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P0740 Code...options

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  #1  
Old 06-24-2011, 10:48 AM
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Default P0740 Code...options

I have a 2001 Accord LX with 193K miles on it. I bought it new in Dec. 2000. At 48K, I had a warranty replacement transmission. So the current tranny has 145K on it. About 8K miles ago, my wife was leaving the gas station and ran over a curb upon exiting. She didn't go up over the curb, but went down over it. She said it sounded loud from the bottom of the car when she hit the curb.

Soon after that (Same day) I had the CEL come on while I was driving it. Had the code checked and it was a p0740..TCC fault. I have since changed the Tranny fluid twice and replaced with Honda Trans fluid. It tends to get up to 3K-3500 RPM's coming out of 1st to second gear with a bit of a rough shift. After that, all seems to function normally. There doesn't seem to be a burned smell or any metallic flakes in the fluid.

I have checked other posts on this and have seen some of the bad news in them. I took it to a Tranny shop and he drove it and said it would really be hard to tell what the issue is without pulling the Transmission to get in and have a look.

My question is, could there have been something, electrically that could have be jacked up by driving on the curb or is this going to have to be the 3rd transmission that I have to put in this car? It is also important to note, this car has been dealer serviced since the beginning. Everything else on the car is functioning ok (knock on wood).

My other question is, if this is something that I can live with for a while, is there a way to get around the fault code as I live in Texas and I won't get through inspection with a CEL on, regardless if it isn't an emissions issue.

Please help!

Thank you!
 
  #2  
Old 06-24-2011, 02:42 PM
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P0740 is failure of the torque converter lockup, however it is a hydraulic fault, and not a lockup solenoid electrical fault (different code is set). The fault is detected by the TCU observing that final drive and input drive shafts are turning w/ slippage. You can reset and it will usually go away until you drive above 55mph, where it will soon reset.

It could be a damaged lockup solenoid caused by the impact, but that seems unlikely. You can remove/inspect the LU solenoids or replace them.

Only good news is you can drive long term w/ this fault. Only downside is slight reduction in gas mileage. Mileage change is not detectable w/ most suburban driving.

How I know this is I lived w/ an Acura 2.5TL w/ this fault for several years. It runs fine, gets 23-25 mpg around town, but only 26-27 on the road. My son drives the car and CEL doesn't bother him, but drives me crazy.

good luck
 
  #3  
Old 04-17-2013, 08:20 AM
Join Date: Apr 2013
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Default P0740 - 2003 Honda Odyssey

Originally Posted by TexasHonda
P0740 is failure of the torque converter lockup, however it is a hydraulic fault, and not a lockup solenoid electrical fault (different code is set). The fault is detected by the TCU observing that final drive and input drive shafts are turning w/ slippage. You can reset and it will usually go away until you drive above 55mph, where it will soon reset.

It could be a damaged lockup solenoid caused by the impact, but that seems unlikely. You can remove/inspect the LU solenoids or replace them.

Only good news is you can drive long term w/ this fault. Only downside is slight reduction in gas mileage. Mileage change is not detectable w/ most suburban driving.

How I know this is I lived w/ an Acura 2.5TL w/ this fault for several years. It runs fine, gets 23-25 mpg around town, but only 26-27 on the road. My son drives the car and CEL doesn't bother him, but drives me crazy.

good luck
I am having P0740 code in my 2003 Honda Odyssey. Per above advise can anyone tell me how do I "remove/inspect the LU solenoids or replace them." ?

What is the location of Lock up Solenoids ?. How do I get there ?. Is this in Transmission Unit ?. How hard it is to replace LU Solenoid ? I am not too technical but i can do basic if it is easy to get to it and replace it.
 
  #4  
Old 04-17-2013, 11:43 AM
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You may not have noticed this is Accord forum. However we don't discriminate. You will however need to identify what engine you have in this Oddyssey.

LockUp solenoids are generally on the exterior of the AT. Exact location of LU solenoids may have to come from a shop manual. Check ebay for a used manual. I saw several at reasonable prices. Unless the solenoid is blocked w/ debris, this is unlikely your problem.

good luck
 
  #5  
Old 06-04-2013, 10:19 PM
Join Date: Dec 2010
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Similar problem, asking for clarification please TexasHonda......

Originally Posted by TexasHonda
P0740 is failure of the torque converter lockup, however it is a hydraulic fault, and not a lockup solenoid electrical fault (different code is set). The fault is detected by the TCU observing that final drive and input drive shafts are turning w/ slippage. You can reset and it will usually go away until you drive above 55mph, where it will soon reset.

It could be a damaged lockup solenoid caused by the impact, but that seems unlikely. You can remove/inspect the LU solenoids or replace them.

Only good news is you can drive long term w/ this fault. Only downside is slight reduction in gas mileage. Mileage change is not detectable w/ most suburban driving.

How I know this is I lived w/ an Acura 2.5TL w/ this fault for several years. It runs fine, gets 23-25 mpg around town, but only 26-27 on the road. My son drives the car and CEL doesn't bother him, but drives me crazy.

good luck
Couple of follow-up questions since I'm having same code problem, right after a transmission rebuild with a 2-year warranty,...........

(and my son accidentally erased my earlier write-up, so this will be summarized which is actually a good thing )

Mainly, if the P0740 code seems to refer to an internal transmission fluid operational fault, which doesn't seem to affect normal shifting in a major, noticeable way, is there any internal damage occurring that will lead to a need for a rebuild earlier than later? I kneel before your expertise and experience, TexasHonda, especially with our Honda's, and since I really don't want to let my recent rebuilders get a hold of my car for any longer ( 2.5 weeks already, and a couple of missing bolts after which I can replace without current problems...), I would rather just deal with the CEL as you have, but I have concerns about whether the TCC slippage leads to premature lock-up clutch wear. Do you know anything specific about that?
My rebuilder said that their job included some improved, HD parts, pump, new valve body, teflon seals, etc...so that it's already maybe 'better' than the original, faulty transmission which came in the car.

