Shift points changed?

[veloman]

There is this small downhill after a stop sign that I ride every day. A few months ago I would always get a shift into 4th gear at 32mph. I never get that same shift anymore? I keep the same throttle as I always did, I never can get that shift. Is there some "AI" computer that adjusts when my car shifts according to my driving habits?

It's a 97 Civic ex

Also, when I first got my car from the 1st owner a year ago, it would downshift out of overdrive on a certain hill on the highway. After a week or two it completely stopped doing that. Perhaps adjusting to my driving style?

Weird

I just hope there isn't something going on in my transmission. I checked the fluid and it's fine. I had a complete tune up down a year ago as well.

Sometimes I just want to trade my auto for a manual. But I really hate the idea of a stick when I'm in traffic.

[bobski]

It's probably just adapting. With the '96 model year, Honda added components to the Civic's automatic trans that give the ECU much more direct control over the transmission. In addition to typical control programming, the ECU got "Grade Logic Control" which is supposed to help with ascending and decending inclines in the D4 shift position.
Here's the basic service manual info:

[Hockey4mnhs]

Do you know if my car 93 accord has the same learning software?

[veloman]

Wow, I never thought it was that advanced and complicated! Thanks.

[bobski]

Originally Posted by Hockey4mnhs

Do you know if my car 93 accord has the same learning software?

I only have the manual for the '93 CC7... I don't see anything about grade logic or other adaptive control. The '94 Accord CD7/CD9 appears to have been equipped with grade logic in some regions.
Looks like you missed it by a year. The wiring diagrams for the two transmission computers look nearly identical. The grade logic TCM gets an atmospheric pressure signal, and outputs an interlock control unit signal that the non-grade logic TCM lacks. Maybe you could upgrade?

[Hockey4mnhs]

HMMM i might look into that thanks for the info

[LastBoyScout]

could be that you just need to re-teach the ECU your driving style. I was able to get my ECU to tweak the autotrans down to 2k rpms for the shift points if im easy on the gas. I can hit 4th gear at 35 mph with no problems.

Just clear out the ECU by disconnecting both of the battery cables and then touch them together or ground them both out on the car. Then just let it sit for 10 minutes or so to let any residual energy discharge and the memory to clear. Hook all that back up and with the car and engine completely cold start it up and let it sit and idle with no accessories turned on until the car warms up and kicks the engine fan on. Shut off the car. This should give the ECU a chance to learn all the current enviromental settings such as ambient air temperature, any mods to the car such as air intake, ect ect. Once the car has cooled back off, take it out for a spin and drive it like your grandmother stole it... err... for FE. the slower you get up to speed the lower it will try and shift to the next gear (within reason and limits of your ECU programming). Do this till you hit the normal operating temps and then drive for about 10 more minutes. After this, just keep up those normal driving habits for about the first 50 - 100 miles.

its well worth it assuming your ECU can handle it. Gotta love Honda/Acura

[shatto]

Hah! My Tundra would be in 5th at 32 MPH.



But it wouldn't get as good mileage as you.

[GasSaverTips]

Thats an intriguing idea. I will look into that.
http://www.GasSaverTips.net

[theholycow]

Originally Posted by GasSaverTips

Thats an intriguing idea. I will look into that.
http://www.GasSaverTips.net

Jay said it well in another thread...

Originally Posted by Jay2TheRescue

We're not interested in paying for your report, only to find out its nothing we don't already know. Thanks for stopping by and dropping your link though, you're probably the 5th or 6th today.

-Jay

[Jay2TheRescue]

Thanks HC, I feel special...

-Jay

[bobc455]

I couldn't see what is posted above.

But, some transmissions will keep you out of OD (less common), or keep the torque converter unlocked (more common), until a certain engine temp is reached.

Is your engine always hot when you reach this hill?

-BC

[PaleMelanesian]

You might try shifting to neutral and then right back into D. I can get my 2004 Odyssey into 5th at 41mph instead of 45 by doing this.