[az_ronnie]

Hi everyone,
I own a 2001 Honda Odyssey with 67,000 miles. I have the factory manual and a code reader. The MIL, or check engine light, turned on a few months ago and I discovered a trouble code (P0 740) which is is the torque converter clutch solenoid circuit code. I drove the car thinking if the code was valid I'd notice a problem with converter lock-up. The only problem displayed by the transmission was a delayed 1/2 upshift -- accelerate at any rate other than slowly, and the transmission refuses to shift until 3500 to 4000 RPM is reached. From that point on, the transmission performs normally, including lock-up. At least it appears to be locking up -- engine RPM at highway speeds seems normal. Finding no problem with converter lock-up, I erased the code. I did have to replace all motor mounts, however. The engine was flopping around like a fish out of water--apparently a common problem with Hondas.
Not much later, the check engine light came on again, and the same trouble code is displayed on my reader. I read the Honda service manual section pertaining to checking the Torque Converter Clutch Solenoid Valve-Shift Solenoid Valve A, and it checks OK. Going back to the manual, I reread the section pertaining to diagnostics procedures following display of the DTC 740 code and it says to check the transmission line pressure -- before doing much of anything else. Checking line pressure requires about five pressure gages, jacking the car off the ground, and running it through an acceleration sequence during which you are to record the pressures of the various clutch circuits. The manual advises that the transmission is to be replaced if any of the line pressures are found to be low. Elsewhere in the manual, it advises to check the converter O-ring and install a new one if it's found to be missing or bad. If it looks okay, we're back to replacing the transmission.
At this point, I'm wondering what to do next. I suppose the line-pressure test is feasible, but I'll have to buy the gages and adapt them to do the test. I don't want to go to that trouble, if it's likely the transmission will have to be replaced anyway. Does anyone know if the DTC 740 code is triggered when the line pressure is low? It seems logical that some other sensor would report a pressure problem and that the DTC 740 code would pertain specifically to the torque converter clutch solenoid. Any suggestions? Thanks for any help in advance...

Ron in Chandler, AZ

[biff26]

Code P0740 can be from low line pressure, but usually due to the friction material coming apart and plugging internal passages. The transmission has an internal filter but debris can get past it. P0740 can also be set due to slipping torque converter clutch (PCM compares inputshaft speed to outputshaft speed and can set the code for as little as 50 rpm variation). Due to my past experiences after changing solenoids and a few converters which seem to be A short term fix if you are planning to keep the van for awhile transmission replacement is your best bet. Honda has made many updates to this transmission over the years.

[az_ronnie]

Code P0740 can be from low line pressure, but usually due to the friction material coming apart and plugging internal passages. The transmission has an internal filter but debris can get past it. P0740 can also be set due to slipping torque converter clutch (PCM compares inputshaft speed to outputshaft speed and can set the code for as little as 50 rpm variation). Due to my past experiences after changing solenoids and a few converters which seem to be A short term fix if you are planning to keep the van for awhile transmission replacement is your best bet. Honda has made many updates to this transmission over the years.

Thanks for the information -- that's exactly the input I was looking for. Looks like I'm going to be "biting the bullet" and replacing the transmission. I think we're at the point where we should be thinking about going to a newer vehicle, but, ethically, I can't pass along the problem to someone else. Thanks again...