About a week ago I was coasting along when the TL started to down shift quite early causing the RPMs to spike, it happened once or twice at that time so I pulled over to turn the car off and on again and haven't had the issue since.

I've paid close attention to how the tranny acts since then and havent really felt anything out of the ordinary. It's still peppy and kicks down pretty quick under throttle pressure with smooth shifts. Coasting is fine. In manual mode the shifts are decently quick and smooth (up and down) no different than they were when I first purchased the car at around 80k kms (50k miles).

When I first purchased the car (at 80k kms now at 104k kms) one of the first things I did was a 1x1 drain refill with Honda ATF-Z1... I'm paranoid now after reading around and learning I shouldnt have used that ATF. So thats why Im making this thread and wondering if I'm experiencing "slipping" or any other serious symptom as a result of a tranny problem.

I checked my ATF level and color.. from what I can tell it seems to be fine...




Any input/suggestions appreciated. I plan to change the ATF to something like RedLine (after some more homework) and changing the 3rd and 4th gear pressure switches very soon.

Cheers

 

I would get some RedLine in there. Either the D4 or the Type F should let you sleep at night.

 

Could you be more specific on the problem?

I don't think the ATF Z1 is contributing to your problem... if you even have one. ATF Z1 isn't terrible for your tranny IMO.

Also I think the car downshifts early if your going down a hill to help you slow down, but I am not 100% sure.

Now would be an excellent time for some preventative maintenance on your tranny... drain and fill, replace pressure switches as you mentioned. I have like 9 quarts of Acura ATF Z1 left so I will be sticking with that.

 

Will do. I want to avoid the harsh shifts by not having any FM (as with Type F irrc) so I guess I need to figure out what my best options are.


I wasnt on an incline or decline, just coasting straight (no throttle) and I was possibly breaking too. What happened was the tranny down shifted early (most likely from 4th into 3rd). Becuase it happened earlier than normal (speed or car was higher) the RPMs spiked and there was a jolt just as if you were to manually down shift into 3rd while in 4th (exact same experience) except the car did it on its own a little too early which caused the jolt and high rpms... Thats as specific as I can be

I'll be doing a bit more homework before deciding if I'm going to stick with Z1. All this friction modifier mumbo jumbo has perked my interest.

 

how high did the rpm jump after the downshift? for mine when im braking a bit hard, it would jump as high as 2.5k rpm

 

It was substantial.. at least for what Im used to.. I'd say it kicked down and hit between 2.5-3k.

Does this mean my transmission had "slipped" ?

 

For future reference for anyone who may stumble onto this thread, the fix is more than likely the transmission gear position sensor, part #28900-RDG-013. The sensor seems to short and the ECU doesn't know what gear its in so it downshifts into 3rd or lower if possible.

 

That sounds normal to me, especially if you tapped the brakes a couple of times. 2.5k in 4th gear is like 50mph; doesn't seem like a spike to me.

 

I can't believe this thread was replied to twice today. Today was the day that I started researching the dreaded blinking D light problem.

Lately during long trips, my D light will go out and my car will down-shift. After a few seconds the light will turn back on and it car will up-shift back into whatever gear it should be in. Shifts are still smooth and without noise - just random loss of the D light and sporadic shifting when that happens.


Again, just absolutely freaky that this thread was resurrected today as this is the day I picked to look all this stuff up and was contemplating creating a thread for it.

My plan of action is to replace the 3rd and 4th pressure switches and change the filter too along with a flush? In all honesty I'm not done reading so if anyone has any particular advice I'd really appreciate it.

Now I'm wondering about this gear position sensor.. I'll look into that too.. hopefully a DIY?

Cheers

EDIT: Didnt notice the reply was from Alex who I had PM'd earlier today about a similar problem he had.. hah! Thanks man.

 

I had the same exact symptoms and replacing the gear position sensor seems to have cured it (2 months so far and it hasn't happened since.)

The service manual I linked to you in a PM has instructions on how to DIY replace it, and states to do so if the D light isn't on. Enjoy

 

I wrote a thread about my blinking D light... It wouldn't let me shift past 3rd gear. I'll find it

 

Blinking =/= flickering. Sounds like a different problem.

 

^ Yeah not to confuse people... I don't know if I've witnessed the official 'blinking' D light issue.. I can only assume that's when it just sits there and blinks on and off for a period of time without being able to go into gear? If that's the case, it's not what I experienced.. Though if I recall correctly the light did blink on and off a few times on some occasions without changing gears.. But I'm mostly getting the light turning off, down-shift, light turning on, up-shift.

 

Were you able to access the .pdf?

 

Yup

 

sounds like the "grade logic" feature to me. the RPM spike will vary depending on your speed and % of road decline. Lot's of information available on this feature. Here is some from a simple google search.

Honda Transmissions and Grade Logic
Ok, after doing a few searches for "grade logic" and "disabling grade logic" I came across the following threads:

Rough Tranny Shifts
Shifting Ody Tranny Like A Manual
transmition slows down my van

and most importantly this tread:
Tranny gears down braking or coasting downhill - good feature?

I've decided to start a new thread on this topic for search reasons. I figured if this information was found under a tread with subject indicated as so…it would be better (provided people remember to “search” first)….Guilty as charged!!

1. A few people have asked the question "what exactly is grade logic"?
2. Is there a way to disable the grade logic?
3. Honda transmissions "learn" the way you drive...how do you "reset" them?

Now, I can answer the first question in layman’s terms, but I really think that there are other individuals on this forum who can answer this question succinctly, so I'll leave it up to them.

 

*waiting patiently for ihc to come in and educate*

 

ITS NORMAL

dont worry about it...and +1 on Z1 not being terrible for your transmissions....I ran Z1 for ~75K miles (upto 147K miles and it was just fine)....I have been running Redline since and am at 170K miles...

 

Grade Logic does not cause the Drive light to turn off, did you bother reading the last few posts I made... and if you read the service manual, it states that if the drive light turns off you should check and replace the transmission position sensor.