AW4 solenoids

So i have spent a good part of the day working on my MJ, and researching on , about my AW4's shift problems. It works fine except it will not shift out of first when in D. I have replaced the TPS, with one that i know works, and tested the voltage. When closed the TPS reads ~4.85V, and when open, it reads ~.87V. I have also installed a working NSS, and now the reverse lights work. I found this link... http://www.transonline.com/transdigest/magazines/1997-10/Shift Pointers/index.html that helped me LOTS. however, when i went to test the solenoid resistance, on the connecter that pluggs INTO the TCU, i ran into a snag. it appears that there are not the right ammout of pins, or maybe i have the controller upside down, because what I THINK is #C15 is non existant. I will get a pic of what i am talking about.

another question i have is now exactly do i test the resistance on the pins? i put the dial on 200ohms (200 is the lowest value my miltimeter has), and put the red lead into a pin, and nohing happens. do i need to ground the black, or do i just read from the red? is there another pin that i need to put the black lead into?

sorry if this has been answered before, but i have searched for a good 2 hours today. thanks in advance for your help!!

Easiest to check the solenoids directly - drop the pan to get to them. Isolate components to find a fault...

You'll need to touch both probes to test - touch one to the tab where the wiring connects, and the other to the solenoid case (in this case, it doesn't matter which is which - solenoids are not polarised.) You should see 11 to 15 ohms through the solenoid coil.

Once you've established that those are good, then work your way out, doing continuity checks on each segment of wire until you get a shonky reading. Wiring typically averages .01 ohm/foot, in most automotive gages (but just use the "beep/continuity" function on your meter, and go forward from there.)

When using the "low" scale (200 ohms is typical,) you just read the meter directly. No conversions required...

5-90

Yes, ground the black lead to the chassis or a good ground point. I prefer checking at the TCU connector instead as that checks the wiring to the tranny as well. Also avoids messing with the pan. If there's a problem, then I start wringing out each section.

You might be looking at the connector upside down. Are on the conenctor to the box under the passenger side of the dash? I believe the wire colors are:

C16, Solenoid 1 - Dark Blue with white stripe
C15, Solenoid 2 - Violet with white stripe
C14, Solenoid 3 - White with black stripe
C3, Rear Speed Sensor - Tan with black stripe
D14, +12volts - Red
D16, Ignition 12 volts - Yellow

In particular, you want to check solenoid 2. In first gear, solenoid 1 is energized. To shift to second gear, both #1 and #2 get power. Solenoid 3 is for the torque converter lockup.

Also, I noticed something in the AW4 diagnosis link you posted. Testing for 5-8 volt pulses on C3 is correct only for 1996+. Before then, the sensor was a reed switch that connects the sensor wire to ground once per pulse so you'd want to use the ohms scale on your meter and not voltage. If that sensor is bad, the TCU will always think you're sitting still and never try to upshift.

You might be looking at the connector upside down. Are on the conenctor to the box under the passenger side of the dash? I believe the wire colors are:

C16, Solenoid 1 - Dark Blue with white stripe
C15, Solenoid 2 - Violet with white stripe
C14, Solenoid 3 - White with black stripe
C3, Rear Speed Sensor - Tan with black stripe
D14, +12volts - Red
D16, Ignition 12 volts - Yellow

In particular, you want to check solenoid 2. In first gear, solenoid 1 is energized. To shift to second gear, both #1 and #2 get power. Solenoid 3 is for the torque converter lockup.

Also, I noticed something in the AW4 diagnosis link you posted. Testing for 5-8 volt pulses on C3 is correct only for 1996+. Before then, the sensor was a reed switch that connects the sensor wire to ground once per pulse so you'd want to use the ohms scale on your meter and not voltage. If that sensor is bad, the TCU will always think you're sitting still and never try to upshift.

Click to expand...

Um.. Is that in a FSM? If not where do you find info like that at? I wish that more of the tech on our forum was this detailed.

