Security Light and Starting Problems on GM Cars

Security Light and Starting Problems

GM Security Light Symbol

A lot of people have written about the security light and starting problems on GM cars. The most popular models affected are the Chevrolet Malibu and Impala from 1997 through 2006.

However, the no start due to a security malfunction issue is just as common on other General Motors cars that use the same key identification system. These models include the popular Pontiac Grand Am, Oldsmobile Cutlass and the Alero from 1997 through 2006.

Here we’ll identify the root cause of the problem and discuss how to deal with it. We’ll supply information on how to bypass the system or reset it so you can drive the car to its destination without making any major repairs.

We’ll also learn about setting up a toggle switch to bypass the security on command. But most importantly, we’ll talk about how to fix this problem the right way. This is done by replacing the factory installed lock cylinder and key.

No Start with the Security Light On

GM ignition lock cylinder kit

Like most General Motors issues they had good intentions, but they were poorly implemented. The idea behind the system is to reduce theft by matching the key held by the driver to the automobile.

The transponder chip inside the key must match the code contained in the memory module of the lock cylinder for the engine to start. If you look closely at this picture of the lock cylinder you’ll see a little black plastic box attached to the topside of the lock cylinder.

It has a connector and wiring that run to a control module. When the lock cylinder identifies the proper key it sends current to the control module. This allows the vehicle to start and stay running. If the identification module doesn’t see a match it will illuminate the security light and prevent the car from starting.

Depending on the year, make and model the light might flash or it might stay on solid. In either situation this car will not take you where you want to go. Sometimes it will start and run for a second.

And sometimes it won’t start at all, it will just crank. In a normal situation the light should be off. This is how you tell the difference between a security light problem causing a no start condition and just a car that won’t start.

If the engine does not turn over, you can take a look at this information on diagnosing starters and alternators for additional tips.

Fixing the Car Won’t Start Security Problem

The problem boils down to a malfunction in the code reading portion of the ignition lock cylinder. This part isn’t serviced separately so you have to replace the entire ignition assembly.

On the Chevrolet Malibu and Impala, where the key is inserted into the dash to the left of the stereo, it’s not really a difficult repair. Two bolts hold the cylinder assembly in place and it has plug-in connectors on the back.

Replacement lock cylinders are available from your dealer, but with the size and scope of the problem aftermarket companies have jumped on board to provide solutions.

On the left you will see an ignition lock cylinder offered on Amazon for less than $60. I like this unit because it comes with complete instructions. Most importantly the instructions include how to program the new key and lock cylinder. I hear the dealership is charging $500 or more for parts and labor.The drawback to using this method is now the automobile will have two separate keys. You use one for the ignition and then you’ll have the door and trunk key. On automobiles that use a key fob remote to open the doors this isn’t really a big deal since the actual door key is never used.

However, some will not like the idea of having two keys for one vehicle. The dealership has the capability of coding the replacement lock cylinder to match the original key. Mobile locksmiths can also offer this service.

Bypassing the Security Light Issue

Sometimes you find yourself in a situation where you don’t want a permanent solution you just want to get the car to its next destination. Unfortunately, the most reliable method could take 10 to 20 minutes. Regardless, I will explain that procedure here and now.

Since the malfunctions root cause is the lock cylinder doesn’t identify the correct key, you can reprogram it right there on the spot. This means turning on the ignition to the accessory position.

Then you leave it that way for 10 to 20 minutes until the security light goes out. In tribute to the ingenuity of the general public, I see a couple of videos of how to set up a toggle switch to bypass the security lockout when the key is not identified.

There’s two yellow wires that go into the connector that attaches to the identifying module on the lock cylinder. You can mount a toggle switch across these two wires and mount it in an inconspicuous location.

When the light stays on or begins flashing you can correct the issue by operating the toggle switch. Now you don’t have to worry about having two separate keys. The downside of this is if someone finds the switch they will have an easier time of stealing the automobile.

My Relationship with the Malibu and Impala

My family has three Malibu’s and one Impala in the fleet. They bought these vehicles, because at the time I worked at a General Motors dealership. Now the cars are between 10 and 20 years old.

Unfortunately, these cars have become somewhat troublesome. Despite me retiring to Florida, each family member feels it necessary to notify me of individual problems with these cars as they occur. Lets just say my phone rings a lot.The oldest, a 1997 Malibu, now has 185,000 miles on it. The car is also 20 years old. Nevertheless, my nephew expects it to provide trouble-free operation on every key cycle. The reality is that nothing lasts forever, not even a Chevrolet product.Return to the auto repair news section and review more common car problems. Bookmark or share this page with someone having this problem.