P0740 on a 1997 32RH

[Ken G Ford]

Long story but...... had the engine rebuilt, then Transmission got rebuilt around 600 miles ago.
Then rear main seal covered under warranty so took it back t engine rebuilder. Wen to pick it up and for what ever reason my new batter was low and wouldnt turn engine over. Mechanic went to jump it and I think he did something wrong as it appeared the computer was now blown. New Rebuilt computer installed and after bringing it home yesterday, decided t tke it for a short drive. Check Maint Light came on and I got a P0740 Torque Conveter Clutch Circuit Open code. I did notice that as I accelerate normally the transmission would kick down a gear intermittently. Assumed that cable needd to be adjusted but are the two related ? I thought the 32RH was a 3 speed with NO Computer Connection ?

 

[Jerry Bransford]

The 32RH shifts purely hydraulically but its lockup solenoid for the torque converter is controlled by the PCM.

 

[Ken G Ford]

So it that to say the issue appears to be PCM related?

 

[Ken G Ford]

or lockup solenoid which from my understanding is inside the transmission on the Valve Body?

 

[Ken G Ford]

I also noticed that you gave advice to others that included re-seating the three large electrical connectors plugged into the PCM ?

 

[hear]

or lockup solenoid which from my understanding is inside the transmission on the Valve Body?

The lockup solenoid is on top of the valve body, yes. It connects to the wiring harness at the drivers side back corner of the trans, above the lip of the pan. Adjusting the cable is a pretty good idea no matter what. The lockup function only happens in 3rd gear, and will drop the RPM by ~150rpm give or take, and then when you give it just a little gas it will feel like a tiny downshift as the rpms jump back up, is that more like what you're seeing? If you're much over 35mph it's doubtful you'll get it to kick down into 2nd.

If the intermittent downshift is what you're seeing, pay closer attention to if it's tied to you giving it gas, going uphill, etc. It may just be doing its thing. Or maybe the solenoid is bad and it's randomly kicking on/off. I had a short in the wiring harness that would sometimes throw a P0743. I've never actually seen the P0740 but it's got to be closely related.

Sounds like you've already done some homework but here's a thread with a picture of the external connection.
https://wranglertjforum.com/threads/so-my-2000-tj-throw-a-code-of-po740.6374/

 

[Ken G Ford]

Appreciate all the solid information. Gonna watch it over the next couple of days and really py attention to the 150 rpm drop in 3rd that you talked about. I have a Banks Cat Back and it has been months since I drove it so will take a couple of days to get used to the 3 speed again along with RPM. Will repost in a couple days. Thanks for the information again so now I now what to look for.

 

[Christian.mers]

Appreciate all the solid information. Gonna watch it over the next couple of days and really py attention to the 150 rpm drop in 3rd that you talked about. I have a Banks Cat Back and it has been months since I drove it so will take a couple of days to get used to the 3 speed again along with RPM. Will repost in a couple days. Thanks for the information again so now I now what to look for.

Did you ever figure out what the cause for your P0740 code was??? Thank you!

 

[hear]

Did you ever figure out what the cause for your P0740 code was??? Thank you!

unless you have the identical circumstance, I would start a new thread with your specifics.