Nightwing

I've got a 2000 XJ with 158,000 miles on it and I'm noticing that when I manually shift it into 3rd gear and then back into Drive, when in 4th gear the torque converter wont lock out. It locks out fine in 4th if I don't manually shift it into 3rd but as soon as I shift it into 3rd, and the converter locks out in 3rd, then shift it back into Drive, it doesn't want to lock out. By shutting the engine off and back on I can make it lock out in 4th again. It gave me a P0740 code, cleared it and it never came back. I read on another thread that a guy was getting the same code but his torque converter never locked out, new converter and all of his problems went away. I talked to a technician about this and he said that he'd recommend replacing both the transmission and converter since they tend to be related and I would most likely have metal in my transmission. He also recommended because of the mileage that the transmission could be on its way out and replacing it could prevent a lot of headache down the road. My ATF has been clean and clear and I haven't seen any metal inside of my transmission when I pulled the pan about a month ago. Just kind of wondering if anyone has had a similar problem and or could tell me what they would recommend replacing, as well as if the 3rd gear thing is mechanical or electrical. Thank you in advance

bluejeep2001

I do not have the answer to your question, but i would state your tranny mechanic is unreliable... 150,000 is almost brand new in the jeep world. My first 92 went to the junker at 345,000 with no tranny issues ever, and my current 01 has 325,000 and no tranny issues. I changed the fluid every 75,000 give or take and there was always a little dust on he magnets. While you might have a bad tranny, saying that the both need to replaced due to age and mileage is BS.

zs&tas

I’d have to agree , the trans more than likely is ok

00t444e

It's an electrical issue, definitely not the transmission. The AW4 will last 300K or more.

lawsoncl

Start by testing the TPS. The P740 code is for a bad solenoid, which is fairly easy to replace if you don't mind dropping the transmission pan.

Nightwing

I dropped the pan about a month ago and replaced 2 of the 3 solenoids in it. Only one I didnt replace was the one different from the other 2, is this the one your referring to?

lawsoncl

Yes the t/c solenoid is the different one. I bet your thinking you should have replaced all three about now.

awg

You can test if its working by unplugging the connector alongside dipstick.

Identify plug wire that controls TCC solenoid

run a probe with thin wire to underside of trans pan, and a similar wire from battery +

touch wires together. You should be able to hear the solenoid click on & off, however, its more quite than the others, it performs the opposite function, so you have to listen very carefully with ear against pan

You should also read resistance on that circuit first, It should be about 14 Ohms from harness pin to battery -

That means you have continuity between wires<solenoid< ground