Maximax2

There have been varying opinions on this, but I can now confirm that the ECU flash didn't fix my 2k3 throttle lag. Just updated a previous post with this:

Did it cure the throttle lag I had? In previous posts, I noted that post-ECU flash the lag seemed a lot better, but gave the caveat that we'd had a cool front come through, and this problem is allegedly better in cooler weather. Sure enough, with 80+ outside the the lag is back in full force. Press the gas, and half a second later the car will start to react. Sigh. Still, in the scheme of things not a big problem.

>>>>>>>>Edit: New info. posted below:

Okay, after some semi-extensive testing last night and this morning, here's my new theory:

There IS no throttle lag (no, this is not a Thought Police joke). All of the other automatics I've driven have delivered linear acceleration from a stop, with no noticeable "lock-up". A curve like this:

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00000000000000000
00000000000000000000

The 2k3 auto transmission seems to work differently. At low throttle (less than 1/4), it moves off smoothly just as above. At anything over 1/4 throttle though, it starts slowly but then there's a sharp "bump" as the tranny seems to "lock", and acceleration jumps - something like this:

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0000000000
000000000000000
000000000000000000

So, to handle what's a pretty huge amount of torque for a FWD auto, did Nissan change the tranny design? Allowing the torque converter pressure to build up much more quickly if much power is applied - delivering more efficient acceleration? Bear in mind, other than reading about auto trannys in howstuffworks.com, I know very little about them. I'm curious enough to call Nissan, though, although it's unlikely they know / will answer...

Anyway, that's my new theory

Virus

iTrader: (1)

Maybe they didn't actually perform the update for you.

woosh

What someone should do is ask the tech doing the flash to show you the current ECU rev. Write it down.

After they do the update ask to see the new rev and write that down also. Then come back and make the org wiser.


SHIFT_woosh

swallac2

It's not to fix the "lag" that you speak of. It's to correct the hesitation. The hesitation is more like a lurch from what I have experienced. When you step into the gas the car isn't just slow to take off, it sometimes gives one little shutter.

Maximax2

I know, but some of the guys reported that it helped, so thought it was worth a try. In my case didn't hurt, and who knows - maybe it DID give us our 15 hp

FYI, I'd say that the dealership did do the flash - they've always been EXTREMELY helpful with problems. Also, they called me to let me know it was delayed 'cause they had to talk to Nissan (despite my telling them the flash procedure was different from the usual, they apparently had to talk to Nissan to find out "the procedure's different...")

realtor

The TSB cured my car and it runs better than new. I suggest that you SHIFT _to another dealer.

Maximax2

Did you have the hesitation or lag problem? What's the temp where you are? Good for you if the lag got fixed, but you may find it's wishful thinking like me...(hope not).

realtor

I had the hesitation for about half a second when accelerating from a complete stop. I'm in Tampa, FL and we are starting to hit the low to mid 80's in the afternoons.

Maximax2

Edited with new info. in the first post of the thread.

studman

I've had the TSB done, but can't tell you whether or not the 15 HP is added. I need to convert back to my WAI and then head to a dyno. If I see a 6 HP increase, then I know that it didn't add the "missing 15 HP" that we complain about. If I see a 21 HP increase, we'll have to take a look into the update.

The 6 HP increase will come from my UDP install, since I haven't dyno'd since it was installed.

And for the TSB side of it, I never really had the lag to begin with, so it's hard to tell whether or not it did any good.