Bypass security

FRANKSANDLIN

MEMBER
2004 PONTIAC GRAND PRIX
3.8L
6 CYL
2WD
AUTOMATIC
240,000 MILES

Which security system does the car listed above GTP Comp G model have? I lost keys, drilled ignition cylinder and started car with screw driver it ran fine except DIC. Then shortly after, started having cranking and running problems. Started checking wiring and found a remote start (I think is aftermarket) which I removed. Finding cut and spliced wires everywhere. I have repaired wiring and replaced lock cylinder with one that does not have a module on lock cylinder or transponder wire and it still cranks sometimes and run fine some times. What does it take to completely remove this system. It's a cheap car that has high miles and I can't see purchasing all of the factory(expensive) parts that may make it run and how long they will last before other security parts go out. This car is fifteen years old, so someone must have hacked it by now.

1 Reply

STEVE W.

MECHANIC
13,465 POSTS

That car uses the pass-lock system, there is a sensor on the lock cylinder housing that reads a magnet on the ignition cylinder. From your description it sounds like whoever installed the remote start may have also installed a bypass box as well. That is the only way the car would start without the correct parts. Something is sending a valid key signal once in a while to make it run at all. The easiest way to repair it would be to find that box and remove it, then replace the ignition switch housing and lock with one from a salvage yard. That would restore the correct operation and not have anything that will shut it down at random on it's own. There really isn't a hack that works all the time as you have found out already. As for the rest of the system. The only common failure on these is the pass-lock sensor on the ignition housing itself. Even then they go a long time.