Hello to everyone on the forum and thank you for your help.

I understand that many people have transmission problems associated with the 6th gen accords. I have looked at many threads on the forum about this issue and i have a basic understanding of what is going on with my car but i could not find any that are specific to my situation. i am a decent DIY mechanic however, this problem has got me a little confused.

STORY: car has about 170K miles. a few months back, my car started to shift a little roughly when accelerating but not enough to be concerned about. about 2 weeks ago, it started shifting a little harder and more frequently between all gears. in the last week or 2 i got a MAINT REQ and CHECK ENG light on the dash. i work at autozone so i got out the trusty OBD II and took the codes from my car. [P0420 Catalyst System Efficency Below Threshold (Bank 1) and P0740 1.Torque Converter Clutch Circuit Malfunction 2. open or short circut 3.poor electrical connection 4.failed TCC system] i cleared the codes that day and the next day the MAINT REQ and CHECK ENG lights were back on. in the last week, the problem has been getting worse. the transmission will slip while accelerating from 1st to 2nd to 3rd and when it catches, its a violent jerk and clunk. i have gone to a few transmission shops and i get a different answer every time...

WHAT I KNOW:

• there is a major problem with the 6th gen honda transmissions and honda has not issued a recall.
• the transmission seems to have got these problems rather quickley
• the trans fluid has a slight burn to it but not really bad, the color an fluid level is fine.
• there are no metal shavings/chips on the dip stick
• it will slip intermittendly between all gears weather hot or cold
• the trans will shift hard between gears while accelerating with a clunk sound and a jolt (usually from a complete stop)
• it will shift usually around 2.5 - 4 thousand RPM
• i have not pulled the codes again to see if i have any more or new codes but i will post a reply very soon
• half of the threads i have researched point to an electrical problem with the TCC solonoid or attached wiring. a few even said replacing the ECM worked. the other half said to replace/rebuild the transmission.
• i believe i am outside the window for any lawsuit aginst honda and i dont think i could even be compensated any %edg by american honda since it has over 109K miles
• the transmission shops cannot give me a straight answer

QUESTION:

• could these 2 codes be related in any way?
• how can i troubleshoot the transmission?
• im afraid if i do a fluid change it could potentially get worse... is there any indicators to look out for that might let me know?
• would using the lucas stop slip additive help?

i really hope this thread can help myself and others with this problem
thanks to all!

 

I don't think that the two codes can be directly related. One is for the transmission and the other for the catalytic converter.

I am not so familiar with the automatic transmissions, but there may be some tests you can try to diagnose the P0740 code.

It sounds to me like the transmission is on its way out.

 

P0740 means the TCU has detected slippage between engine and final drive (torque converter not locking). Manuals usually recommend replacing the lockup solenoid, and see if code returns. If it does, it says to replace the transmission (internal hydraulic fault).

I'm driving a 97 Acura 2.5TL that has had P0740 for quite some time. I removed and examined the lockup solenoid (it was in good shape and actuated fine w/ 12V). I reinstalled and system was unchanged. I concluded there was a problem w/ torque converter and kept driving since car runs/shifts fine in other respects.

In your case, this problem may be just another symptom of general transmission failure.

What to do?

I would suggest going for a rebuilt transmission. Check ebay for some reasonably priced rebuilds w/ good feedback rating (99%+). I saw some for another party w/ this problem for about $1000. Installation will probably cost about that amount, maybe a bit less.

You could ask Honda for some consideration and see what they say. I've heard of some cases where they offer to pay 50% of cost, but this still runs $1500 or so, but maybe better than a rebuild and quality is near certain.

good luck

 

Thank you very much TEXASHONDA your post is very informative....

I checked the codes last night and i still get the same two codes as before ( P0740 & P0420)

now heres the thing that bothers me... i cleared the codes and the car ran like it didnt have any problems. now im just watching out for a TC slip then for the CHECK ENG light to come back on. could this mean it is an electrical problem?

 

I had a similar experience w/ VSS on this 97 Acura TL. When code was displayed, the vehicle shift (1-2) was horrible unless you let up on the gas, but shifted OK when VSS was working (intermittent).

It may be worth a try to replace the lockup soleoid and see if that fixes the problem. I'm guessing it won't but I've been wrong before. You may consider just removing LU solenoid, checking solenoid, and sealing surfaces. Solenoid is supposed to open to cause lockup and close to prevent lockup. My understanding of the nature of P0740 is that the problem is hydraulic, not electrical. However, I have heard of defective LU solenoid w/ damaged sealing surface.

good luck

 

sorry for the long awaited results.

well i found out the ohms/volts on the tcc solenoid and used a multimeter to see if it was working. bad news for me... it read out fine. so now im thinking ill have to replace the transmission.
i went to the honda dealership again to see what advise they could give me and yet again, i got a diffrent answer to my transmission problem. i decided that doing a fluid change could go either way. since my only other altenitave was to replace the trans, ... WTF it couldnt hurt, i have a 50-50 shot...
so i went to the shop and pulled the drain plug out. there was gunk on the magnet, but no metal shavings or chunks. after the fluid drained out i looked in the pan for metal but i only saw just a few shavings and the fluid smelled burned. i guess that would be expeted from not servicing the trans for 74K miles. all indications looking good so far. i put 4 new qt's back in and lowered the car.
immediatly when i drove away i could feel a diference. i drove about 600 miles to visit family over the holidays and 600 miles back. since the fluid change i have put about 2K miles on it and have had no problems. it did slip on me once but i think that was because it was 30 degreees outside and i did not let it warm up.

 

thank god i did not have to replace the transmission before the holidays.

i cleared the codes and so far, i have not had the code come back. the CHECK ENG light came on but thats because i need a new 02 sensor or a CAT...

... to those out there with trans problems, i hope this thread helps you.

what did i learn? ... CHECK YOUR FLUID! if it dosent smell clean, do a fluid change... if you do a fluid change and theres metal chunks chips or shavings and the old fluid looks metalic, the clutch discs in the transmission are probably falling apart.

good luck!

 

what did i learn? ... CHECK YOUR FLUID! if it dosent smell clean, do a fluid change... if you do a fluid change and theres metal chunks chips or shavings and the old fluid looks metalic, the clutch discs in the transmission are probably falling apart.

good luck![/quote]


if it smells burned... not clean

 

Thanks for the followup.

You may want to consider 1-2 additional fluid replacements to remove as much of old fluid as possible.

What ATF did you use?

good luck

 

ahhh... i went with the honda ATF Z1 fluid. i could have chanced it and went with some general fluid from autozone but i didnt want to chance it since there was such high miles, the uncertianty of it working or not, and ATF Z1 is the only fluid that will work correctly with honda transmissions.

i think another change in the fluid will do some good... probably drive better then when i bought it it hope.