So to make a long story short I bought my car not running. It's a long story but the main part is that it was believed the original ecu might've been toasted by an HKS FCon. The guy putting the car back together thought the ecu got fried so he tried a different ecu. Here's where it gets flakey. He said he flashed his Ron on another ecu and used the immobilized off the 1st ecu. I didn't think that was possible. Anyways nothing changed but what I wanted to know from you guys is if the immobilized code was not right will the car turn over but fuel pump not get power or will it start but die shortly after. That's my main problem is my fuel pump gets no power. I borrowed another relay for fuel pump relay 3 (in the engine bay) and I'm going to quadrupple check fuses in the engine bay bad under the dash).

Can anyone clue mr in if that's possible (same immobiliizer code on 2 different ecu's. And if an ecu doesn't have the right code will it just cut power to the fuel pump

 

The car might "turn over"... but basically as soon as you release the key it will die.

The immobilizer is matched to a chip inside the key. You can change to whatever ECU you want as long as the immobilizer code (as set in the ECU) matches the code built in to the key.

Alternatively, you can disable the immobilizer to check if that is your problem.

I'm not sure the exact method the ECU uses when the immobilizer engages. I would assume it was just cutting fuel or spark.

FYI there are 3 relays for the fuel pump and a resistor, all of which could conceivably go bad. You could power it directly to test and make sure this is your problem.

 

I tried repalcing the 3rd relay which is on the firewall last night but that didn't work. I'm going to run a hot wire to it form the battery tonight and see if the fuel pump primes...if its does then I know the fuel pump is good (It should be its a brand new Walbro). If the fuel pump checks out fine then I will have to trace the circuit out and see what is not allowing power to get to the pump socket.

So I can have any ECU from the same year EVO in the car as long as it matches the original immobilizer code from the first ECu because its immobilizer/key specific not ECU specific...is that correct?

 

It will turn over but it will not start. I tried it.

 

So if my original ECU is fried....what are my choices......I dont want to disable the immobilizer if I don't have to. So regardless if you put the imob code into the new ECU on the same car (The immob from the original ECU) it will not work? I can';t seem to get a straight answer (or maybe I'm too stupid to understand).

 

you can re-enable it after disabling it for testing purposes, and its not really going to stop someone from stealing the car anyway

 

Thats true. Its bit 3 in the periphery right?