No Start? Battery cranks starter, fuel gauge goes to 1/2 when key is on?

I believe this vehicle had an interlock device in it at one time. Anything I could do here to bypass immobilizer. Connector(photo) plugs into female plug that ends(no wires)?

Installed a junkyard immobilizer amplifier from a 02 Avalon. Security light now stays off with key installed and also when cranking, but still no start. Previous 01 Avalon that I got parts from did not have an immobilizer or amplifier from the factory. Must have started that in 02 because the 01 was also an XLS like the 02 I have. Picked up another ECU and theft deterrent module when I returned the 01 Avalon parts and will install and attempt to start. Will post results shortly.

Still no start with new junkyard ECU and security light continues to flash when key is in ignition. So, the original ECU recognizes the key with the new amplifier and every attempt at starting it starts for a split second, then cranking only, but that is different from before. I'm noticing that tachometer is still not moving when cranking. Fuel gauge does go to correct reading. Am I on to something?

I also forgot to mention, original ECU with new amplifier, key in ignition does turn off security light, but key in either door turning key to unlock, does not turn off flashing security light. Would that indicate that ECU recognizes key in ignition, but BCM does not recognize key in door, meaning bad BCM?

Will have to check the tachometer tomorrow (Saturday) in the daylight. Am I looking for battery voltage at the black/orange wire?

The tachometer does move when the engine starts for a split second. Black /orange wire at ignition switch getting 12.5v with key on, 10.5v when cranking. Engine does not turn off when key is released, it turns off when key is in cranking position, but immediately starts each time the key is cycled, for a split second (with tachometer movement), then turns off.

I'm thinking maybe O'Reilly's CKP sensor could be bad (did read 3.3k ohms I believe) and drained battery ruined transponder key amplifier. Does that make any sense?

Tried the driver door window down with door locked again and reached in through open window and open door with inside latch and no alarm, even though key inserted in ignition lock cylinder causes security light to stop flashing. Seems that BCM is not recognizing key, but ECU is?

Correction: I thought I remembered CKP sensor reading (3.3k ohms) but I wrote in a previous message that it was (2k ohms) and I got a message back that that reading was correct, but I will double check both the original and new CKP sensor for resistance tomorrow. I read somewhere, maybe on this site, that O'Reilly's has made some bad electrical parts lately and also that aftermarket parts don't always work out on Toyota's. Is it possible for a CKP sensor to read correct resistance and still be a bad part?

Also, is it possible that ECU is now, with good transponder amplifier, able to recognize key, but be bad to the point of engine not running?

Both CKP sensors (2k ohms). With key on, CKP connector is reading(31mv/31mv). Reinstalled original CKP sensor and still no start. Tried different Theft deterrent module, and no change. Everything works on the door except key in lock in unlock mode does not disable security light on dash. Should CKP connector get voltage when key is in start position on voltage when in on position?

Is this statement true in your opinion for a 02 Avalon CKP sensor? The CKP sensor is the part that produces the voltage; it doesn't receive any from the ECU. Between the CKP sensor and the crank gear, they produce an on/off voltage when the engine is running, it is a low voltage around 2.5v, Base on the pulses of the voltage, the ECU determine how fast the engine is running.

Security does not flash now, when key is in ignition and also in start(cranking position) after I installed junkyard transponder amplifier.