tennsmith

I am putting an LS1 out of a 2001 Camaro into a '36 Ford streetrod and have this question about implementation of the START function. In a modern day car w/automatic transmission, if the transmission is not in N or P and one turns the ignition key...NOTHING happens. I believe two separate functions are involved. #1, the neutral safety switch signal to the ECU likely prevents any ignition signal from reaching the engine unless in N or P, and #2, something interrupts the signal to the starter solenoid and the starter does not engage and crank the engine.

I understand how to wire and implement the neutral safety switch function, but if I connect the purple wire in the ECU harness from the starter solenoid to my ignition switch START terminal, it appears I can crank the engine, regardless of the signal from the neutral safety switch. It will not start unless in N or P, but it will crank. How does the factory wiring prevent the engine cranking function when not in N or P? This function must be external to the ECU and its wiring harness.

RockinWs6

There is a starter relay that is only activated in P&N AND the BCM.

jayyk31

iTrader: (2)

Just an fyi... The LSx pcm doesn't need to see a start signal. You can wire up your starter directly from the ignition switch through the pnp or neutral start switch (fused of course) and then to the starter. The pcm will know it is cranking through the ckp sensor. You don't need a relay if u don't want to use one.