• Welcome to the new NAXJA Forum! If your password does not work, please use "Forgot your password?" link on the log-in page. Please feel free to reach out to [email protected] if we can provide any assistance.

Transmission Solenoids

nhrocker

nhrocker

Jackstand wheeler
Location
Claremont, NH
My rig is a 95, AW4, 231.

Been trying to get it back on the road for a while. Got it running again and it had issues shifting. Everything under the hood seemed to check out (sensors, senders, wiring, etc.) Swapped in another TCU, no change. I checked the ohms for the solenoids today and got good readings for the TC solenoid and the #1, but the #2 solenoid is only reading at 1.46ohms. If it's giving it power all the time, it would mean I'm only running in gears 2 and 3. That would explain the lack of power/acceleration from a stop and the loss of top speed, higher RPMs at higher speeds, and a lack of shifting going on.

Will a blown solenoid give it power all the time? Are the solenoids usually damaged as a result of something else being bad, or do they go on their own?
 
Typically, they go open or a high resistance. 1.46 ohms sounds like maybe the wiring is shorted to ground or maybe the solenoid is shorted internally. I think it's time to pull the pan, unplug the solenoids and measure them directly. You gotta pull the pan top replace them anyway. As a short term fix, you could swap the #2 and #3 solenoids and just live without t/c lockup. Junkyard or ebay are two good options for finding replacements.
 
I actually had been told that my torque converter was shot originally, so I had already picked up a used transmission and converter out of a 96. I just decided to run through the electrical before I pulled my old one out.

My spare trans has about 140,000 miles on it. Would it be worth swapping the solenoid out of that, or should I just order a complete new set and not worry about it again? I found new shift solenoids for less than $100 for both, and new TC lock up solenoids for $67.28.
 
Nominal resistance for AW4 solenoids is, as I recall, 11 ohms +/- three or four.

1.46 is way too low, and your solenoid coil has shorted. This will prevent solenoid operation.

N.B. - you should get similar values for solenoid coil resistance when checking directly or when checking at the TCU connector - although the TCU connector should be slightly higher (revise to 13 ohms +/-.) Low resistance at either point indicates a fault - nominal resistance at the solenoid and high at the TCU connector is a wiring fault in between - locate and service (cheaper than the solenoid!)

Solenoid resistance should be checked at both points - there may be a wiring fault that caused the solenoid to pop on you...
 
5-90 said:
Nominal resistance for AW4 solenoids is, as I recall, 11 ohms +/- three or four.

Solenoid resistance should be checked at both points - there may be a wiring fault that caused the solenoid to pop on you...
Click to expand...
Yeah, from what I've found it should range from 11-15 ohms. At the TCU I got about 12.5-13 ohms for the other two solenoids. It was a dead giveaway when the #2 was only showing 1.46.

I plan on pulling the pan no matter what, so if I can figure out which wire is which I'll be able to check it at the connector by the firewall and right at the solenoid as well.
 
nhrocker said:
Yeah, from what I've found it should range from 11-15 ohms. At the TCU I got about 12.5-13 ohms for the other two solenoids. It was a dead giveaway when the #2 was only showing 1.46.

I plan on pulling the pan no matter what, so if I can figure out which wire is which I'll be able to check it at the connector by the firewall and right at the solenoid as well.
Click to expand...

OK - thanks. Apparently, I was a little off, and it should have read "13 ohms +/- 2."

Still, I knew I was close enough, and that the #2 reading you got was way out of range...!
 
xjtrailrider said:
Will it go into 1-2 manualy? When my #1 went out I could still drive it by shifting manually untill I could find parts.
Click to expand...
With power to the #2 it shouldn't let it drop into first, or go into fourth. I hadn't thought of a solenoid being on all the time as the problem so I never tried pulling the fuse to try shifting it manually. I figured if one had gone it would be off...

I tossed my interior back together enough so tomorrow I'll be able to pull the trans fuse under the hood and give it a try manually. If it drives "normally" and will go into 1st, 3rd, and 4th then I'll know it was just that one bad solenoid. I'll swap in at least that one out of the spare trans, toss in a new filter, gasket, and fluid and hopefully be back to driveable.

I'm wondering now though if this has anything to do with the 1st and 4th lock out switch I added (followed gojeep's write up). I've been running it for a couple years with no problems, but it's a possibility.
 
nhrocker said:
With power to the #2 it shouldn't let it drop into first, or go into fourth. I hadn't thought of a solenoid being on all the time as the problem so I never tried pulling the fuse to try shifting it manually. I figured if one had gone it would be off...

