airhead04

New to the forums. I own a 2001 IS300. Got it within the last week. I have a fully built 2jz going in, as well as a t56 magnum going in. I have a Haltech 2500 Elite going with it all as well.
Now my question is (yes I searched and can't really find for sure answer) do I need to keep the stock ecu intact? Or once the Haltech is in, I can toss it? I have been told by a couple of local guys who heard from their sister moms cousins that I need to leave it in to get it all to function. I am looking to keep all the amenities the car has stock, AC, cruise, horns etc. I mention those because I miss them on my supra haha.

Anywho, if you can either link me with a thread or know the answer for sure 100%, that would be awesome.

Cliffs: Haltech 2500, do I need to keep stock ecu to have everything function in car?

Thanks,

David

Hodgdon

This is a question for Haltech. You need to ask them if their 2500 ECU has the ability to run the CANBUS for your A/C controls, instrument cluster, and cruise control. I believe one of the current Haltech units has plug and play availability for the IS300, as well as the CANBUS support

Tuns0ffun

As far as I know you will still have to keep the main ecu due to the fact that all functions of the vehicle supposedly ran through the main ecu. That's why its technically easier to swap the 2002 and later vehicles. They split the ecus in 2002

daddystop

Your factory cruise control and traction control aren't going to work without using the factory throttle body/transmission/o2 sensors and factory ECU for it. Hopefully your Haltech can replace those functions but if not you might be looking at removing some of the niceties of your Lexus in order to make it fast.

Bempa

My findings when I did some research in this subject is that the only Aftermarket ECU that can "speak" the mystery Language of "MPX" as Toyota used in this era of cars is Link ECU made for Altezza, this ECU can be used on both 1JZ, 2JZ and 1UZ with additional wiring,

Here is a URL to that product
http://dealers.linkecu.com/TALTPlus , I was in touch with them and got it confirmed by them that this ECU can support the comfort functions that OEM Ecu normally runs.

Haltech ECU does not support "comfort" functions, so you either need to run it alongside OEM ECU, or you can get in touch with a guy on Facebook called Yury Baranov, he runs a facebook group where he is putting out information and selling his stuff. He has the parts knowledge to make a tranlsator from almost any ECU to Toyota MPX language. He should be able to make it work for you with Haltech ECU and his translator then you could ditch the OEM Ecu

Here is a URL to his Facebook group
https://www.facebook.com/groups/all4swap/

daddystop

^^ Now if ANYONE would make an ecu that could control the A650E I'd tell them to put themselves in for a raise and take the rest of the day off paid.

airhead04

Haltech elite 2500 can do all of the necessities. Without the stock ecu there.

daddystop

Not control an A650E transmission though. It's fine for a 5-speed/6-speed swapped car, but not if you intend to keep the stock (or built) auto trans. I did a TON of research on this before selecting the ecu I went with (and it still doesn't control the A650E transmission).

http://www.dicktatortransmissioncontroller.co.za/

This is the ONLY controller I've been able to find for this trans. I have no idea how well it works.

Hodgdon

Their page indicates this ECU is only for 1999-2001 models. Did they tell you different when you were in touch with them?

KrisOK

the G4 is the Link ecu made for IS300 01-05. It will only work on manual or manual-swapped cars, though. That ecu linked above is for a 3sge Altezza.

https://xcessivemanufacturing.com/ecuk-s8.html is the one for 1G IS’s.Seems pretty capable but only having one additional input kills it for me.

Does the ProEFI 128 not support the A650?


To answer the OP, I haven’t seen a true stock ecu replacement besides the Link. I have an infinity 6, and I’m sure it’s capable of replacing the stock ecu but no ones taken the time to translate between them. Much like your Haltech, quite capable of doing it, but no one’s actually done it.

daddystop

No aftermarket control over the a650e exists (that I know of) other than the Diktator Transmission Controller that I linked above.... and I don't even know how much I trust that. I've literally read 0 user experiences with the a650e + Diktator. There are two major issues w/ the A650E:

1. 3rd gear sprague is weak. This means that you cannot do any "high torque" upshifts from 2 to 3. You will break the sprague and be stuck w/ a transmission that needs a rebuild with new parts in it.
2. The solenoid control for this transmission is, as I understand it, controlled via PWM vs on/off solenoids that are used to control most other auto transmissions. This is why people that remove their stock ecu or do any kind of motor swap lose 2nd gear. The stock ecu, which hasn't been disassembled (code wise) because it's likely encrypted, controls the transmission's shift between 1 and 2 using a "special sauce" of PWM inputs to multiple solenoids. In my mind this is not easy to replicate even if you did know how it works because Lexus likely has multiple tables that determine any modification to the "basemap" of signals sent to the transmission. You can find plenty of stories online about people having a650e's that shift directly from 1st to 3rd when they try to hook it up to a manual controller like some race cars use.

I had to do a LOT of ****ery to keep my a650e in my car and turbo the stock motor. I have a thread talking all about it on here. Items that must work properly for the a650e to work properly are (may include more than what I know also):

1. Working stock throttle body with all electronics connected to it.
2. Stock ecu.
3. Stock o2 sensors or some way of simulating the "complicated" situation created by the stock configuration's 4 x o2 sensors situated in various positions within the exhaust.
4. Stock MAF.

The ProEFI 128 harness takes control of every other input/output on the engine harness outside of the above functions. The above functions all remain wired to the stock ecu. I'm fairly certain I have a unique setup that not many (maybe no one) has ever done "successfully". The "easy" way is to swap a 5-speed and a GTE into the chassis. Sure it's expensive but it gets around having to use 2 ecu's. I suppose there are other things that the stock ecu may still be needed for like door locks, hvac, stock gauge cluster, etc. I would LOVE it if anyone had a clue about how to make the stock ecu happy with the o2 sensor configuration once you get away from the split bank oem manifold. I have two upstream o2 sensors and 2 downstream from the cat..... the ecu is not happy with this because I think the signals coming from the 2 downstream cats need to not be identical. I do not know how to fix this issue.

Sorry for thread jack.

KrisOK

nah I’ve got gte + manual trans, still running stock ecu plus infinity. OP, you will lose traction control if you get a CEL, and most likely you will get one due to a too rich/lean condition. The stock traction control is modulated via the factory DBW and is activated by variances in Drive Wheel speed vs Driven Wheel speed that is sensed by the ABS sensors. Most modern standalones tie in to the ABS sensors and can activate traction control by cutting spark and fuel to the engine. You can put the dbw on the standalone and have it close the throttle during traction-loss events, too. This is how my infinity is wired. You will lose cruise control with this method. I never use cruise on a MT, so it wasn’t a tough decision for me.

Hodgdon

Thank you for the URL. The page says it is for the AUTO chassis only, though - and specifically NOT for factory Manual chassis cars (which is what I've got).

I'd really like to be able to do a FFIM with a larger throttle than OEM. I'd like to maintain my OEM instrument cluster and cruise control.

KrisOK

https://xcessivemanufacturing.com/to...uk-s8-890.html

that’s the url for factory manual cars. The gte throttle body works just fine on the GE ecu, so that is an option for an ffim. The gte does not have acis, so you’ll lose that unfortunately.