Hello forum,

I described this problem a short time ago in the introductions forum, but I hope this is the place where I'll get some sound advice.

My wife's mom gave us her 2000 Accord V6 recently to drive around, since she no longer drives and the car has been languishing in her garage. We took the car out west several years ago and it drove great, but now it downshifts abruptly into second. I also noticed while changing the transmission fluid that the trans engages roughly when moving the gear selector into D2. I have not noticed any flare, and the transmission seems to shift up normally from 1st to 2nd.

The D4 light in the cluster does not illuminate at all -- I suspect the bulb is burned out.

I've checked codes with my Scangauge II and only get a 1457 emissions code.

As I mentioned previously, I did change the ATF using Honda fluid. The stuff I drained was dirty but didn't smell burnt.

I plan to do another drain-and-fill after I drive around a bit. I was thinking about a 1,000-mile interval. Hoping the fresh fluid loosens up any clogs.

But if not, are there any specific solenoids I can pull and clean up to try to restore the shifts? I suspect there may be some deposits from the car's inactivity. It's been driven maybe 1K miles per year for the last five years.

Thanks in advance for your thoughts.

 

There may be junk in the shift solenoids, there also may be junk on the 2nd gear pressure solenoid located on top of the bellhousing. Check that the wiring is not damaged or the sensor is not leaking. If you beleive there may be varnish or gunk build up, add a pint of Sea Foam Trans Tune help break up and remove any buildup while draining.

 

Thanks for your reply. Is the solenoid you're referring to part No. 28200-P0Z-003? Looks like there's also a filter, part No. 28220-P0Z-003. If so, they look like they should be accessible without too much trouble.

 

No.
28600-P7Z-003 is the pressure switch. #14 in the below image. IIRC upper unit near bellhousing is for 2nd gear, lower one near the left side cover is for 3rd gear.

28200-P0Z-003 is the converter lockup solenoids, not what you want to look into for the 2nd gear issue.

 

OK, I see it, just aft of the lockup solenoids on the bell housing.

Thanks again.

 

I examined the pressure switch, and it looked clean. No leakage, and the wiring looked sound. Hope the fresh fluid (and Seafoam Trans Tune) does the trick.

I will follow up with a post on results.

 

Shift solenoids also have screens, #12 and #13.
I don't think there is a VSS sensor on these transmissions, if this is true then the PCM probably relies on the magnetic pickups #15, for down shifting as well as upshifting. Pull these out and verify there is no junk stuck to the ends of the magnets, clean them and reinsert.

Any engine issues will affect how the PCM commands the transmission to shift.
Clear or fix the 1457 code and see if the shifting improves.

 

Good idea on cleaning the pickups. I'll give it a try.

 

Just following up -- shifting has smoothed out quite a bit. I changed the fluid a couple times, but I think the more significant effect came from a spark plug change. I pulled the plats that were in the engine and put in some NGK copper cores, ZFR5F-11s.

Looking back, the transmission was at its jerkiest when it shifted up with the engine under load (like with the car going uphill) at low revs. Perhaps a hotter spark has made a difference.

 

Yeop, engine struggles, so you feel this struggle but it's easy to blame the transmission. PCM does it's best to make the car do what you want, but if components are worn/busted it can only do so much to compensate.

FWIW, if you really want to have a better spark, switch to Denso Iridium TT plugs. ~$6-8/plug but they will last for over 100K miles and give you the best combustion.

 

Yeah, it's natural to suspect the transmission first when the shifting is rough. but other systems come into play. Not that the transmission is perfect -- it still engages noticeably harder when shifting into D2 than it does when moving the selector into D4, D3 or D1.

I thought about going to iridiums. The owner's manual specifies the conventional plugs, though, and I have mixed feelings about the array of super-duper spark plugs out there. I accept that platinum and iridium plugs have better longevity than the conventional ones, but do they exceed or even match the performance of conventional plugs? Not so sure about that.

Copper Spark Plugs vs. Iridium and Platinum: Understand for Top Performance