If the antitheft light is blinking on a 2000 Chevy Malibu and the car will not start how do you fix this problem?

Answer 1

My name is Monique. I have had the same problem with my 2005 Chevy Malibu LS and the Anti Theft light coming on and then having to deal with being stranded. This has been happening to me for the past year. I recently had my CMB (control body module) changed and I haven't had anymore problems with the Anti Theft system. But when you change the CBM it will lock your radio and you then have to go to the dealer to have the radio code reprogrammed. I haven't took mine so I don't know how much it will cost. The following was posted by a fellow named Goody on a different forum, god bless him caused he saved me a ton of money on this issue, and it seems he and another fellow definitely did their research, and have at least pinpointed the source of this issue:

Ok, I'm going to expound on the graphite issue.

Background I have a 2001 Malibu with 92K on it. About a month ago it started having no start problems. I replaced the plugs, and started looking. After internet research I was pointed to the Anti-Theft system. Since I am an electronics technician and as such wanted to figure out how it worked, so I contacted an excellent auto electrical mechanic and here is what we found.

ALL GENERAL MOTORS PRODUCTS FROM 1997-2005 CONTAIN AN ANTI-THEFT SYSTEM CALLED PASSLOCK. Now for more, it seems the PASSLOCK or PASSKEY system comes in two flavors one is an option, version 2 and version 3 (optional on some models). PASSLOCK works by sending a voltage code to the BCM (Body Control Module)that enables the fuel pump or fuel injectors, so if kicked in the vehicle looks like it has no gas, and the THEFT light comes on or flashes if the incorrect key is used. If the theft light is flashing the system has lost the key code, on solid is a tamper.

Version 3 can be identified by the key, it will have either a 3 or + symbol on the blade of the key. This key contains a resistor that is connected when the key is placed in the lock assembly that enables the vehicle to start. There are numerous resistor key combinations available, and have to be matched to the lock and vehicle. Tiny wires in the lock itself connect to the key and these tend to break and are not repairable, the lock housing must be replaced. They can be bypassed by reading the resistance of the key and putting an equal resistor across the passlock wiring.

Version 2: my version, standard on GM vehicles. Consists of a lock cylinder and lock housing. The lock housing contains a pair of hall-effect sensors, the lock cylinder contains a magnet(s). When the magnet passes within a certain distance from the hall-effect sensor the sensor is switched on providing the voltage to the BCM. Since there are two sensors both must be enabled, if only one makes up then the vehicle is TAMPERED and will not start. If the magnet becomes gummed up or sticky and does not move to the required gap the vehicle is tampered and will not start but will crank. If you search on Google for passlock there are several sites that show how to defeat this scheme. Most all involve taking the dash apart to cut the yellow wire (data to BCM) while the vehicle is running, this will give a constant ANTI-THEFT lamp on the dash, and a fail signal to the BCM, this will work if you never disconnect the battery or have it go dead.

My solution is lubricate the lock, several posts I read said use contact cleaner, that will work but the residue (wax lubricant) left behind will eventually gum up the works again.

Here is my suggestion, go the hardware store and purchase a small tube of powered graphite lubricant, and a can of dust-off or similar computer cleaner. Put a tiny (tip of fingernail) puff of graphite in the key slot and use the dust-off to distribute it, set the parking brake, insert the key, put the shifter in reverse and make numerous start cycles of the key, going to park and removing the key each cycle (saves wear and tear on the starter). Put in another puff of graphite and hit it with the dust-off again and repeat cycling. That should cure the problem, if it acts up again lubricate it.

As a practice lubricate all of the tumblers in the vehicle and the house since you have the necessary tools once a year. If you desire further information please email me at goodys'at'charter'dot'net, I will answer them if I can, or point you in the right direction.