Need help with check engine light and P0740 & P0700 codes

[Jeepinjosh4.0]

Today while driving home a random check engine light can on. Nothing odd to be noted while driving at all. Scanned with my obd reader and it says P0700 & P0740
The P0740 is the main code. It reads tcc out of range. Any ideas/help would be great. The transmission shifts fine and has no issues with driving. Have never had an issue with my transmission up to this point

Also just within the last 3 weeks had my axles re geared. Doubt that has anything to do with it but maybe. Idk

 

[Chris]

It could be one of several things:

1) First replace your automatic transmission fluid with fresh, clean fluid. Clear the codes, then see if this solves it (often times it will).
2) Make sure your transmission fluid level is not low (this too will cause codes often times).
3) Your torque converter solenoid valve is going bad.
4) Your torque converter could be going bad. Not sure how many miles you have, but this is to be expected with higher miles. However, usually when the torque converter starts going bad, there are symptoms other than check engine lights.

 

[Jeepinjosh4.0]

It could be one of several things:

1) First replace your automatic transmission fluid with fresh, clean fluid. Clear the codes, then see if this solves it (often times it will).
2) Make sure your transmission fluid level is not low (this too will cause codes often times).
3) Your torque converter solenoid valve is going bad.
4) Your torque converter could be going bad. Not sure how many miles you have, but this is to be expected with higher miles. However, usually when the torque converter starts going bad, there are symptoms other than check engine lights.

I checked my transmission fluid level when the engine was somewhat warm. Cycled through the gears and left in park and running while I checked it. The level was in the middle of the cold lines?

 

[Jeepinjosh4.0]

It could be one of several things:

1) First replace your automatic transmission fluid with fresh, clean fluid. Clear the codes, then see if this solves it (often times it will).
2) Make sure your transmission fluid level is not low (this too will cause codes often times).
3) Your torque converter solenoid valve is going bad.
4) Your torque converter could be going bad. Not sure how many miles you have, but this is to be expected with higher miles. However, usually when the torque converter starts going bad, there are symptoms other than check engine lights.

I have 119500 miles on the jeep. No issues shifting or anything of the sort. Doesn’t seem to have power loss. Maybe an electrical connection?

 

[Chris]

I checked my transmission fluid level when the engine was somewhat warm. Cycled through the gears and left in park and running while I checked it. The level was in the middle of the cold lines?

I'd fill it to the full line. But I'd also change the fluid. Dirty fluid has been known to cause these faults. It's also the cheapest place to start, and good preventative maintenance anyhow.

 

[Jeepinjosh4.0]

I'd fill it to the full line. But I'd also change the fluid. Dirty fluid has been known to cause these faults. It's also the cheapest place to start, and good preventative maintenance anyhow.

Okay I’ll take a look. & also is there any electrical connections on the transmission I should take a look at?

 

[Chris]

Okay I’ll take a look. & also is there any electrical connections on the transmission I should take a look at?

Well, I'd get under there and inspect just to make sure. Jeeps are always known for finicky electrical connections.

One thing you might try too is simply clearing the codes. I say that because every so often I'd get a random check engine light with no symptoms. I'd reset it with my scanner, and it would never come back again. Which again goes to show that sometimes Jeeps are just finicky when it comes to their electronics.

 

[Jeepinjosh4.0]

Well, I'd get under there and inspect just to make sure. Jeeps are always known for finicky electrical connections.

One thing you might try too is simply clearing the codes. I say that because every so often I'd get a random check engine light with no symptoms. I'd reset it with my scanner, and it would never come back again. Which again goes to show that sometimes Jeeps are just finicky when it comes to their electronics.

Okay I’ll do that. But I’m pretty sure I had the same cel a few days ago but I reset it and it came back. So I think something has come loose maybe

 

[Chris]

Okay I’ll do that. But I’m pretty sure I had the same cel a few days ago but I reset it and it came back. So I think something has come loose maybe

That could be. Fill the transmission and change the fluid though too. With 120k miles, it's necessary anyways.

I'm not sure what would be loose, but it doesn't hurt to look around.

