Confirm year of vehicle is a 1997, since that’s what you mentioned in your first post. A “signature “ always helps.

Flashing SECURITY light (once per second) indicates there is an open or a short in the wiring between the lock cylinder and the BCM (96/97 only). It can’t read the key resistance. If the resistance was wrong, light would be on constant.

The fuel pump will always prime for two seconds and shut of. It will not be restarted until the PCM receives the fuel permit signal from the BCM.

Shoebox's writeup covers all this in more detail.

4th Gen LT1 F-Body Tech-PassKey/VATS

 

Correct
1997. I’ve built the 383 stroker. Is this a malfunction with the key?
Will bypassing the TDR correct it? I did read his write up on this.
I’d just assume do away with the system. Is it as simple as bypassing the TDR and wiring in a resistor for the vats wire?

 

Yes, bypassing VATS is as simple as placing a resistor with the same resistance as your key into the connector under the steering column. Make sure to put the resistor on the BCM side of the connector, not the steering column side.

 

As Shoebox indicates, a flashing SECURITY light can be due to 1) an open or shorted circuit from the key cylinder to the BCM, OR... 2) a defective key (not because of incorrect resistance). And it could also be 3) a fault on the printed circuit board in the BCM.

Bypassing the TDR will allow the starter to crank. But you still need the 50Hz square wave “fuel enable” signal from the BCM that goes to the PCM and tells it to turn on the fuel pump. You can buy a bypass module (not the same as the key resistor bypass) that supplies that signal, and wire it into switched power and the PCM. Shoebox covers this in the writeup.

If you rewire the TDR to bypass it, and wire in the fuel enable bypass module, you don’t need to do anything with a resistor.

 

Thank you for the great info. It turns out that the vats was deleted when pcm was reprogrammed. I still had to ground theTDR to crank the engine. It did crank and I’ve turned several times without the plugs to oil the engine.I’m almost ready to start the engine. I’ve ordered a bypass module if I do end up needing it. Not sure why if it was deleted that I needed to pass the TDR.
Hopefully I’ll be writing back soon with good news on the build.
Thank you.

 

If PASS-Key (VATS) was deleted from the PCM, the PCM doesn’t need the fuel enable signal to activate the fuel system. Did I miss that delete info in your earlier posts? I didn’t read through them again.

Bypassing PASS-Key in the PCM does not eliminate the need for the key to be read, and the BCM to send starter enable power to the TDR.

 

No. I was unaware that it was deleted. I’m on the right track now. Thank you. It’s looking good.

 

Well I’m up and running. Unbelievable this task. Not running good though. Will idle until it warms up then it’s hit and miss. Runs fairly strong at 3/4 throttle. If you hold throttle steady for a bit then let it down slow it will idle sometimes. I found 1 vacuum leak and allows it to run half ***. The motor oil pressure every thing is sound seems like best I can tell but it’s running terrible other than nearly wide open. Off coarse I’m not going wide open trying to break it in. It’s almost like there is another vacuum leak but I’ve sprayed the engine and doesn’t seem like so
i pulled 1 cylinder plug and it was black maybe normal
my check engine was on until today it when off out of the blu then came back on. Temperature is doing really well.
security light still flashing
bypassed The TDR.
anyhelp would be greatly appreciated
I believe the build is going to be sweet once I get it straightened out
pcm for less did the tune

 

It’s not drivable if that helps with symptoms

 

Are you running it with an OBD2 1997 PCM? Who tuned it for the new displacement, cam, injectors, etc.? You really need to add a signature.

https://www.camaroz28.com/forums/lt1...nature-879835/


Scan it for codes.... the SES light is trying to tell you something.

Have you verified the Opti is indexed correctly to the cam dowel pin? Are you sure the timing set is indexed correctly? Have you verified the plug wires are connected correctly? ..... the injector wires? Are the O2 sensors hooked up correctly? Is the exhaust system complete - no openings, no leaks, etc.?

 

PCM for less. 1997 pcm

all tuned for my build injectors etc. The timing is set properly and opti is correct. All plug wires good.
No exhuast leaks. Everything is plugged up and should be good. I’m convinced that it’s related to the 02 sensors based on how it runs until warmed up.
the little coolant light with the arrow is on but cooling system is operating very well.
not sure why the light
maybe the ses light is due to the improper key from loosing the original

I remembered using sataline torch to remove the 02 sensors from factory manifolds. Maybe I damaged them ?
I’m betting the car will run good Tommorow on an open loop with the 02 disconnected.
maybe this will give me a direction to go.
it’s definitely in the fuel air.

 

I didn’t see an easy way to make a signature but I’m definitely going to add on. I know I’m a step or two away from this thing running properly without throwing money at it. Appreciate you

 

Exhaust is pacesetter long tube with dynomax welded to passenger side header and 18 inches of pipe and muffler on driver side. I intend to get duals out the back eventually

 

The cooling symbol with the arrow is for the low coolant level switch on the radiator.

The PCM has no way to know about past key problems. If it gets the fuel enable signal from the BCM it turns the fuel pump on.

Get a code reader.

Black plug means it’s running too rich.

 

Your key or the low coolant light would not set the SES, as Fred stated you need a reader rather than guessing. I wouldn’t think the torch on the O2 sensors was good either.

Blue Driver is $100 and connects to your smart phone. I have one and been pretty happy with it.