That said, there's a real good chance that with such a highly technical transmission adjustment procedure, that they may even mess it up so that it doesn't shift as well as it does now, since they spent over 2 weeks just to get it to this point. Now it shifts fine, but there is a noticeable, somewhat abrupt downshift when coming to a stop, but I wouldn't describe it as "harsh", like it was doing before from 1-2, 2-3....it just releases 'firmly'.

Also, since I do have a solid warranty on the rebuild, would you suggest taking it back to them no matter what, if I can afford more car rental fees such as they may not cover that? (Owner has already cut off about $200 of his bill due to extended delays to rebuild job, and is literally begging me for a positive, online review, difficult now due to what I'm experiencing).

Can you see my dilemma? Any advice would be appreciated.
 
  #6  
Old 06-04-2013, 11:10 PM
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I will try to explain.

When you are driving with a good transmission at highway speeds, you will notice a slight drop in rpm as you cruise at one speed. This is the torque converter locking up to the axles. This is done to drop rpm and increase gas mileage.

The engine computer is detecting that the torque converter is not locked up to the axles. I will guess that the engine rpm and the speed of the car are two of the sensors (along with others possibly) the engine computer used to set the fault.

A torque converter that does not lock up isn't damaging the transmission. I think the lockup happens with hydraulic pressure, so your transmission rebuild may have some other issues.

I would definitely call the place up that replaced the transmission and tell them about the code. Let them troubleshoot the problem.
 
  #7  
Old 06-05-2013, 12:30 AM
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ok....Thanks PAhonda....I will let rebuild shop know about the problem, only because they really need to have this one done right on their own end, and maybe I will be better off when they get a 3rd look at it (because when they had it for over 2 weeks, the excuses for delays were all about, "You need a new valve body because the one in there was shot", and "we see why it isn't shifting properly, due to a defective sprag that we installed.....so we need to order a new one....."We want to do the job right the 1st time"....."I need to test drive it, and I don't have time to do that today....", "I know this is frustrating, but we want it to be fixed RIGHT, as you do....."

This while they already had $1600 cash money in advance, 626 of which was for remanufactured valve body ($600 more pd on delivery). You're right. I guess I should put it back on them and kindly demand that they do the job as they said they do "every day of the week". "I've got 3 more coming in next week....." Like they're so busy with our problematic Honda tranny's, even from other shops who can't fix 'em, but a lot of their work is simple trial and error. I get that it's a delicate science of a mechanical nature, but come on.....parts, bands, adjustments, installation and configuration.......WTF?!?!
 
  #8  
Old 06-05-2013, 05:53 AM
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I agree w/ PAH on this issue. I would not be satisfied w/ a permanent P0740 on a rebuilt trans. They should repair as necessary.

good luck
 
  #9  
Old 06-05-2013, 08:01 AM
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I had similar issue with 2003 Odyssey code P0740 and first and second gear was getting stuck. I tried cleaning Lockup solenoid and installing new screens but did not help. I ended up getting rebuilt trans for $950 with 1 year warranty. I did not have good luck with solenoid cleaning but you may try and it may work for you. I have seen some people had success with solenoid cleaning up.

There is full write up on this site on entire process:

http://dvpatel.homelinux.com/herrhau...lve.pdf‎
 
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  #10  
Old 06-08-2013, 08:11 PM
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Still resisting taking car back to original shop, even for warranty work, I performed TCC solenoid testing and it showed 17.3 ohms (within 12-25 ohm range), and both solenoids tested well with strong, regular, 12v "clicks".

Removing TCC solenoid assy and checking screen showed no foreign matter whatsoever. I may perform drain/refill fluid procedure with "ACTUAL" Honda fluid, since I remember the rebuild shop owner/manager telling me that "Sure, if you want me to replace with Honda fluid, either you can buy it, or I can get it at a cheaper price....its called........." (something I can't remember, but was NOT 'Z1'....he said it was the same thing. Since I didn't stop and grill him about the differences at the time, I'm afraid he did not refill with Genuine Honda ATF, but merely a "suitable alternative." The post-rebuild fluid seems too "red", and more viscous than I recall Z1 to look like, so I may replace fluid with Z1 to see if that makes any diff in TCC performance and P0740 codes I'm still getting over 58mph. Adding insult to injury, he charged me $100 flat for his "less expensive" Honda ATF, and I was SO freakin' anxious to get may car off his lot after 2 weeks that I didn't care to point out that the car only takes 6.4 L for a dry-fill, and since I buy quarts for @ $8.69/ea. at local dealer, that only equates to $64.75 including tax.....I know this makes me look stupid that I let him be like this, but I just dealt with all delay excuses for the 2 weeks, trying not to lose it. Not a pleasant memory, that's for sure. Dang, the mechanic had my car longer than I did since purchased! And of course the warranty specifically excludes car rental fees in case of warranty work. In that case, if I have to take it back to him, it won't be pretty. Kinda seems to me that a "real good job" hasn't been done after all......

If a thorough, but not flushed fluid change doesn't keep the dreaded P0740 code away, then I will def be taking it back to him to fix until it's fixed properly. I'm $2300 out, (2500 incl. car rental) already as it is, and I'm not buying a new TCC solenoid assy just to see if that works.

Update later..........
 


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