As you know, if a failed auto tranny is replaced by Acura so is the ECU. I suspect the "new" ECU is designed to reduce the stress on the new tranny by effectively detuning the car (e.g. less agressive shift pattern, lower rpm shift points under WOT, timing changes at shift points to reduce engine power etc.). For those who have had their tranny/ECU replaced have you noticed a drop in performance, especially if you are modified w/headers, S/C etc ?
Thanks.

 

Yes, my car does not want to downshift at all!

 

just got my car back today yes big differance, it shifts at 6 instead of 7 rpm at wot,it also used to chirp second but now it does not it kinda sucks give me back my old ecm my car is stock so every bit is helpfull i wounder how much power is lost,i talked to the shop manager he said they did it because there was too much tourqe thats why it shifts sooner hopefully thats all

 

Anyone else had this experience ? I am very interested in your inputs since my cl-s is heavily modified (yes, I have the Comptech S/C, headers, exhaust etc.) and my tranny is sticking sometimes in 2nd at WOT. However, I am NOT comfortable with Acura forcing me to replace my ECU if the tranny is replaced. That would be like accepting a 4-cylinder engine to replace our V-6 if that were to be recalled! Comments please. Thanks.

 

Too much tourqe??!! Damn, our cars have shit for tourqe! Honda just cannot design a decent tranny. As for the power loss, I get my car w/ new tranny back next week, already getting set to go bitch to the dealer if there is an issue. Couldn't Honda/Acura be sued if the swapped ECU and you ended w/ less power? It's like giving you back a lesser car than you paid for.

 

Dont think they can be sued..........Im sure the engine still has 260 HP like when it started

I just picked up a new TL (yes, I know, it has 2 too many doors) and am interested in this issue. According to everything Ive seen they "fixed" the issue, but when I read real-world accounts it looks like its STILL not fixed. Ashame.

I also went thru the tranny replacement thing with my 2000 Accord...........people complain about losing a tranny at 20K miles. Guess when I lost it in my Accord? 1500 (yes, fifteen hundred) miles. I had the car for a month before it died. Granted, it wasnt a 5spd auto, but I think the issue is the same.

On the other hand, I dont think expecting the tranny to work forever if you rev it up to 7K to shift is a reasonable expectation. Everything has its limits.

I heard a rumor once that Honda was going to team up with GM to make drivetrains.......Honda provides engines, GM provides trannies. Imagine that..........the best engines hooked up to some of the best transmissions (the GM 4-spd auto used for the Pontiac GTP is as close to bulletproof as you can get).

-Chris

 

Eh, fuck it. I'm gonna buy a 05 Cobra Mustang, and drive this slush box until then...

 

my tranny and ecu just got replaced and my service manager said that it is not a detuned ECU at all - all the shift points are the same and the performance is the same. soooo.... i dunno. i get it tomorrow, i let u know

 

hell yeah! The new mustang's gonna be great...

 

i had my tranny replaced last week. it was the forth time i brought it to acura with complaints and finally they decided to replace it. i had 67k miles on my '01 cl-s. i got it back yesterday. very surprised at the power loss. i used to chirp 2nd now i can't feel the car shift at all. is there a shift kit or some kind of tuning i can do to improve it? i am adding a tranny cooler this weekend to preserve the life.

 

The ECU has a 2-degree ignition retard added during shift transitions to keep the 3rd gear clutch pack from being toasted.

There is a possibility of having a lowered rev level in auto mode when the ATF is cold.

Let the car break-in and make sure it is warmed up before making any final conclusions -- OK?

You will find people that originally thought the car was slower (after the ECU + newest tranny replacement) and found out that it was just as fast or faster when run at the strip..

Chirping tires is not a good way of determining how fast the car is (long story).

BTW, there is also the possibility of getting a “dud” box (even a new one) or having some morons install the new one.

YMMV

 

after driving up north with my newly installed tranny and ecu, there are a few things i noticed.

