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Codes PO700 and PO743 (I tried the search)

S

Sitting Bull

NAXJA Forum User
Location
Atlanta, GA
Hello xj doctors, let me describe the patient...

1998 4wd, 4.0, what I beleive to be an AW-4 tranny.

The check engine light came on, I took it to A-zone and they told me codes P0-700 and PO-743. Both in the tranny, the second in the torque converter.

I tried the search engine but didn't get very far. I was hoping this would be a common problem, but doesn't look so great so far.

Is there any type of easy, typical problem that I can check? Where should I start? I'm fairly mechanically inclined on the older stuff (th400's), but no too good with the wifes DD just yet.

Any help would be greatly appreciated!!!
 
Last edited:
Here's what they mean. Time for a manual. Sorry but this is all I've got.

700 The automatic transmission computer or Aisin computer has a problem
743 Torque converter clutch (part throttle unlock) solenoid circuit problem - shift solenoid C electrical fault
 
I was just going to grab my manual from the garage and see what Sitting Bull was looking at.

Doesn't sound like a hoot. Sorry Bull.
 
Both of those codes are probably related. I'd suspect a bad TCC solenoid, or maybe a wiring problem from the trans to the TCU (located under the glove box).

Does it drive OK, just dosen't lock up the torque converter?
 
It doesn't seem to affect driving...at least not yet. I unhooked the battery to reset the computer - and to see if the check engine light would immediately come back on. It went around the block (2 mile block) just fine. Light stayed off.

I'm not as familiar with this stuff as I need to be, the acronyms are confusing me a little. I'll do some more searching to figure out what they are - but if your going to add to your post, please spell it out a little more if ya don't mind. Newbies suck...LOL

I do really appreciate your guys help, I'll check out some of the wiring this weekend.
 
<hijack>

I hooked my XJ to a scanner today and got a 700 code as well, came out as tranny solenoid 2 faulty (at least on the Snapon scanner). So could it just be a sticky solenoid or what?

Any help is appreciated. On a side note I have absolutely no clue what the hell a tranny solenoid does/is/located.

Thanks fellers.

</hijack>

Thanks guy for letting me hijack, hopefully both of us can find answers.
 
Any help with the acronyms and locations of these doo-dads so I can check the wiring out? The light just came back on again - looks like it's for real anyway.

Could this be related to the NSS? Does it just need a good cleaning again or is the torque converter a completely different sensor??

Thanks!!!
 
SittingBull, sorry about the confusion. The TCC solenoid is the Torque Converter Clutch solenoid. It's what it says, it locks up the torque converter.

The TCU/TCM is Transmission Control Unit/Module, and is what controls the shifting on the electronically controlled transmissions. It has a multi-pronged plug-in, and I'd check it first for a loose connection. Not sure how hard it is to access on a 98, but should be located under the passenger side dash.

There's a test you can do to the trans solenoids using a multimeter; that would be a good idea before pulling the pan to replace the TCC. I'll see if I can find the post describing it.....
 
Bump

Runnin'OnEmpty - I was just wondering if you had ever looked for that test. I have a '98 4.0 auto with the same codes showing up (shameless thread hijack) - however, all of my searching seems that these problems are related to AWD, and mine is a 4wd. Check engine light just came on today. Disco'd the batt for 30, and the light is still there. Shifts fine, backup lights work, can only start in park... kinda at a loss! :doh: Thanks!

As a side note, :NAXJA: rocks. I have only had my XJ for a month now, but have already learned a ton! Thanks guys!
 
my 98 had the same codes turned out to be the solinoid. i got one at a pick&pull out of a 91 i think it was. it was bigger but it bolted up fine and works. you have to drop the pan to get to it
 
JeepinTone said:
<hijack>

I hooked my XJ to a scanner today and got a 700 code as well, came out as tranny solenoid 2 faulty (at least on the Snapon scanner). So could it just be a sticky solenoid or what?

Any help is appreciated. On a side note I have absolutely no clue what the hell a tranny solenoid does/is/located.

Thanks fellers.

</hijack>

Thanks guy for letting me hijack, hopefully both of us can find answers.
Click to expand...

The AW4 is an electronically controlled transmission, and the solenoids are the electrical actuators within the transmission that effect the shifts on command from the transmission control module. There are two which in various combinations determine which of the 4 gears you're in, and a third which locks up the torque converter. They can be accessed pretty easily by removing the pan. But I'd check wiring connections, etc. before assuming the solenoid itself is bad.

I doubt the scanner would detect a sticky one, since a solenoid is basically just an electromagnet. It's more likely that it detected an electrical fault, either too much or too little impedance.
 
Wow, I wish I had searched before I posted my topic. Mine is a 97 with the same codes. The Jeep drives completely normal, like there is nothing wrong, other than the check engine light. What has everyone done to fix this?
 
i have a 98 xj with the code 700 only. My problem is that i wont have overdrive. it's hit or miss everytime i turn the key on sometimes i have overdrive sometimes i don't. but the check eng is always on. if i go offroad sometime the check eng will even go out. I'm guessing solenoids going to check this weekend. any suggestions?
 
leeman426 said:
i have a 98 xj with the code 700 only. My problem is that i wont have overdrive. it's hit or miss everytime i turn the key on sometimes i have overdrive sometimes i don't. but the check eng is always on. if i go offroad sometime the check eng will even go out. I'm guessing solenoids going to check this weekend. any suggestions?
Click to expand...
Some info from my 01 FSM
TRANSMISSION RANGES AND SHIFT LEVER POSITIONS
The AW-4 transmission has six ranges and shift lever positions. Park, Reverse and Neutral are conventional and mechanically operated. The 1-2, 3 and D ranges provide electronically controlled shifting. The 1-2 position provides first and second gear only. The 3 position provides first, second and third gear.The D range provides first through fourth gear. Overdrive fourth gear range is available only when the shift lever is in D position .
TRANSMISSION CONTROL MODULE DESCRIPTION
The module determines shift and converter clutch engagement timing based on signals from sensors.The valve body solenoids are activated, or deactivated accordingly.
The transmission range sensor is mounted on the valve body manual shaft. The sensor signals shift linkage and manual valve position to the transmission control module through an interconnecting harness. The sensor prevents engine starting in all gears other than PARK or NEUTRAL.

So, after studying all of that, it seems to me you may not have overdrive if your NSS/Range Sensor has an intermittent connection in the Drive position.

Just as cleaning the NSS switch fix's Park/Neutral start problems/symptons, I would bet that cleaning the switch may clear up shifting/solenoid engagement symptons, due to the fact the TCM needs to know what shift position you are in.
 
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