Ok, so I kind of asked this question before, but I think the title threw a lot of people off. Here are the specs...

1998 Honda Accord lx, 2.3 4cyl

Recently serviced transmission (Rebuilt), Clutch Solenoids, and Torque Converter.

When I first received my car from the shop, I received no indication of a warning. Stopped at the gas station filled up, and continued on my way. Got to the freeway, and began to hit freeway speeds. about 45 seconds later, the engine light comes on. I check it at the auto parts store, p0740 is what came up. Clutch Solenoid Circuit malfunction.

So I took it back to the mechanic, and he tests everything, and says the solenoids work fine. He didn't however take it for a test drive, because if he had, the engine light would've came on again, like it did as I drove away the second time, and reached freeway speeds. Again it came on after about a minute on the freeway.

So I call him, and he says its my sensor.

And so all know, I can never come to a stop getting onto the freeway, I'm always coming from rolling. But when I am lucky enough to reach a light before entering freeway speeds, I can feel all 4 shifts. So it's not like my car isn't shifting to the fourth gear.

Another possible problem:
When I come to a stop light, I feel a small downshift. But what I believe to be even worse is that if the light all of a sudden changes green as I am slowing down to a near stop, and I hit the acceleration again, there is a small sputter before it catches the gears. However when I come to a full stop, with the small downshift I mentioned, I can take off with no sputter.

My Questions:

What sensor would pull the code p0740?

I know the down shift is apparently not supposed to happen, but could the p0740 code be causing this also?

Same, could the p0740 code cause the slight sputter if you're coming to a stop, and have to pull off before completing the stop?

Any help would be greatly appreciated.

 

I am very familiar w/ this code, having lived w/ a 97 Acura 2.5TL that had this code for several years. I chose to live w/ it as repair required pulling the trans to find the hydraulic fault, probably in the torque converter.

It can be the lock-up solenoids only if they are electrically sound, but non-functioning. An electrical fault in LU solenoids sets another code, not P0740. In other words, P0740 is a hydraulic fault, not an electric fault.

This code is set, when speeds over 55 mph are present, engine fully warmed, and TCU detects slippage (> 5% ?) between wheels and engine (torque converter not locked). That's why you don't see CEL until reaching freeway speeds.

I'm not aware of a "sensor" directly linked to this code. The VSS and Main Shaft Speed sensors are used to detect slippage. A fault in either of these sets a separate code, not P0740.

Your shift problem may be due to low hydraulic line pressure. One of the checks for P0740 is to check that hydraulic line pressure is in spec. If not, the hydraulic pump is faulty or something is leaking pressure. If your shop did not do this, they are worried that only fix is to pull/repair the trans. They just want you to go away, and quit bugging them. I would insist on satisfaction, if you paid for a rebuild.

good luck

 

Hey Mr. Honda Texas... So, 7 months later lol... my car breaks down on the hwy. When I first got on the hwy, I thought I noticed smoke. But I was smoking a cigarette, so I wasn't sure. On the change to another hwy, which is steep incline for a short distance, I seen plumes of smoke coming out of my car. Pulled over, noticed tranny fluid was leaking. I got it towed from a good friend of mine, and he says, could be a hydraulic problem (Thanks Tex!)...

We towed it to the shop, and the Mechanic said my radiator line from the tranny to the radiator busted. The repair would be a new radiator. 300 dollars later (Yeah I probably got scammed). I get to driving. I'm driving all throughout the side roads perfectly. Nothing wrong. No CEL. etc. I hit the free way, increasing speed till about 65-70 mph. No CEL, I'm getting excited. Look down, and the dreaded CEL.

I read somewhere that the cause could be the case of the wrong Tranny being put in. i.e. a EX model., instead of my lx type model. Could this be the case? And how could I check it?

Also, it seems to have this problem in 4th gear. Maybe 3rd to 4th, but as I understand, anything above 45 mph, is used by the 4th gear. Again, no problems as far as driving through the city streets. But on the freeway, the CEL comes on.

Specs:
98 Honda Accord LX Sedan
4cyl
CEL: P0740 TCC Solenoid Malfunction

Will check my Solenoid, although the Mechanic said he replaced it. For some reason I don't believe him.

Thanks for the advice you gave me before. Again, can you tell me how I can check my Hydraulic line pressure?

 

You can try changing the trans fluid. My experience is you're stuck w/ this unless the trans is pulled and repaired.

Checking trans pressure is PIA. As per Honda's usual MO, they use a special fitting to check trans pressure that was not in the MAC trans pressure test tool I bought (11 fittings and none worked!).

If car is shifting OK, the trans pressure will probably check OK.

good luck

 

But thats what I'm saying... The tranny has been rebuilt, and it's STILL giving me this problem. Like I said... I will be getting off of work, and checking out the Solenoids today. I just don't understand right now. Rebuilt with new Torque Converter... It's killing me man! I need to pass my emissions, and I don't want a stupid CEL stopping me from doing so!

 

You can turn the CEL off and it will stay off unless you drive above 55mph until all tests are complete, then get your inspection sticker. That's what I had to do w/ my Acura TL.

good luck

 

LOL WORD!... I think that will have to be the case... To be honest, I actually thought of that last night... Thanks again, sir!