Ok, just to be clear and make sure before moving forward since others have worked on your car.

1) Very important, did you ever personally witness this car running properly for yourself after the Engine ECU swap, and if so how long?
2) Is the Red Security light blinking at a steady slow rate with equally on and off pulses with no key in ignition(if not describe the sequence)?
2) Does the Red Security light stop blinking when sliding in the key?
3) Does the Red Security light stay off when the key is turned on all the way or cranking engine?

BTW, Engine ECU swap is considered DIY by many people and is easy.

Step by step walkthru here: https://www.clublexus.com/forums/rx-...preciated.html

 

Sorry I guess I wasn't clear on what I said about the ecu. The Lexus was running with the original ecu after the wire was pulled it didn't start anymore when I tried to put a scann tool there was no communication at the DTC port that's why I changed it . Now the immobilizer when I put the key in it stops blinking and when I remove the key it blinks again a slow uniform pace . It also stays off when I try to crank . I'm getting no spark . No fuel. The check engine light stays on as I crank it the rpm gauge doesn't more .

 

Thank you for new info.

Ok, so here is where we are at best I understand you.

1) Red Security light is blinking slow and steady pace with no keys in ignition: Good, this confirms it's not a security system issue or power source branch open from "Short Pin" forward.
2) Your key test: Good, this confirms it is NOT an immobilizer issue with swapped Engine ECU.
3) Your Crank Sensor ohm test: Maybe good?, you ohm'd thru the Crank sensor from the Engne ECM plug with battery disconnected and are reading 2.1 ohms. Hopefully someone has the ohm specs on the sensor,... if not I will dig in the manual or do a test on my car to compare.

Now that you fixed the last guys mistakes on the Crank Sensor wiring, haha. - I am now questioning whether the Swapped Engine Ecu was not the correct part # or maybe it is a failed unit and you added extra drama and chased your tail in circles by swapping it. You already proved in your info posted above that your Immobilizer is "shaking hands" properly with the Swapped Engine ECU with your key test. This means it is not a "brain dead" Engine ECU but if we understand you correctly the Engine ECM was swapped after the wires were pulled. Ok, so not brain dead but will it run the engine properly is the question.

I would put your original Engine ECU back in and try again if it was my car since that was your last "Known Good" running configuration.

Hint: Every time after swapping the Engine ECU the "30 minute pairing procedure" will need to be done again to satisfy immobilizer. This needs to be done every time even if swapping back to your original because the Immobilizer and Engine ECU make a "unique pairing handshake". A little bit of a pain but it's nice to have a spare Engine ECU for days like this when we are questioning whether we have a bad ECU or wiring or other. lol

Link above for step by step walk thru.

 

I did put the original ecu in but nothing and the ecu I have now is the same part number u think it's a bad ecu. I forgot to mention when I put the new ecu the s security system always acted the same like it was a plug n play what I mean by is the security blinking light always blink the same if I put a new ecu without the immobilizer and ecu meeting the security light still blinks the same . I hope you understood what I said lol.

 

Lots of info so hang on for full explanation.

Every time the Engine Ecu is swapped it overwrites the "unique handshake pairing data" in the Immobilizer Ecu EEPROM.

Another words, the second you swap back and forth between the Engine Ecu's- the Immobilizer Ecu is killing your ability to start the car(no fuel & spark) unless you go thru the "30 minute pairing procedure" all over again. This is becuase your Engine Ecu "handshake data" is deleted from the Immobilizer Ecu EEPROM memory every time, like it never happened. lol

To see why, here is more info and proof than you will ever need. lol
link: https://www.clublexus.com/forums/rx-...a-signals.html
Link: https://www.clublexus.com/forums/rx-...xperiment.html

ADDED-
Hint: If it was my car I would put in the last "known good" Engine Ecu I personally witnessed running the engine- And "pair it". Now you can check your work after fixing the last guy's mistakes.

One more thing- A VIN# must be programmed into the Engine Ecu for the "30 minute pairing procedure" to work.

It doesn't matter if it's your actual VIN or the last guy's VIN or your next door neighbors VIN, just need a compatible VIN and not left BLANK- or will fail. VIN#'s are left intact and not changed during swaps so don't worry, it wasn't deleted.

 

Dammit it, I just thought of something and wish to add as a 2nd post to avoid confusion.

The reason your Immobilizer may appear satisfied is because your existing keys are registered & valid in the Immobilizer EEPROM. Therefore you are getting correct Red Security Light indications when doing the key test- HOWEVER still Immobilized- no fuel or spark!

Reason: Because you did not "pair" the Immobilizer Ecu to Engine Ecu when swapping back and forth- you are being "Immobilized" during the "handshake" between the Engine Ecu and Immobilizer Ecu when attempting to start the car. Even with happy keys.

Two things need to happen to get fuel and spark.
Step #1: Happy keys: Good, you already proved it likes the keys and Red Security Light is responding properly.
Step #2: Handshake between Engine Ecu and Immobilizer Ecu: Fail, you have no fuel and spark. This is not decided until you turn the key on or crank the engine. Takes 1-2 seconds to cut fuel and spark.

Simple answer: swapping Engine Ecu always requires "30 minute pairing procedure" everytime- see post above and links if you are need more convincing.

On a side note- you have no evidence the tech swapped the Engine Ecu properly. If the swapped Engine Ecu had a wiped or blank VIN during the "pairing procedure" it does nothing to add the VIN after the fact- guaranteed fail. Unless you can verify their work we have to assume a failed "pairing" if you have no fuel and can prove it.

 

Just giving a update on my situation . You know how I asked if it matters what wire goes to what terminal and I believe they said it doesn't matter . Well Lexus friends it does matter all this time it's was the wire being in the wrong terminal I should of listened to my gut feeling. But anyways I got it running now thanks to you guys at Lexus club. I thank you so much .

 

Good job and thank you for posting your fix!
This is why I don't let anyone touch my car.

You trusted multiple people to work on your car and replaced the Engine Ecu too while trying to reverse engineer other people's mistakes. haha

Yes, it does matter which way the Crank Sensor wires are connected and it would be quickly seen on a scope as an inverted sine wave crossing the cam sensor signals going the wrong direction, very obvious.
I figured you already tried both ways of hooking it up because that's what most would try when all hope is lost but I should have confirmed. I'm gad that's all it was because changing the Engine Ecu just added more drama and unknowns.

Another member slipped a timing belt and his Engine Ecu must have considered it a catastrophic fault with the Crank sensor and Cam Sensors so far out of spec because he also reported no fuel and spark, couldn't connect with scanner- very similar to a failed Engine Ecu or being Immobilized. He replaced his fuel pump trying to figure out what was going on.