mikellucci

iTrader: (56)

Hoping someone can help shed some light around the communication the stock ecu, immobilizer and key fob share when it comes to programming and starting the car. I need to find a way to start my ISF motor using the ISF ECM, my is350 immobilizer and my is350 key.

As I understand it the 2nd gen lexus IS's KEY security system is certificate based with a sequence of exchanges happening between the engine ECM and immobilizer before the engine is allowed to start.

If I am introducing a foreign engine ECM to my preexisting immobilizer and transponder key what steps would need to be performed to sync everything up? Would I need to:

1. Register the engine ECM (assuming it's by VIN) with my existing immobilizer
2. Sync my key fccid with engine ECM

Sounds simple but I have concerns with the ecu and immobilizer portion assuming this can only be accomplished with real Techstream and not the black market version everyone now owns to turn off their drls or register tpms ids.

I came across an old thread for smart card key and it looks like these are the screens needed to perform the changes?

Can anyone tell me if these screens/access exist using their Techstream:

Select Smart Access
Selecting new key registration
Utilities then Smart code registration






Thank you

kamileon

If you installed the 09 isf ecu, why does it show is350

kamileon

If your not replacing the steering columb, the id box, certification ecu or keys, the isf ecm should work fine. the car will start and shut off the first time started but then should run. If the transmision park/nautral switch is unplugged then it wont start. check in the data list if you see the car in park.

mikellucci

iTrader: (56)

That's not my car, its a screenshot of someone that posted those screens in 2010.
Again, I have the ISF ecu, is350 immobilizer linked to is350 key. Everything is from my IS350 with the exception of the new ISF engine ECU.

I cant exactly start my car ATM and see what Techstream displays

Meguerra

iTrader: (8)

They are not from his car, Screen shots from an older thread.

codenko

iTrader: (8)

The screens show up on my techstream when I have it plugged into my 08 IS250. I haven't gone any farther than that because I'm too afraid of unregistering my own keys and not being able to start my car.

mikellucci

iTrader: (56)

Great news, thanks for sharing that.
Gives me hope I can accomplish what I need to when the time comes in a few months. Thanks

mikellucci

iTrader: (56)

Confirmed that the VIN is infact seeded in the engine ECM.

The engine ECM, immobilizer and smart key will send a signals to/from one another and need to receive the correct certificates in order for the car to turn over.

Soooo, I need to have my ISF ECM reseeded with my IS350 VIN and it looks like this can only be done with a Techstream on a DEALER IP ONLY.

mikellucci

iTrader: (56)

In case someone ever does a motor swap or has to buy a new Engine ECM for their car....this will save you a huge headache!

Its PROCEDURE G found on TIS !!!!!

Most dealers do not know this exists or are ignorant to the fact that it can be performed!

(g) PROCEDURE "G"
ECU communication ID registration

NOTICE:
· The ECU communication ID should be registered when the ID code box (immobiliser code ECU) and/or the ECM is replaced in order to match these ECU communication IDs.
· The engine cannot be started unless the ECU communication IDs match.
· After the registration, pressing the engine switch may not start the engine on the first try. If so, press the engine switch again.
· Clear DTC B2799 (code for ECM immobiliser communication error) by either of the following:

- Use the Techstream.

- Disconnect the battery for 30 seconds.

(1) Using SST, connect terminals TC and CG of the DLC3.
SST: 09843-18040

(2) Turn the engine switch on (IG) and leave it as is for 30 minutes.
HINT:
Do not start the engine.

(3) Turn the engine switch off and disconnect terminals TC and CG.

(4) Check that the engine starts and stays running for more than 3 seconds.

8. VEHICLE IDENTIFICATION NUMBER (VIN) REGISTRATION
(a) DESCRIPTION
HINT:
This registration section consists of two parts: Read VIN and Write VIN.
(1) Read VIN: This process allows the VIN stored in the ECM to be read in order to confirm that the two VINs, the one provided with the vehicle and stored in the vehicle ECM, are the same.
(2) Write VIN: This process allows the VIN to be input into the ECM. If the ECM is changed, or the ECM VIN and vehicle VIN do not match, the VIN can be registered, or overwritten in the ECM by following this procedure.
(b) READ VIN
(1) Confirm the vehicle VIN.
(2) Connect the Techstream to the DLC3.
(3) Turn the engine switch on (IG).
(4) Turn the Techstream ON.
(5) Enter the following menus: Powertrain / Engine / Utility / VIN / VIN Read.
(c) WRITE VIN
(1) Confirm the vehicle VIN.
(2) Connect the Techstream to the DLC3.
(3) Turn the engine switch on (IG).
(4) Turn the Techstream ON.
(5) Enter the following menus: Powertrain / Engine / Utility / VIN / VIN Write.