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AW4 Solenoid Replacement write-up (no 56k)

FreemansXJ

NAXJA Forum User
Location
Spring Hill, Ks
This started off with a friends 1997 Cherokee Sport. His vehicle is equipped with the 4.0, AW4, and 231 case.

While playing around in 4wd, he noticed his CEL light come on and the Jeep was very sluggish on acceleration. It felt as though the Jeep was trying to take off in 3rd gear. When he manually placed it in 1/2 and accelerated, the Jeep accelerated as it should. He also had to manually shift it to 3rd and OD. While driving down the highway, it became obvious that the TQ was also not locking up (running 3k rpm at 70mph). I had him take it to AutoZone and have the codes ran, and it showed codes:

P0700- Transmission Control System Malfunction
P0758- Shift Solenoid B Electrical.

I did some research on here and a few other sites, and found this write up for PRE-97 models.....http://www.transonline.com/transdigest/magazines/1997-10/Shift Pointers/index.html

On the 97 and up, the TCU is located under the dash on the right side of the steering column. I could not find a diagram that showed how to test the TCU on a 97 up Cherokee, so I did the next best thing. I crawled around underneath and checked all the wires coming out of the tranny. I found no lose wires, kinks, or breaks. This lead me to believe it was a Solenoid.

I started by ordering a 2 pack of Solenoids for $98 here:

http://www.bulkpart.com/Merchant2/merchant.mvc?Screen=CTGY&Store_Code=2&Category_Code=A340solenoid

Remember, the AW4 is the same as the Toyota A340, so this is what the parts will say when you get them.

Once the parts arrived, I went to the parts store and picked up a filter/ gasket kit and 3 qts of tranny fluid. Once I had the stuff I needed, it was time to get dirty....

Start off by draining the tranny fluid using the drain plug...

100_0264.jpg


Next, I removed the 10mm bolts holding the transmission pan on (hint: leave 2 on one side in so the pan does not fall to the floor when you break the seal on the gasket...saves on the mess)...

100_0265.jpg


Continued.......
 
I had a heck of a time getting the dipstick tube loose, so I left it attached to the pan. To do this, you will need to remove the bracket that holds the tube to the bellhousing (13mm). This can be easily accessed from the engine compartment...

100_0263.jpg


Once I had the pan dropped, I got a better look at the internals...

100_0266.jpg


100_0268.jpg


Here is a quick MS Paint label job of the solenoids. The front of the Jeep is on your right, so the #2 solenoid (b) is the one all alone.

#1 1/2-3/4 shift solenoid
#2 2/3 shift solenoid.
OD- OD solenoid.

100_0268b.jpg


Next, remove the 4 bolts holding on the tranny filter (which holds a suprising amount of fluid...lol)..

100_0272.jpg


Now we use the 10mm again, and remove the #1 and #2 Solenoid bolts. Once you have the bolt out, the Solenoids merely pull straight out.

Here is the old (right) and new (left). Notice the new solenoid has a ground wire. This is attached to the bolt when you re-install the solenoid

100_0271.jpg


Continued...
 
To install the new solenoids, you merely push them in to the hole where the old solenoid was. You will then attach the supplied bracket to the solenoid and bolt it down. Remember to attach the ground wire to the bolt!! The new solenoids come with a longer wire, but a little routing can solve the problem.

New B (#2) Solenoid installed...

100_0274.jpg


New #1 Solenoid installed....

100_0275.jpg


You will now install the new Transmission filter, using the original bolts. Once it is installed, you can clean your pan and transmission housing of old gasket. Now you are ready to re-install the transmission pan. Don't forget to put the drain plug back in and re-attach the dipstick bracket.

I started off by putting 2 qts of tranny fluid in. I hooked the battery back up and started the Jeep. I then ran it through the gears, and it worked :) I took the Jeep for a quick test drive and it solved all the tranny issues. The jeep would take off in 1st, shift on its own, and the TQ would lock-up as it should. After the test drive, I checked the fluid level and added 1 more quart.

I hope this helps and let me know if you have any Questions.

JOhn
 
On my 95, the solenoid furthest to the back of the Jeep was hooked up to D16 on the TCM connector. YMMV if you have a different year.
 
Did you use any RTV when you reinstalled the pan gasket or did you just use the gasket supplied with the filter kit?

I actually used both. I used a very light skim layer of RTV on the pan to hold the gasket in place while I installed it. I also put a skim layer in the tranny. It hasn't leaked yet :)

John
 
Great write up. I got the same codes with my 97 but never noticed any shift problems. Changed fluid and cleared the codes a few times. Probably only a matter of time until I replace mine. Thanks
 
I've got everything sitting here to do the exact same thing on my jeep, probably knock it out tomorrow. Ill report back with results/problems :greensmok
 
I can NOT get the 13mm on the bracket off, so I bent it out of the way the best I can, and yes the RTV removal is going to SUCK. About to put the new filter in and then the solenoids....
 
For that 12mm for the dipstick bracket...

put a socket on it, and a jack handle on the end of the socket. It'll break it free that way. I wrestled with it for like 30 minutes before I did it with the jack handle. Worked like a charm.

Be careful when you remove the solenoids .. I broke all the little tabs off the solenoid wiring harnesses.
 
Everything worked out fine, thanks again for the write up...I now have 2nd gear and torque back!

Anyone know what the ATF capacity is supposed to be on the AW4? I did 3 quarts.
 
FYI.... From the service manual.


CHECKING VALVE BODY SOLENOID
With oil pan removed, disconnect electrical connector from
valve body solenoid. Using ohmmeter, check resistance between valve
body solenoid electrical terminal and solenoid mounting bracket.
Replace valve body solenoid if resistance is not 11-15 ohms.
 
FYI.... From the service manual.


CHECKING VALVE BODY SOLENOID
With oil pan removed, disconnect electrical connector from
valve body solenoid. Using ohmmeter, check resistance between valve
body solenoid electrical terminal and solenoid mounting bracket.
Replace valve body solenoid if resistance is not 11-15 ohms.

It's much easier to check them by measuring at the transmission computer wiring harness. That might catch a wiring issue between the computer and the solenoid as well. If they measure bad there, then its time to pull the pan.

DravisAR - Glad to hear it went smoothly. 3 or 4 quarts sounds about right for just dropping the pan. Most of the fluid stays in the tranny, converter, cooler, etc.
 
Everything worked out fine, thanks again for the write up...I now have 2nd gear and torque back!

Anyone know what the ATF capacity is supposed to be on the AW4? I did 3 quarts.

Glad it helped :cheers:

I started with 2 quarts, let it warm up, checked it, and had to add another quart.

JOhn
 
I had p0758 stored as well. Replaced both the shift solenoids and the trans starts out in first as normal now, but the transmission shift through the gear too fast were talking 15-20 miles per hour and in 3rd gear and it lugs the engine. This only happened after replacing the solenoids. Will recheck my fluid level any other thoughts? No Fault codes have returned.
 
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