Is a transmission ecu upgrade/mod available anywhere? The way this transmission shifts is a crying shame for anyone wanting performance – especially downshifts. I guess it’s fine for a lot of folks but I get pissed everytime I stab it and the transmission goes through something like this:

OK, HE WANTS TO GO FAST – START DOWNSHIFT SEQUENCE - PROHIBIT ENGINE REV INCREASE - RELEASE ONE BAND – ROUTE OIL PRESSURE THROUGH PASSAGE G, PAUSE n MILLISECONDS (DON’T WANT TO RUSH ANYTHING) – PAUSE FINISHED – RE-ROUTE OIL PRESSURE TO PASSAGE h, CLAMP DOWN ANOTHER (LOWER GEAR) BAND – NOW ALLOW ENGINE TO INCREASE REVS – PAUSE AGAIN (MAKE SURE THAT THE SHIFT ISN’T TOO “ROUGH”) – THAT OUGHT TO BE LONG ENOUGH – GUESS IT’S TIME TO RETURN THE GS TO GO FAST MODE – RELEASE (BUT BE CAREFUL, NOT TOO ROUGH)]

It’s a damn shame that we don’t have a six-speed option or at least an ecu that will improve performance at the expense of smooth shifting. I’ve got a few hundred dollars burning a hole in my pocket that’s ear-marked for such a mod. Listening SRT, Weapon, RMM, L-Tuned, TRD, etc.??

 

Yeah - there is a TSB that you may be able to convince your dealer to perform for you. I've had it done, but I don't have the TSB number handy. It basically should lessen the hesitation. It did on my stock transmission. But, I soon thereafter got the SRT/PI TC installed, so its even less of an issue.

 

Can you please find out the TSB number that was done on your car and post it.

 

The TSB was not listed on the invoice - just the name and part number of what was replaced and some other number. I will post them later.

 

The TSB for the GS hesitantion is for 98 GS's only. I had it done to my old GS (98 GS4) and the biggest difference was in e-shifting, it shifted faster into the gears, otherwise it didn't make a big difference. I just looked over my service statements from the dealership and it said they ordered the part and would call when it arrived. I have no receipt of the part # or TSB #, sorry. Dex says he has the info, so I am sure he will post it.

 

Garnet,

Install the TC and your GS will be a total different beast. The higher slipage rate will make your GS downshift more frequent and rapid.

Next time I go Dallas meet, I can let you try it out on my car, you'll see the difference

 

GS430 GUY – you indicated that it was for ’98 GS’s only – was that intended to exclude ‘99 models? I know that’s what you said but wonder if it was a general statement excluding your current 430, or was the TSB specifically to address something on the ’98 only? Just want to know whether it’s worth checking the dealership for my ’99 or not?

Jacob – thanks for the offer – I’ve been aware of the improvement in getting off the line but wasn’t aware of the other benefits, like the faster downshifts, etc. How is wheelspin with the 18’s if you floor it from a dead stop? I’m looking forward to going to 18’s around mid-year after I decide on the wheels – maybe the TC is worth putting in first? About how much would I expect to pay for install – any idea? Thanks!

 

When I had my 98 GS4, it was for the 98 models only from what I remember when I had it done. If memory serves me correct some members on the old clublexus board had 99's and complained loud enough to get the ECU swap but the dealerships were very stubborn to do it. The upgrade was for 98's only b/c supposedly the fix was done on 99+ at the factory before they hit the shores. As for my 430, it's not even part of this, I went aftermarket and got a TC as Jacob recommended, my car downshifts a lot faster now. Hope this helps. Anymore questions let em fly.

 

---------------------------------------------------------------------
PRIME ITEM

895011 ENGINE CONTROL MODULE


PART NUMBER
8966630050 COMPUTER, ENGINE CON

CONDITION HESITIATION WHEN ACCELERATING
CAUSE ECU
REMEDY R&R ECU WITH UPGRADE ACCORDING TO TSB

---------------------------------------------------------------------

This is how it is printed on the invoice - sorry, no scanner, unless someone wants me to fax it to them, they can scan it, then post.

I think it is for 98s only too. When I had the work done, the service rep talked also used the term "service campaigns".


HTH

 

Garnet,

You just got started now

The TC unit is around $800. The installation will be 6 hours of labor ~ $400. YES. You'll get a lot of wheel spin if you floor it from a dead stop, that's why I got the LSD right after the TC

 

Hey DEX how much did that part set you back! How much did it cost installed !!!!!!!!!

 

$0

 

Hey Guys,

Basically my 98 GS400 is bone stock. I notice that there is a very big lag when full throttling the car when in motion. There is a huge herkey jerkey lag before the engine and trasmission get into sync and than take off.
I am relatively new to this club and not sure what TSB stands for. Is that something the dealer performs under warranty. My car is still under full factory warranty from lexus. Should I look into getting a l-tuned ecu, can anyone explain me the difference or what I should do.

Thanks,
Drew

 

Leave the car in M4 (or M3 ) - you'll find it more responsive. Power mode helps too.

The kickdown is VERY slow when it's in 5th, which it goes to far too easily.

 

TSB is for Technical Service Bulletin, released by car manufacturers to their dealerships, and best done under warranty. The L-Tuned ECU is for steering only, not for tranny nor engine.