It's from my 95 FSM, but I happen to know the colors are the same for an 89 since I did a tranny swap. The wire colors noted in the diagnosis link you posted were close, they just neglected to mention the striping.

i went out yesterday, and put my multi meter on the wires. i was getting very low numbers for all three solenoids. im going to go up later and re-test everything to make sure that i was not miss reading.

i did go over to my junk XK that was shifting fine, and just for the heck of it put the meter on that. the ohms were in the 50s...and i was quite perplexed with that. maybe a reading was wrong. but i know it was shifting fine. worst comes to worst i will drop the pan on the XJ and the MJ and swap the solenoids to see if that helps.

ANOTHER OBSERVATION that i noticed was that when the TCU is plugged in, and the drive selector in 3, the tranny is in 1. when the TCU is unplugged, then 1-2 is in first gear, 3 is in 3rd gear, and D is in 4th gear. im pretty sure that this issue is electrical, and i think its the solenoids. any other oppinions?

TwistedSymphony said:

ANOTHER OBSERVATION that i noticed was that when the TCU is plugged in, and the drive selector in 3, the tranny is in 1. when the TCU is unplugged, then 1-2 is in first gear, 3 is in 3rd gear, and D is in 4th gear. im pretty sure that this issue is electrical, and i think its the solenoids. any other oppinions?

Click to expand...

Putting the selector in 3 with the TCU plugged in, just means it won't shift past 3rd gear. With TCU unplugged, it should act as you described. That is the first test listed in the FSM to verify that all the mechanicals are working. Your problem is most likely electrical. In order of likelyhood from what I've read so far are - bad TPS, bad solenoid, bad TCU.

What was the resistence of the solenoids? Should be 11-15 ohms. They could still be sticky even if the resistance is correct. I don't have a diagram handy of which solenoid is which, but they are all identical, so you could swap them around within the same tranny and see if the problem changes.

A bad TCU can be verified by looking at the solenoid outputs or swapping in a known good one.

Ok, so I just went out, and got some numbers. On the MJ, I got:

Solenoid 1: 1.3 ohms
Solenoid 2: 1.0 ohms
Solenoid 3: 2.4 ohms

I made sure that I had a good ground, and tested each one twice. Then I tested my parts XJ, and got:

Solenoid 1: 13.0 ohms
Solenoid 2: 12.4 ohms
Solenoid 3: 12.6 ohms

Those are more normal, as they are between 11 and 15 (woohoo!!). Soon, I will be swapping the solenoids from the XJ into the MJ to see if the shifting is fixed. Soes that sound like a good thing to try to you seasoned XJ/MJ people? I have the AW4 manual that I downloaded from pirate, and it shows where the solenoids are. How do I remove them? Are there screws holding them in? And when I take the oil pan off, can I use RTV to seal it back up when I am done?

There is a single screw that retains each solenoid (10m/m socket I believe, and I think the screws themselves are M6-1.0 x 20m/m hex heads.) Remove the screw, then pull the solenoid straight away from the valve body - ALONG ITS CENTRELINE - about 1/2" to release it.

Check the solenoids you're going to put in, and make sure their orings are sound. I'd advice replacement, but I don't have the size of them in my notes anywhere, and you don't want to use "hardware store" stuff - it won't hold up to the detergents (it's designed for water and/or mild soap. ATF will dissolve the stuff, given time.)

To install, line the solenoid up on the hole, press it straight in, and reinstall the retaining screw. Torque to 7 pound-feet/84 pound-inches (I've got to finish that AW4 page and get it upped.)

Yes, you can use RTV to reinstall the pan - but a gasket would be preferred. If you use RTV, here's the trick...

Lay a bead about 1/8" round, going around the inside of the screw holes.
Allow to set for about 15 minutes.
Set the pan in place, install the screws FINGER TIGHT ONLY.
Go have lunch.
Come back, and torque the screws to ~5 pound-feet (spec is 65 pound-inches)
Let the RTV set up for a minimum of two hours (overnight is preferred) before filling.

You're honestly better off - and it's less work - to use a gasket. Ask your local for Fel-Pro part number TOS18685 (gasket only.)

While you're down there, it may be a good idea to clean the strainer - remove it, blast it from the top with carburettor cleaner, and reinstall (torque to 7 pound-feet/84 pound-inches.) Don't use RTV there - it's too easy to get into the pickup passage. Reusing the cork gasket on there is fine.

Also, clean off the magnet stuck in the oil sump, and put it back.

