Something to check on higher mileage Pilot transmissions ( Code P0730 )

[jmbauer]

I have a 2003 Pilot with 160K miles on it. In the last say 5K miles it has started developing this problem where I get this RPM surge when shifting. More specifically I think the surge is occuring on 2nd gear to 3rd gear upshifts going up a slight to moderate incline. I have also occassionally noticed some strange downshift behaviour. The RPMs will surge and I can let off and the car will eventually shift and continue on. About two weeks ago, the check engine light came on (no flashing D). The code it was putting out was P0730 which basically refers to a problem with the shift control. To add to the mystery, the problem has not really occurred much in the past week.

I did some searching on the forum and it seemed that most folks that got a P0730 or had similiar symptoms ended up having to replace the transmission. I also found a page from the service manual about diagnosing a P0730. It basically seemed to say use a pressure guage set to check transmission pressures. If the pressures are good, then change all the solenoids. If the problem still persists then change the transmission.

Anyways, last night I ended up taking a look at the solenoids I guess for kicks and giggles. There are 3 shift solenoids A, B, & C and three clutch solenoids A, B, & C. I tested the resistence of shift solenoids A & C and got 17.2 ohms which is between what the spec calls for ( 12-25 ohms ). I overlooked solenoid B by mistake. I measured the clutch pressure control solenoids and got 6.2 ohms (spec is 3-10 ohms). I also energized each solenoid and made sure I heard a solid click.

At this point, I ended up removing an assembly which included the A & B clutch pressure control assemblies. Everything looked fine in there including the mesh filter screen. It looked completely clear.



So then I remove the clutch pressure control C solenoid assembly. This is located on the front of the transmission, near the starter. Here is where it gets interesting. The filter screen in this assembly was totally clogged. I don't know how any fluid would be getting past the screen. There was literally a solid coating of metallic particles that was 1/16 inch thick. See below.



I cleaned the filter screen by first reverse flushing it with compressed air and then cleaning the rest of the surface. Then I cleaned the sealing surfaced and reattaced it and reassembled the car. I feel pretty good that this may be the problem, but unfortunately I feel like I need to drive the car for about a month and have the problem not occur at all. I did take the car for a quick spin last night and the problem did not occur, but that's not really a good indicator.

Anyone else having transmission problems may want to look into cleaning this screen. We have owned this pilot since new and changed the transmission pretty regularly (tried to stick to the 30K schedule, but may have gone to 40K every now and then). Even if you are not having transmission problems and you have higher mileage, this may be worth looking at. I spent about 2 hours last night doing this.......if it saves me a transmission replacement it will be time well spent. Here are where the parts are located:

[dustino8]

Great info and thanks for posting. Bookmarked for future reference.

[Da Man]

Excellent detective work.

One question, though-upon reassembly, did you have to replace any gaskets etc?

[rocco686]

Has your problem returned yet?

I have replaced all pressure switches, but not the ones for the clutch. Nor have I checked the screen, but the Pilot does have a problem between 4th & 5th gear, constantly shifts up & down at 70-80 kph.

[samc]

jmbauer can you provide more detailed pictures of your work. I myself own an '06 and am reluctant to open up anything on the transmission until I see a problem. So I would like to see more detailed pictures/write up if possible.

But basically you're saying the clutch pressure control solenoid C which is right below the battery holder is where you found the single problem?

[sblvro]

did it correct the problem?

[playstrings]

Hey JM,

Great piece of detective work. Thanks for sharing.

[SD16]

This is a great site. My brother's Odyssey was presenting with these symptoms, and it was fortunate for him that I had read this thread a couple weeks ago. He had also had a MIL light on for several months. We cleaned the wire mesh on C, put it back together and started car - no MIL light. Time will tell but we think this trick resolved his issue, no shifting problems in the last couple of days. Thanks a bunch!

[rocco686]

jmbauer has the problem been corrected?

[Pilot_Driver]

Some info from an owner with an '04 with 170K miles. I checked the screen for clutch pressure control solenoid c and it was clean as a whistle, not one spec, but I wasn't having major issues, just a shudder under load at low speed in top gear, which was fixed by replacing the pressure switches for 3rd and 4th gear.

[Da Man]

Pilot_Driver-

Quick question-What seals this valve body to the transmission? Is there a gasket that needs to be pre-ordered, or is it sealed with an O-ring that is re-useable?

Thanks

[Pilot_Driver]

Originally Posted by Da Man

Pilot_Driver-

Quick question-What seals this valve body to the transmission? Is there a gasket that needs to be pre-ordered, or is it sealed with an O-ring that is re-useable?

Thanks

Its a rubber gasket type o-ring setup. I just reused the old gasket, but would have preferred to replace it if it hadn't been after hours at the dealer to get the gasket. I needed to close it up and have the vehicle again. But no leaks after 350 miles so far.

[Da Man]

I've looked on an online parts website but cannot identify the part. Have you had any luck with a part number? Appreciate it if you do for both of them...

[Da Man]

By part I meant the gasket.

[SD16]

A quick update on my brother's Odyssey. Turns out the problem was more than just a dirty screen, he had a rebuilt transmission installed last week. Dealer wanted 8K, he got it done for around $3700 at an independent shop. The rebuilt transmission was sourced from a shop that does work for Honda.

My brother drove his Odyssey hard, pulling a trailer in the mountains. He has a heavy foot and his van had 210,000 km on the clock at the time of the swap.

I'm keeping my transmission fluid clean, doing the full flush every 40,000 km, and keeping my fingers crossed. I'm going to check these screens as well.

Cheers,

Pete