 

[Jeepinjosh4.0]

We’ll see. I really hope the problem just goes away: wishful thinking I know

 

[Jeepinjosh4.0]

That could be. Fill the transmission and change the fluid though too. With 120k miles, it's necessary anyways.

I'm not sure what would be loose, but it doesn't hurt to look around.

If the light keeps coming back on maybe I should see a mechanic?

 

[Chris]

If the light keeps coming back on maybe I should see a mechanic?

It might be worth it, yes. I personally think the transmission fluid is the ticket though. I've seen your problem before, and it was always a transmission fluid change (and topping it off) that caused it to go away.

We'll see I guess!

 

[Jeepinjosh4.0]

Update. Drove to work today with no check engine lights. Felt the converter lock up with no issues. Seemed to ride fine in lockup. No rpm jumps or drops. We’ll see if the light comes on in the usual place when I’m driving

 

[RetiredJim]

Today while driving home a random check engine light can on. Nothing odd to be noted while driving at all. Scanned with my obd reader and it says P0700 & P0740
The P0740 is the main code. It reads tcc out of range. Any ideas/help would be great. The transmission shifts fine and has no issues with driving. Have never had an issue with my transmission up to this point

Also just within the last 3 weeks had my axles re geared. Doubt that has anything to do with it but maybe. Idk

I get 0740 from time to time in my 01TJ . Fluid and transmission operation are all good. Sometimes it clears for a month. The trans was rebuilt 2 yrs ago. I'm convinced it is an electrical connection.


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[Jeepinjosh4.0]

I get 0740 from time to time in my 01TJ . Fluid and transmission operation are all good. Sometimes it clears for a month. The trans was rebuilt 2 yrs ago. I'm convinced it is an electrical connection.


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Continue to get the cel. Definitely don’t think the torque converter is locking up: fuel mileage is suffering a lot. Took it to local shop, he reccomended full rebuild. For 2600.. wtf. Called aamco they seemed more positive about fixing my problem. A

 

[burdetter16]

Continue to get the cel. Definitely don’t think the torque converter is locking up: fuel mileage is suffering a lot. Took it to local shop, he reccomended full rebuild. For 2600.. wtf. Called aamco they seemed more positive about fixing my problem. A

I know this is an old thread but my tj threw this code a few days ago. It’s an 01 with 130k miles, 32rh transmission. I changed the transmission fluid when I first got it back in August, around 126k-127k miles so I don’t think that’s it. It shifts fine, no power loss or anything other issues when driving but there has been a drop in MPG.
Do you remember what yours ended up being? Or any other advice on what to check?

 

[davecarlson98]

I know this is an old thread but my tj threw this code a few days ago. It’s an 01 with 130k miles, 32rh transmission. I changed the transmission fluid when I first got it back in August, around 126k-127k miles so I don’t think that’s it. It shifts fine, no power loss or anything other issues when driving but there has been a drop in MPG.
Do you remember what yours ended up being? Or any other advice on what to check?

Hi, I am getting P0740 on my 06....wondering if/how you fixed this?..thanks, Dave

 

[burdetter16]

Hi, I am getting P0740 on my 06....wondering if/how you fixed this?..thanks, Dave

I wasn't having any symptoms when I posted that so I didn't do anything until about a month ago when symptoms began to occur. I replaced my tranny fluid but that didn't fix anything. After doing some research I think it is the TCC solenoid or maybe even the torque converter itself. I decided fixing either of those is a little beyond my skill level (especially since my TJ is my only vehicle) so I am taking it to the shop in the morning :/ I report back what it is once I find out.

 

[davecarlson98]

I wasn't having any symptoms when I posted that so I didn't do anything until about a month ago when symptoms began to occur. I replaced my tranny fluid but that didn't fix anything. After doing some research I think it is the TCC solenoid or maybe even the torque converter itself. I decided fixing either of those is a little beyond my skill level (especially since my TJ is my only vehicle) so I am taking it to the shop in the morning :/ I report back what it is once I find out.

thanks bro...good luck

 

[negro2006]

Anyone ever found a solution to the problem above?