1999 Honda Accord EX V6 Transmission problem
 

This is the deal. Transmission fluid was a little low so I visited friendly auto parts store. Worker advised me that with the amount of miles 200,000+ that Castrol high mileage transmission fluid is what is needed. Purchased and added. No problems. Next day topped off with gas and went to work. Check engine light comes on. Decided to finish work and check out problem later or see if light goes off. After a few hours light doesnt go off stays on and car starts to shift roughtly. Thought to myself maybe its the mix of old and new fluid. So the next day i visit same auto parts store and purchase same tranny fluid and drain and refill. Shifts out fine for a few miles and starts back again with same rough shifts. Do some research online and realize that Honda recommends only their tranny fluid. Dude gave me not only non import fluid but one not recommended by manufacturer. Two days ago went to Honda dealer "As i should have in the first place" and purchase atf z1 fluid flush and drain. The whole time durind all this the check engine light stays on. Car shifts out fine for first couple of miles and starts the same thing allover again. Now sometimes reverse doesn't want to work all the time only some of the time. Now friends are telling me that the wrong fluid recommended by the auto parts store person could still be in the system and that a total flush should be attempted. Is this a good idea or not even worth the trouble and start saving for a new transmission. I also heard a weak alternator could also hinder transmission performance. Keep in mind none of these problems were here before adding a half a quart of the Castrol high mileage transmission fluid. Care was taken with reguard not to overfill. Please help.

At this point in this drama, a flush will probably do no more damage, and may yet help.
Although there's still the issue of the "Check Engine" lamp and it's associated DTC. It is a possibility that a shift solenoid could have failed, but without pulling the code - any recommendation would be a guess.
Your ECM actually functions as two control computers. Both the Engine Control Module and The Transmission Control Module were incorporated for the 1998 Model Year.
If you have an AutoZone near you (I affectionately refer to them as DeathZone), they will scan the system for you and supply the codes available.
Honda had both a TSB and an extended Warranty Program involving Accord and Odessey Transmissions - but I believe it was limited.
Let's start with the codes first.

P

trans is most likely dead and no the trans fluid you added didn't kill it

I just had did a check engine light test.
P0171 UPSTREAM OXYGEN SENSER
P0301 CYLINDER MISSFIRE
P1738 MANUFACTURER. CONTROL TRANSMISSION
P0730 GEAR RATIO INCORRECT.
MAKES ME WANT TO CRY.

As I answered in your PM
Perhaps this will help:

Shift quality complaints such as harsh or late upshifts and downshifts don t always mean you need to replace the A/T. They're often caused by the 2nd and 3rd clutch pressure switch circuits being open or shorted to ground.

To confirm the problem, connect the PGM Tester, and check if DTC P1738 (problem in 2nd clutch pressure switch) or DTC P1739 (problem in 3rd clutch pressure switch) is set. These two DTCs do not cause the D4 indicator to blink and do not cause the MIL to come on.

the circuits refer to the electrical circuits, not the hydraulic circuits

the second gear pressure switch is near the oil fill hole plug and is screwed into the case perpendicular to the direction of the fill plug.

The third gear clutch pressure switch is directly behind the dipstick for the transmission. if you are to look at the transmission case through the dipstick you would see the connector for the 3rd gear pressure switch
hope that helps.

P

Re: 1999 Honda Accord EX V6 Transmission problem
 

hey p_adams
I have gotten the same p1739 code on my car and also had p0740 tcc circuit malfunction
and the p0730 gear ratio incorrect

what should i do about that and what can i do to fix the 1739 and0730 on my own as i do not have money to pay to get it fixed and need my car to make money now if could help here would greatly appreciate it

Re: 1999 Honda Accord EX V6 Transmission problem
 

Time for a 6spd swap ;)

Re: 1999 Honda Accord EX V6 Transmission problem
 

can you give me info i need for getting the 6 spd tranny to swap and where all can i find it cause was about to go with $100 fix and if messed up again was going to swap over to straight shift if could let me know would greatly appreciate it trying to fix this asap has been down since i posted on here

Re: 1999 Honda Accord EX V6 Transmission problem
 

Hey, can someone please help me. My check engine light came on and I'm getting the codes P1738 and P1739. Does this mean I have to replace the trasnsmission computer or is the tranmission itself messed up.

Re: 1999 Honda Accord EX V6 Transmission problem
 

[I am having the same problemswith my car right now, it's a 99 honda accord v6 i started experiencing the transmission slipping after i change my transmission oil and also the idling problem. First the check engine light came on and when i take it to the mechanic shop he put the machine on the car to read the code and the code was Po740.the car was change fine and they was no idling ,it was driving fine.now its not.please help.

Re: 1999 Honda Accord EX V6 Transmission problem
 

P0740 is not easily diagnosed by the home mechanic. You would need a few spare clutch lockup shift solenoids in known good order and a transmission pressure gauge to check pressures. Check around with a few reputable transmission shops for proper diagnostics.

Re: 1999 Honda Accord EX V6 Transmission problem
 

I know it's a old post but I also recently got a p1738. If you can can you post a pic of where this switch is

Re: 1999 Honda Accord EX V6 Transmission problem
 

98-2002 Honda Accord has J30A engine and all transmissions for Accord have problems. I had to buy one from Engine World Inc in Houston last year. It was a JDM transmission. Problem is they work well only with Honda Transmission fluid. Plus every time you buy a tranny the torque convertor must be reconditioned. These are very difficult to fix.

Re: 1999 Honda Accord EX V6 Transmission problem
 

Hey I'm having the same codes show on my Accord. Did you ever get it fix? If so what did you do?