Unusual no-start with key but remote start works
 

I have a new to me 1999 Blazer with a no start problem. The engine will run for a few seconds when started with a key then stall. The security light blinks once after it stalls then remains OFF. If I start it with the remote start, it starts and continues to run. If I insert the key after it is running, it will run normally and can be driven.

I tried the Passlock relearning process several times with no change.

Tim

If you have one of those keys with the resistors in it. Chances are itd bad. Try another key if you have one

I had a similar problem with my 98 4dr. Had to replace the ingnition switch and never connected the remote start again.

Probably a bad ignition cylinder. Previous owner probably had alot of keys on their key ring. This excessive weight will cause the ignition cylinder to wear out quickly. Pretty common issue on newer GM vehicles with the passlock 2 system.

Testing
 

Is there a way to test the ignition switch assembly? Mechanically, the tumbler and key show no significant wear and functions fine. I'm assuming the fault would be in the Passlock sensor.

Tim

The passlock system, if activated, will cause the engine to die shortly after it starts. It will NOT prevent the engine from turning over.

As far as the ignition switch goes, take a read through the Ignition Switch link in my signature below. The diagrams and explanations should be enough for you to get testing the contacts at the main connector under the steering column.

Solved
 

OK, the problem turned out to be a that the only key I had was a valet key instead of a passlock key. I ended up bypassing the passlock key with a resistor set to the same value as the remote start bypass.

All is good. Thanks for the help.

Tim

I have a 1999 as well also with remote start. Mine runs just has the security light going on and off staying on for durations. Another odd thing is I know when it goes on, not cause I see it but because the interiors lights flash on and off and the locks lock and unlock. Anyone have any ideas?