99 Suburban will not start with Security light on constantly.

I have a 99 Suburban k1500 that will start and stall out after a few seconds. The security light is on constantly and will not reset after trying all the procedures listed. I have even tried the resistor bypass trick using 3200 ohms as required in procedure. Light would go on and off intermitently for several months on regular pattern and would restart and run fine after setting for a few hours or overnight. Now it has been weeks after a tow home and nothing seems to reset it or work in bypassing it. I really would like to repair mysef as I do not have $700-$1000. to throw away to a dealer. Does anyone have any suggestions on what I may do to remedy this problem???:frown:

Normally a fault in the sec system will not allow the starter to activate. This may not be dyer job at this point, check fuel pressure at the rail you need 60psi minimum key on.

Vehicle has passlok 2 and starts rite up but cuts off after a few seconds just as they say passlok will do. Passloc will not reset as it has done in the past. I am sure it is not a fuel pressure problem as it reacts exactly as described for passloc failure. Vehicle has new style pump recently installed several months ago. Even when the passloc was resetable, I always had cranking starter availability.

Thank you for your input.

You need a high end scan tool that can access the Passlock module for DTC's. Most independent repair shops can do this for $35-$40. Once you get the codes post back with the numbers for more help.

This vevicle is not able to make a shop on it's own without a tow. Does any one know what the voltage should be on yellow wire from switch to passlock module? I have 12 volts to black/white wire and orange wire, but only .05 volts at yellow.I have been unable to get any one to come out to vehicle and test in this weather in the east. Thank You!

This vevicle is not able to make a shop on it's own without a tow. Does any one know what the voltage should be on yellow wire from switch to passlock module? I have 12 volts to black/white wire and orange wire, but only .05 volts at yellow.I have been unable to get any one to come out to vehicle and test in this weather in the east. Thank You!

With key in the "run" position the yellow wire should have 4.9-5.0 volts.

Thank you! I am going to replace EVO module and see what happens.

After replacing EVO security module with new #16264955 for $100.00 vehicle starts and operates like new again.

Thank you to everyone for your help and input!

After replacing EVO security module with new #16264955 for $100.00 vehicle starts and operates like new again.

Thank you to everyone for your help and input!

most at this age have a automotive lock smith do the dis-able of the security system. good luck with the repair ..
If this occurs soon ,just have it removed.....dealership to repair this is about 1000 USD.. locksmith is much cheaper...they have much experience with these vehicles.

I had the same issue that drove me nuts. I finally accidentally lost the remote key fob that we always used (it broke off the ring). I put a battery in the other one we got with the vehicle and it never happened again. There was something wrong with that remote that would activate the security system. Don't use your remote for a while and see if that works.