got angry and said to heck with them. Closed each of the female spade connectors to make a tighter connection.

Noticed some missing loom chunks on drivers side of trans. Thoroughly checked wire's insulation and put new loom over the external wires. Checked resistance readings one more time, all in the 13.5 neighborhood! Hooray! Actuated solenoids from TCM plug, A and B gave loud audible clicks... lock up not so much. Decided to stick with the solenoids that were present. Closed up the pan. Filled er up.

Test drive... hooray! First is there as it should be... and second, third, and forth too! Shift points are completely different now (need a little more rpm and has a more noticeable shift). Took it down the interstate... wondering if the torque converter is locking up as rpm seemed a bit high.

Brought it back, Checked codes... jeesh, P700 remains and now P0122 is there.

Good grief. Spent five hours screwing around with the 122 code. Checked tps in all known manners except just changing it. Had the battery pos and neg disconnected and hooked together to try and start fresh. Hooked it all up after the extended measuring, checking, etc... P0700 and P0122 still present. Also did the cable adjust just for fun as well.

At least 1st through 4th are here now, but what am I doing wrong??? Why did this tps low volt code show out of nowhere now?

Back probe ground switch off 000.0v
Back probe ground switch on 9.5mv
Back probe center pin switch on, idle posn 0.878v
Back probe center pin switch on, WOT 3.975v
Back probe supply, key off 64.6mv
Back probe supply, key on 5.10v

Any insight would be greatly appreciated!

OldTires

3 weeks ago, on an unusually warm day for Spring, when the temps got into the 80s, I had to drive into the city in heavy traffic. After about 45 minutes of driving, the shifting went to hell. I had to manually shift through the gears from a stop, instead of being on D. Once home, I read that the TPS is probably the issue, at the heat in the engine bay degrades them. Not having my tester with me, and not wanting to buy another and spend more money, I swapped in the OE TPS that I had in my parts box from 5 years ago when I replaced all the sensors on the throttle body. Right off the bat, shifting improved, and I could take off from 1st while in D. But now 2nd was missing and 3rd was delayed.

So I bought a new TPS from the dealer to replace the old OE sensor that was working but was probably the original. Installed it and the shifting still skipped 2nd. So I tested the solenoids from the harness, and 2 of them were out of range by a lot. Dropped the pan again (had dropped it in December but decided not to mess with solenoids) and took out the old solenoids. Tested them again while they were out and all 3 test fine. Wut? I still didn't trust them, so I installed the new solenoids anyway. The new solenoids, installed, tested perfect from the harness pins. While the old solenoids did not test right from the harness. And the Jeep now shifts again with no issues so far.

My thinking is the TPS and solenoids were failing but the cold weather didn't stress them enough for me to notice. Then when confronted with a hot day, driving in city traffic, they gave up, especially the TPS. You are seeing a lot of solenoid threads now too, which probably means the OE solenoids are reaching their end of life.

97/01XJ

Well... the grace of God fixed the Red Beauty. After extensive TPS, TCM, and other trouble shooting... the codes I had experienced before cleared and it operated as it should.

Went to work and back, had all gears with unusually high shift points and harder shifts - 1st all the way through 4th, but no TC lockup.

Went to Home Depot, bought an analog meter for TPS verification, tested great. Retested TCM brake, reverse lights, ground, positive and switched positive... all great. Tested TPS thoroughly and all readings were great. Back probed TCM at pin 11 to see if TC lockup signal is sent while going to get a new TPS... no lockup signal was present. Placed probe in to TCM plug 13 just to ensure my testing worked and it did! Happy to see the test worked, relieved that I didn't have to drop that pan again!

Observed back probed terminal 11 on the way home... nothing at all. Plugged in the cheapo scan tool and the TPS low voltage code was gone and only a straight P700 remained. I took that as progress!