mongold88

So I've got the code P0743 and I've been looking it seems like it's the 3rd shift solenoid, since it's not going into OD. has anyone else seen or experienced this code?

DFlintstone

Until someone else comes along. You might PM Radi. He sold his Jeep and hasn't been on much, but may be helpful anyway. Solenoids can be changed, but the wiring plug for them behind/rear of the dipstick should be checked and cleaned. There might be a grey, and a black. The grey might be for the trans, and the black for the NSS. Not sure there though. I'd check all the wires down there. Here is some more info;


AW4 operation..Radi
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

Radi

Agreed with Dflintstone, possibly a failing solenoid or wiring harness to the trans. I'd check the solenoid resistance to begin with. Since I don't know the year I can't tell you which pins to hit with the meter.
Might give the brake pedal switch a quick check too, although I don't think that sets a CEL.

DFlintstone

HEY Chuck! What? Are you just hiding in the shadows....Telepathy?

Mongo, (and everyone), you should fill out your info so people trying to help don't need to look for it!!!!) (just putting it in post one, or three, is no good at post #20!)

CCKen

Monogold88 said in a previous post: "So I have a 98 cherokee 4.0L 4x4 auto."

mongold88

Sorry I didn't put my info in the first post. But like Ken said I am working on my 98 cherokee 4.0L auto 4x4.

CCKen

P0743 is:

Torque Converter Clutch Solenoid/Trans Relay Circuits

An open or shorted condition detected in the torque converter clutch (part throttle unlock) solenoid control circuit. Shift solenoid C electrical fault - Aisin transmission.

If you have a digital Volt/Ohmmeter you can check the solenoids, trans input and out speed sensors, etc., directly from the TCM connector.

If you want to try this I can dig up a post that I outline the steps to be taken to do this.

mongold88

Ken that would be awesome!

JeepMN

I would appreciate this as well! Getting the same symptoms as him on my 99

CCKen

I couldn't find my complete TCM test procedures but the following will alow you to test the solenoids.

Before beginning verify your transmission fluid is full.

Examine the transmission connectors at the trans dipstick for cleanliness, security, and chafed wires, especially the "TCA" connector. (refer to pic below).



To access the TCM, remove the trim panel and knee blocker below the steering column.

TCM Location:



Before removing the TCM connector disconnect and isolate the battery negative post connector.

Study the TCM pinout below to get familiar with the connector pin cavity configurations.



These are tests you can perform at the TCM connector to see if a solenoid is bad.

You'll need a digital Ohmmeter.

Refer to the TCM pinout below.

Test the Solenoids:

Ignition OFF/LOCK, disconnect battery negative post connector.

Verify the TCM ground connection has full continuity. Using the Ohmmeter, read between pin cavity 24 and a bare metal spot on the dash. You should see near full continuity. If there is resistance, you’ll need to clean the wire ring terminal connections at G101 on the engine block.

Read between pin cav 12, 1-2 and 3-4 solenoid (A), and pin cav 24 as ground. You should see between 11 and 15 Ohms.

Repeat tests at pin cav 13, 2-3 solenoid (B), and pin cav 11, Lock-Up solenoid (C). Again, you should see between 11 and 15 Ohms.

If any one of these tests shows a solenoid with out of range resistance, suspect the respective solenoid is bad.

Note that pin cav 24 is the TCM ground at ground G101 on the engine. It's located at the ignition coil attach bracket studs.
When you are finished you have checked the solenoids from the TCM connector, through the wiring to the TCA connector at the trans dipstick, to the solenoids. If any solenoid resistance is out of spec you may want to unplug the TCA connector and read the resistance of the solenoid(s) from there to the solenoid(s), and if a problem persists you'll have to drop the trans oil pan and read the rsistance of the solenoid(s) directly at their attachment(s). More about this later, if required.

Below is a visual on the solenoid location in the transmission:

Jroc297

DFlintstone

Jrock, you stumbled into a 4 year old thread. Feel free to start a new thread if you like.

Jroc297

DFlintstone

So you nailed it, all is good?

Jroc297