My 2002 gmc envoy starts with remote but will not crank with keys

no info generic answer either fully remove aftermarket unit or notify company for assistance in troubleshooting unit

To arm content theft alarm.
1. Open the door.
2. Lock the door with the power door lock switch or
the remote keyless entry transmitter. The
SECURITY light should flash.
3. Close all doors. The SECURITY light should go off
after approximately 30 seconds. The alarm is not
armed until the SECURITY light goes off.

If a locked door is opened without the key or the remote keyless entry transmitter, the alarm will go off. The headlamps and parking lamps will flash for two minutes, and the horn will sound for 30 seconds, then will turn off to save the battery power.

Did you override the security system with security module if not you will have to do that it is a separate module that you will need

Could be the neutral safety switch if it won't crank in neutral or park, could also be the starter has failed.

either your connectors need cleaning or maybe a break in the wiring. Is there on spot where both wires come together if so check there.If there is any plugs, pull them apart and clean them with contact cleaner

U need to reset security system (pass lock II). Turn key to on right b4 cranking but don't start and let security light flash for about 10-12 mins until it stops and then turn key back off, repeat procedure two more times don't actually turn key far enough to start during first two 10-12 min cycles, third cycle though after flashing stops turn the rest of the way forward for it to start. This should then reset security and solve problem sometimes only takes two cycles to reset. Good luck, hope this is helpful & solves problem.

sounds like 1 of 2 problems. without the vehicle it is hard to say but first I would check the ignition switch and then look at the body control module. hope this helps,
The body control module controls keyless entry and most body functions including dash board operations.

Ignition switch and neutral safety switch. Next time it happens wiggle thekeys in the ignition switch and try to restart.If it starts its probably the ignition switch. Then locate neutral safety switch on brake pedal and put meter on B+ wire from switch to starter relay and see if you get B+ on the would -be- crank. Next locate B+ wire from starter relay to starter hook a meter to it and see if you get B+ on the would -be crank.
Where ever B+ is missing is your problem.

two things come to mind

1 fuel injectors are gummed up. get some berrymans chemtool and put it in the tank do it twice.

2 I had a ford ranger that had the same symptoms after warping two heads the mechanic discovered that the catayitic converter was blocked

If your 2002 gmc envoy or sierra will not even turn over with a kown good battery try starting it in nuetral then go back to park and try starting again. There is a park nuetral safety switch that can malfunction. Turn the key on then shift into nuetral, then turn fully to start.