1) when driving along at a fast speed (maybe 100mph+), if i push down more on the accelerator, it seems to downshift into 4th more readily than it had before... with my old tranny/ecu, i would push down more, and it would just stay in 5th until i floored it... (and sometimes even then, it would just stay in 5th)

2) when accelerating at a fast speed (maybe from 80-120), there are points where my car will move into a lower gear for about 1/2 a second, and then move back to a higher gear... it almost sounds like the tranny is slipping for 1/2 a second, but i do feel it engage momentarily at the lower gear...

3) my tranny still shifts at redline with WOT (and car warmed up)

the "erratic" shifting (1) is really the only thing that worries me... perhaps i got another bad tranny

 

Ya, I run the same times when it's cold. Only dislike is to achieve the same times I have to gate shift now, and the car can't be warm... In D5 or man-u-shift mode it's still cheezy. I'd prefer the older ECU... Funny if it's cold I can get them to chirp if I shift at 6k. Once it warms up, back to turdness...

Any ideas?

Anyone programmed their ECU? Be nice to tune it to my mods.

 

Strange....


The Acura docs showed in INCREASE in G force during the 2-3 shift in both cold and hot modes. The shift point for hot operation (fully warm with ATF around 90+ degree C) was very close to the original shift point.

The cold shift point has been lowered to keep the clutch packs from trashing themselves.

Have you gone to a track (with similar baro, temp, etc.) and actually gotten a 1/4 or 1/8th mile time? The ignition retard is only supposed to be used for the 2-3 transition to lower the heat produced (It would be like shifting a manual without lifting off the throttle -- not exactly great for the gearbox and clutch [OTOH, you will gain a bit of time if your racing for pink slips]. )

You're the one with the new box, but I've seen years and years of road tests comparos where someone said something akin to: "Car-X felt the fastest of our comparison cars, but were surprised when it came in last [or near to last] when we did our acceleration testing"


Unfortunately, the older ECU doesn't have the “MOD” to alter the hydraulic characteristics of the shift. The clutch pack mod is basically composed of: (1) different process/better Q/A of clutch friction surface, (2) change in shift mode to keep heat from climbing over 360 degrees C in their 2-3/3-2 shift repeat tests, and (3) change to shafts, etc to insure more ATF is pulling heat away from the clutch plates/disks. (More stuff too, but…)

In the new Honda Accord with “drive-by-wire”, they close the throttle plate during shifts.

Finally, one member said they HATED the way the new tranny felt, but disconnected the battery (for 20-30 minutes?) and changed his mind (I've been away, so this may have changed, but...)


AS for the ECU, I'm now as unsure as ever about the reprogramming issue! Is the problem due to the custom VLSI/"one-off" chip for Honda/Acura? Is the problem due to a lack of a flash programming connector (mentioned in Acura docs)? Or is it really true that the chip is a one-time-flash; or does Acura just have a small "access" sequence that enables a "re-flash"; and/or does Acura just "ZAP" the chip to prevent any further reprogramming of the core firmware? (I have no clue…)

It would be scary to find out that someone just didn't want to figure out the pin out and find a proper clamp on test clip/probe to allow full read/write of the chip...

 

Well, I'm sure the ECU has certain areas for flashing so that the DTC's can be cleared. And anyone with a CL service manual will be able to tell if the ECU can be reprogrammed upon removing the Accessory Back Up fuse or the battery cable.

And also, when people get a new tranny, they may want to wait until the tranny breaks in. I don't think many people drove their cars very hard when they first owned it, so why do that with a new tranny? Wait a half-thousand miles or so and then see how the ECU adapts to your driving habits. And with the changes in the new ECU, you'll probably notice that your car may shift differently than before, but at least your shifts will be consistent. That is, if your clutch packs and seals are holding in the new tranny.

 

i havent noticed decreased performance... but i have noticed that in just a few hundred miles the tranny is back to its harsh shifting ways :shakehd: