We're putting together a daily driver 1991 Camaro RS 305 TBI. I have a used replacement 8746 ECM (car did not have the original ECM when purchased).

Currently, car will crank (starter was probably overridden due to old remote starter - now removed) but giving 53 Security code (+ security light on, no fuel from injectors). Tried the resistor pack as the wires inside the column aren't reading the pellet. Still getting the code. (This was all with a mechanic-friend's help).

BTW, It has a new fuel pump, relay, filter, and lines.

We're thinking that the VATS module isn't sending the signal or the ECM is looking for something else. Just received my VATS bypass module today, but it shows 2 different pin-outs for the TBI. I found a schematic bor the 89-92 ECM but pin B6 on the diagram is "not used".

How do I know which pin is the correct one to connect the signal to (and I don't need to know *why* I should just fix the VATS or whatever, the car's not really THAT nice to worry about fixing it).

 

I guessed (based on the schematic I had) and it worked! Started with a little help from the magic starter fluid. Now it starts on demand.

(It was the Blue wire coming from B6).

One question, if anyone else has used the little green bypass (4-wire), is the security light supposed to stay on now?

 

Most likely will stay on. It is driven from the VATs box, which isn't getting the proper resistor value.

Can just take the bulb out of the cluster.

RBob.

 

I am glad you had good luck with that bypass. I could never get mine to work. Bought a different kind and it still didn't want to work.

All the threads I have found here and elsewhere have said that the security light will be on all the time.