sam12345

iTrader: (1)

I had all kinds of electrical problems with my car but the engine drive train worked perfect. My 0 to 60 times varied between 5.8 to 6.2 seconds (I'm at 3800 ft altitude). It turned out that my electrical problems were caused by me ECM and there is a service bulletin on it. So I bought a used ECM that is the revision that the service bulletin says. Fixed all my electrical problems but my 0 to 60 times now are 6.4 to 6.8 seconds. From my research there are no performance chips for this car (I think) and the ECM looked stock to me. So was there some software change or what? I want my 0.6 seconds back. Don't get me wrong the car still runs great but the power loss is noticeable even in the seat of the pants. Can anyone enlighten me?

shvc1991

Perhaps the ECU still needs to learn your driving habits?

RamAirRckt

The ECM's won't learn if you are driving heavy, drive normal and it will learn fairly quickly, each load cell, seconds. It doesn't take days to learn, and it is learning only the fuel trims.

Just drive normal, higher rpm, light load, lower rpm light load. the heavy load areas (WOT, etc) aren't learning modes, you can't, so it needs the other ranges and it will extrapolate from there.

Get some miles on it, drive city, highway, a little higher rpm stuff (say 70 mph in 4th for a short distance, say a mile, varying the load gently), etc. That will accelerate the learning, but else just drive it normally. When you nail it, no learning can take place.

GS4_Fiend

iTrader: (22)

Did you had to reflash the pcm? Or just plug and play?

sam12345

iTrader: (1)

Just plug and play. I already put 200 miles on it. How many miles does it take for the ECM to adjust?

GS4_Fiend

iTrader: (22)

Interesting, it should be reflashed regardless. That may fix ur issue.

sam12345

iTrader: (1)

I drove the car today and it felt like it use to at part throttle so I did another set of 0 to 60 runs (I use a scan gauge II ) and I got 6.0 to 6.4 seconds (using automatic mode) I noticed that the car would shift to third right at 58 mph and that before it would shift at around 63 mph I looked at the scan gauge and it's shifting at 5400 rpm before it would shift at 6030 rpm so the extra shift is probably worth the .2 seconds. I wonder if that will adjust with time. Well at least it's better. How do you reflash the ECM? Do you need the scanner?

1GSLuVeR

This is what i found:
https://www.clublexus.com/forums/gs-...u-flashed.html

GS4_Fiend

iTrader: (22)

Nice find, but that's to reflash the ecu for KEYS, not PCM.

GS4_Fiend

iTrader: (22)

To reflash the PCM, you would need to take it to the dealer, or an independent shop that has a software that can do so.

How did you figure out you got a bad PCM in the beginning? They don't go bad unless been tampered or flooded, even though it's in a sealed box.

sam12345

iTrader: (1)

I did some google searches and apparently it can take more than 500 miles for everything to adjust. The car seems to be closer and closer to how it was before the ecm change. I think I will wait a while and see what happens before going to the stealership. ( they would probably charge me more to reflash than what I paid for it, the cretins)

1GSLuVeR

Sorry, didnt realize it pertained just to the keys and not the ECM also..

GS4_Fiend

iTrader: (22)

report back if everything goes well. i doubt it will make a difference though, but worth trying.

sam12345

iTrader: (1)

When you floor it in auto mode at what speed does it shift into 3rd? If you have a scan gauge that would be better because the speedo can be 2 mph higher than actual speed. I was looking in YouTube and it seems they all shift a little shy of 60 (as does my car now) before it shifted a little passed 60 I am guessing that's the difference. For a 3800ft in altitude my car is probably near spec and before it was probably better than spec since 5.8 to 6 seconds at 3800'ft is what it is spec out for sea level.

sam12345

iTrader: (1)

Here is the answer to this question

https://www.clublexus.com/forums/gs-...al-issues.html