Torque the oil sump drain plug to ~15 pound-feet/180 pound-inches, and using a bit of RTV on the threads of the screw won't go amiss, either...

5-90

Well yesterday I went to pepboys, and purchased a new filter, and gasket. Today, I borroewed some torque wrenches from my uncle. Hopefully tomorrow I will start, and possibly finish. I will post up my results.

Have you installed any switches for manual control of your shifting (such as a first/second gear selector swicth and torque converter manual lockup swicth)??

If so, and you you used backlit switches (as I did) just disconnect the ground from those and do without the backlighting. That fixed my problem with incorrect resistances.

mozzer said:

Have you installed any switches for manual control of your shifting (such as a first/second gear selector swicth and torque converter manual lockup swicth)??

If so, and you you used backlit switches (as I did) just disconnect the ground from those and do without the backlighting. That fixed my problem with incorrect resistances.

Click to expand...

nope, its all stock. I have the pan out on the XJ, and am about to pull the solenoids. I'll probobly put all three of them in the MJ tomorrow.

Well I'm ahead of schedule. I was under the MJ working with my mag-lite, and BOY was I chilly!! I installed the solenoids, and torqued them to spec (thx 5-90!), and checked the ohms at the TCU plug......12.4 across the board!!!!! Tomorrow I will seal up the pan, and fill the tranny.

Can somone tell me the propper way to fill the tranny up now? My Haynes manual sux, and my Chiltons is MIA. Thanks.

Mag-Lites are nice, but if you want a VERY good working light, might I suggest a SureFire Nitrolon G2? I nearly always have one in my pocket, and it's about three times brighter (and a lot whiter!) than my 3D Mag in the back of the truck. Fits neatly in my fist, too...

5-90

the AW4 fills through the tranny dipstick

I found Go-Jeep's site. I think I understand now. I'll post up results of my test drive tomorrow.

($*&(@#*&$(@#!!!!!

It didnt work. I put the 3 "new" solenoids in the tranny, replaced the filter, and the gasket. Filled up the tranny, and cycled through the gears, and left it in N for a minute. I took it for a test drive and the same thing happened. Put it in D, and its in 1. Put it in 3, and its still in 1. Unplug the TCU, and D is 4, 3 is 3, and 1-2 is 1. I tested the resistance on the new solenoids, and they are the SAME as the old ones, and I tested the resistance on the old solenoids, when I took them out, and it was about 12. Somthing else is up, and I'm NOT going back into that transmission...its a royal PITA. And I'm pissed that its still NOT shifting!

Any other ideas to try?? It has a tranny cooler, so I'm just contemplating running it like a manual.

(I understand your frustration, but please do try to play nice. This isn't Pirate, you know...)

I'm thinking bad TCU or failed rear speed output sensor. The speed sensor is a magnetic switch that closes once per revolution and can be checked pretty easily with the meter. Have you tried swapping the throttle position sensor (TPS)?

You said you have a parts rig, if it still has the TCU and TPS you could try swapping those. You can swap the rar output sensor too, but it's in a bad spot behind the xfer case shifter linkage plate.

I am using the TCU, and the TPS from the parts rig. I think that this TPS is bad, and will be switching back to the old one (not shift related...just over-revs lots of times when I start it). I will be checking the speed sensor, and I will report back. Thanks lawsoncl.

5-90, my apologies...I stepped out of line. It wont happen again .

So I just went out and stuck my milti meter into more connectors. Heres what I did. I jacked up the rear of the MJ, and put the shifter in N. Put the red lead into the TCU connector pin C3, grounded the black and started to turn the wheels (the key was ON but the engine was OFF). The DS was turning, and the whole time (maybe 5 revolutions) the multi meter read 0. I plugged in the TCU, and did the same thing...the meter read ~7.5v, even when I turned the wheels, and the DS was spinning (again about 5 revolutions). I also checked the solenoids that I just swapped in, and they appear to be doing the same thing as the old ones...all about 1.5ohm. What would cause them ALL to do this...bad rear speed sensor?

EDIT: I got some of the info from this page 3 http://www.transonline.com/transdigest/magazines/1997-10/Shift Pointers/index.html