bad-gs400

I just finished installing the L-Tuned steering ECU. Pain in the a**! Only took down the ac panel above the pedals. The top panel was hung up on the right side (ignition). I could not find any location for screws to dis-assemble that panel. The bolt holding the ecu was tough to get at with the panel there. Basically had to "bend" the left side way down and fit my hand in to loosen it. After it was finally loosened, it was easy. Pull out the old ecu and pop the new one in and re-assemble.

I took it for a quick drive around the block and did not seem to notice any change. The only thing is the turning radius seem shorter now. Do you guys feel the change more at highway speeds?

itsallgood

I'm not sure if the L tuned steering ecu is supposed to shorten the turning raduis but I know its supposed to take the sluggishness away, it should feel more tight.

If you so a search on the steering ecu, you might find the answer your looking for...

Aloha

GS400_PUSHER

so you saying its not worth buying......

bitkahuna

iTrader: (20)

bad-gs... the cover around the key hole just pulls off - no screws/clips.

"quick drive around the block" probably isn't enough to notice the difference. What year/model do you have and what rims/tires?

I'm told the steering radius/ratio cannot be altered electronically, but the steering 'effort' tightens more quickly with speed with the L-Tuned ECU installed. So if you drive a bit more aggressively, I expect you'll notice the L-Tuned ECU more. It's not 'night and day' but it's definitely noticeable. Give it a bit more time.

Mr Johnson

It is defintely worth buying!

Bit: I wouldn't call the difference sublime either though. It should be pretty obvious from the moment you take the wheel.

bad-gs400

I think the previous owner had the L-Tuned already installed, since the ECU bolt looked like it had been removed/worked on. There is absolutely no difference in steering. I'm running 18's and I have driven the car about 200 miles with the L-Tuned ECU and also had a friend drive it, with the same conclusion. No extra tightness, less-slack feel or no-dead spot remedy. There really was never a dead spot to begin with, either. Since there is no difference, I might throw the original back in and end up selling the new L-Tuned. Any buyers??

shftup

Just had mine installed today, i feel the difference, it is tighter and more confident throughout. The tec indicated that they had to reset the main ecu, did u do this?
Anyways, can't wait to put on my l-tuned suspension, and 19" carlsson's.

bad-gs400

yeah, disconnected the negative battery terminal for 1 hour. no difference.....

shftup

It is possible that the unit is defective? I mean i have never read a post about the driver not feeling the difference. I did a search and only came up with this one. Maybe take it in to the dealership and they can validate if the ecu is all good?


not sure what else it could be.

bitkahuna

iTrader: (20)

If it was defective, he'd probably have really bad steering.

I think he said that he suspects he already had the L-Tuned ECU on the car which is why he didn't notice a difference.

bad-gs400

I don't think its defective, I just think the original might have already been L-Tuned. The units were identical. Does anyone know if there are distinctive markings which are different on the two units. I had to mark "oem" on the original I pulled out to make sure not to mix them up.

LexusL

I have the L-tuned ECU Chip installed on my gs and it feels much tighter like sporty cars. When you drive it on freeways then you should usually tell the different.

bitkahuna

iTrader: (20)

There are NO distinguishing marks between L-Tuned and OEM ECUs... this has been discussed a zillion times. I think the reason there's no diff is because Lexus is not going to sell a load of L-Tuned ECUs and to mold a different plastic housing just for the L-Tuned ECUs wouldn't be cost effective.

LexFather

True, the person that initally taught us how to do it said to scratch L-tuned in the L-tuned ECU so u can tell which is which.

I have stock setup with the L-tuned ECU and I could tell the difference right away.

RMMGS4

iTrader: (5)

Just got my ECU today. The PN on the bag it came in had a 5 digit prefix added to the PN I saw molded into the ECU plastic itself. The complete PN is 006444-89650-001. This is a logical way for Lexus to control their inventory, but once the unit is out of the bag, there may not be a way to tell the difference. If true, I'd still consider that bad practice on the part of the L-Tuned group and they'd deserve a good slap on the wrist for it.

It appears that the only difference between the stock and L-tuned ECU is the program downloaded to the ECU, but visually the parts are physically identical. The part number molded into the plastic is most likely used to identify the "physical" ECU part itself, not the software inside. That's acceptable, but the software version programmed into the unit should be marked somewhere that is visually apparent. Another PN, an "x", anything.

I haven't taken out the old ECU to figure this out myself, but I do see a couple of numbers/letters printed on the plastic in green and white ink. Could this be the way to identify the SW version?

The white ink stamp shows "23". The green ink is in three rows : row 1 is "11B" (only guessing, not legible), row 2 is "14", row 3 is "A54".

I'll check this myself this weekend, but if someone beats me to it, please verify what the "stock" ECU" has in the way of these markings.