The neutral safety switch wire that runs from the AT to the ECU is likely to be the culprit as this will tell your ECU not to start the car You need to check this wire from the ECU / connector through to the AT This is the wire that you should check for signal (voltage) and continuity (the smallest amount of resistance) at the pins and at the ECU It is one of the AT connector wires to the ECU JC
Use the FSM to check what is happening I suggest you use the FSM to check the signals and then back trace to find the cause. I suggest you start at page EF & EC - 63 for a start. If another correct ECU works then it is likely as was suggested that there is an open circuit in the ECU board or the connector attached to the board. Because the car cranks over it is likely that the signal to the ignition relay is not coming out of the ECU. I would start at wire number 9 on the ECCS (ECU to most people). Check to see if there is +12V coming out of this wire when someone cranks the engine over. If not then check this area inside the ECCS. Good luck. MichaelZ
I suggested he try FSM AT 56 - as AT code was thrown and car wont start FSM points to inhibitor switch or back from AT control unit (to ECCS pin)
