security light, infl. rest light

[gr8tylor]

I have a 92 Buick LeSabre I recently got to fix up and the security light is always on, It dosen't effect anything that I can tell but it's annoying. I also replaced the airbag because it was in a previous accident and the infl. rest light is still on, do you knoww how to turn it off? It flashes when I first start up the car now.

[avatar307]

The Security light being on all the time is an idication that the Pass Key module has going into Bypass/Fault Detect mode. That means either the contacts in the ignition keyway are worn out, or the resistor plug on the key is worn out. When the Pass Key module cannot read the resistance of the key at all, it lights the Security light to indicate a Fault. When no reading can been determined from the key, the module assumes that the correct key has been inserted, goes into Fault/Over-ride/Bypass mode, and allows the car to start.

Try the other key to the car, that may fix the problem. If not, you most likely need to have the ignition cylindar pulled out, and the keyway contacts replaced. If that doesn't correct the problem, then most likely the Pass Key module itself is bad.

The Air Bag/SIR/SRS light illuminates because it detects a fault in the air bag system, because the control modules internal memory is full, or because a fault code has been stored that must be cleared manually (the code will not automatically assume a history code status). Most likely your case is the latter, and it is most likely the code for Frontal Impact Detected. I'm pretty sure that is one of the only codes that will cause the SRS light to stay illuminated until cleared with the appropriate scan tool.

This is because it's not a component fault, such as a low loop resistance or air bag disconnected. The module can detect when those problems have corrected, will shut the light off, and store the code as a history code. However, the Frontal Impact Detected code is.... informational, so it will not turn off the light until a diagnostic tool recieves the code and it is acknowledged.

Alternately, if the car has been involved in multiple accidents severe enough to cause the air bags to deploy, then the control module memory may be full. The control mondule acts like a black box and stores a large amount of details about what happened immediately before the accident, this memory cannot be erased.

Beyond that, when your accident occured, if ANY of the sensors were damaged, they also must be replaced in addition to your air bags. The air bags, arming sensor, coil, and descriminating sensors all function in various circuit loops. If any one component fails or is damaged at all, the module will turn on the air bag light.

The control module determines faults in the system depending on known resistances, the system is so sensitive it actually takes into account the resistance of every connector in addition to the sensors. Thereby, even if the sensor does not appear damaged, the components inside may be damaged enough to cause a abnormal resistance to be added to the diagnostic energy reserve loop.

Repair or all air bag system sensors and components is by replacement only. None of the components can be serviced in anyway, largely due to the tight resistance requirements. In addition, use of a multimeter on any portion of the air bag system can cause the deployment of the air bags.

Air bags contain explosives.

Don't mess with anything connected to them unless you know exactly what you're doing. That's why all the connectors are bright yellow and require 3 steps to disconnect them. The simple act of disconnecting one component, in addition to another component being faulty, could feasibly cause air bag deployment if the connectors are not disconnected in the proper order.