I tossed my interior back together enough so tomorrow I'll be able to pull the trans fuse under the hood and give it a try manually. If it drives "normally" and will go into 1st, 3rd, and 4th then I'll know it was just that one bad solenoid. I'll swap in at least that one out of the spare trans, toss in a new filter, gasket, and fluid and hopefully be back to driveable.

I'm wondering now though if this has anything to do with the 1st and 4th lock out switch I added (followed gojeep's write up). I've been running it for a couple years with no problems, but it's a possibility.
Click to expand...
out of all the wires that got melted in that lil fire in august were any trans related?
 
lawsoncl said:
The "filter" is basically a metal screen, so it can be flshed with carb cleaner instead of being replaced.
Click to expand...
I wanted to get a new gasket for it as well, and they came as a package. I already have them. I figured why mess with cleaning the old one out when it only cost me like $15 for a new one with a cork gasket?
ROBZ95Xj said:
out of all the wires that got melted in that lil fire in august were any trans related?
Click to expand...
I think some of them were indirectly. Thinking back on it though, I think this problem came before the fire. After doing all the work on it when I took it for a test drive I remembered that it had felt like it had lost power and my top speed was way down. I had restarted it and it seemed to drive fine back home. The next morning was when I left to head to your place and part way down it started revving up and slowing down. I think it might have been going then, which made me lose 4th gear. I let it rev up to try to compensate for being in 3rd instead of 4th, so it ran hotter, which dumped even more/hotter exhaust out of the leak onto the wiring...
 
Good news and bad news. I finally got around to pulling the plug for the trans by the firewall and took some readings. On the transmission side of the plug I got 12.2ohms, 12.2ohms, and 12.7ohms. So there's nothing wrong with the transmission as far as I can tell.

Which brings me back to what started this all, wiring. I need to figure out whether the issue is in the harness under the hood, the harness behind the dashboard, or something else. I tested the leads from the male side of the plug at the firewall while I was testing the female side from the trans. I tested it with the plug disconnected, vehicle off, no key in ignition.

Readings, looking at the end of the plug, clip side up:
(N/A=circuit open, no reading)

______________Clip Side______________
16.2ohms---9.32kohms----N/A----9.28kohms
N/A-----------0ohms----.638kohms----Empty
___________________________________

The third one in the top row is the bad one. I know it's the one for the #2 solenoid, and the two beside it are the other solenoids, so I believe it should read the same.

I have a spare engine wiring harness, which includes part of the circuits for this. I'd like to know that it's the issue before I go taking the time to swap it out, but at this point I might anyway. During the small electrical fire I had, it's the harness that was partially damaged. I repaired what I thought was all the damage, but now I'm wondering if there was damage not related to the fire (caused all this in the first place possibly)

Older thread for the wiring issue found here:
http://www.naxja.org/forum/showthread.php?t=927839
 
Sorry for the large number of posts in a row, but anyway...

The spare harness I thought I had isn't going to work. It looks like when someone went to remove it they f'ed it up pretty good. Wires cut, sections worn through, melted parts...

So I'm thinking of just running new wires direct from the TCU to the plug by the firewall. Eliminate the use of the one that's testing bad. Does anyone know if that wire goes anywhere else? Or is it just like what I want to run, from the TCU to trans?
 
The solenoid wires just run from the TCU through the rubber plug in the firewall, to the connector under the hood, and the down to the tranny. I think I'd probably just run a new wire myself as it sounds like the original is broken (maybe in the connector?).
 
Ok, started messing with the wiring. The reading I was getting for the #2 at the connector was actually because of the diode I had installed as part of my 1st and 2nd gear override (from gojeep's site). I checked the ohms on a brand new one I had sitting around and it matched. I also got a weird reading off the switch I had used for the override, so I swapped that out. I tried adjusting the cable for the transmission to see if that was the issue and double checked the fluid level. Took it for a test drive and it still had very little power and shifted horribly (didn't want to shift when it should, shifted when it shouldn't...) but I found that it did go into 1st, 2nd, and 3rd. I believe it went very briefly into 4th, but I'm not positive. At this point I'm thinking of just biting the bullet and swapping in the spare trans.
 
So the wiring is good and the solenoids are measuring the right resistance? Any chance it's you 1-2 switch causing the problem? TPS is the usually culprit for erratic shifting.
 
You must log in or register to reply here.

Similar threads

C
Transmission Not Shifting Past First Gear
Replies
2
Views
70
CBJeeper
C
J
AW4 Problem shifting first to second when hot
Replies
2
Views
1K
cruiser54
C
B
2000 4x4 sport with 4.0 auto trans issues looking for help.
Replies
4
Views
1K
lawsoncl
L
R
No voltage at fuse
Replies
7
Views
195
RCP Phx
R
JohnX
Before SCF, I need to finish....?
Replies
9
Views
92
Carol.92124
Carol.92124
Back
Top