2003 Honda Odyssey: A warning code yesterday, but gone today...?

2003 Honda Odyssey 146k miles Yesterday, engine light on and mechanic #1 pulled Code 0730
Today, I took it to mechanic #2 and no codes.

Car has been basically great, but the last 3 months, about 5x driving at 30mph going to next gear, the engine will rev to 4k and almost stall - I’ve taken my foot off the gas, waited 5 seconds, and then it calms down and I can drive normally.

Lots of transmissions on these Odysseys fail around this mileage (146k).

Are codes appearing and then not appearing the next day …normal??

No mechanic has been able to duplicate my experience. Ah, the fun of owning an older car! But I love it and the great visibility of the 2003 model.

Have you had an actual transmission shop look at the vehicle ?


I agree that the OP needs to have a trans shop diagnose the problem, but I urge him/her to seek an independent trans shop that has been in business for several years. An accurate diagnosis from an indy shop is MUCH more likely than if he went to a chain-run joint, like Lee Myles, Cottman, Mr. Transmission, or AAMCO.

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A basic automatic transaxle/transmission is the most complicated, mechanically, part of a normal vehicle, then you start adding solenoid controlled valve body’s and also adding computers in the mix, now they are very complicated on multiple levels, and then Honda went and mixed it up and added another element to the mix and combined a manual transmission with an automatic transmission and now you have a transmission that even a lot of transmission builders don’t rebuild… Love them or hate them it is what it is…

I think you are WAY over your head trying to figure this out yourself, save yourself some headache, wasted time and take it to a qualified/reputable transmission shop and have it Properly diagnosed and or repaired…

A P0730 means that the computer picked up an incorrect Gear Ratio at some point, that means for whatever and or for many possible different reasons your computer sees a RPM (speed in rotation of the shafts) difference between the transmission input speed sensor and output speed sensor that is greater than a certain value, meaning it is flashing or better known as slipping…

If a reman transmission is installed from a quality builder (Jasper, etc, not local parts house), it should have all the updates and should last a very long time and many more miles…


Thanks for the tips. Alas, I live in a smallish town where there are really only 2 good mechanics - and both of them are baffled! And both, according to longtime locals, are very good at transmissions. I wish one of them would just go ahead and replace the transmission, even though it’s expensive. It’s cheaper than renting a car.

I went to two good local mechanics who do lots of transmission replacements and rebuilds (no purely transmissions shops anywhere around here).

Check other smallish towns or bigger towns, a tow is cheaper than a rental also, depending on how long you are renting for…

Have you given them the green light to do it or are they scared to work on it… Again, a lot of builders/trans shops only R&R them, hard to find someone willing to build one… Jasper would be a good bet for one…


Only 2 mechanics and this person has been going to both for the same problems. I am going to guess that they know each other and help each other at times. They just may not want to mess with this person and a old van.

AAMCO = All Automatics Must Come Out

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I’m not in a big town either but I drive 40 miles for transmission work. Even towed a car there.

Now I had a car that would neutral out from 1 to 2 forb10-15 seconds, then catch. Same place each time, but only when the weather was hot. Had been overhauled some time prior but they don’t replace every part. Never found out exactly what it was.

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Is your car still running well?

Two good ones and I’ve gone to both when one doesn’t have an appointment available- they’re both always busy and VERY helpful always.

It seems to me that if the van threw a code it would be stored even if the condition didn’t exist when the Odyssey was scanned the second time.

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Weird, huh?

I shot it a dozen years ago with 520,000 just to put me out of its misery.

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520k!!? Wow! But mine only has 146k.

Did the first mechanic erase the faults?

Do you mean did he fix the problem? (Sorry, don’t understand your question)

After viewing the transmission control module faults, the technician has the option of erasing the faults. If the faults have been erased, technician # 2 can’t view them. The fault(s) will be recorded again when the next failure is detected.


Thanks for explaining, I’m not sure - I’ll ask. He dis something to make the engine light go off.