Today’s Symptoms:

An ATS customer complained about a 1997 Bonneville Security light coming on the dash panel and of course the engine won’t start. The engine started briefly when a direct battery power was connected to the starter wire and cable. Hooking up a fuel gage, the fuel shuts off after cranking the engine with a remote starter.

Diagnostics on 1997 Bonneville Security Light Problem:

When the security light comes on, it means the anti-theft module is activated and tells the engine control module (ecm) to shut the fuel. Also, this same module controls the starter enable relay to shut the starter so the engine cannot be cranked by the ignition key.

Troubleshooting the security system needs a wiring diagram if the security light is on. The starter solenoid purple wire can be tested for presence of 12v and if none shows up, check the starter enable relay pin A2 and C1 terminals for 12v coming from ignition switch. If there is no 12v, check the ground supply from A1 terminal at starter relay and A4 terminal at pass key decoder module.

Tips:

You can supply your own ground direct from battery negative using a jumper wire. If the engine starts and fire up then the decoder module is likely defective.

The ignition key has also a pellet resistor implanted inside. ATS specs can show you the specific resistance to bypass the decoder terminal pins B7 and B8 which depends on the resistor specs given by the vehicle manufacturer or call your dealer with the vehicle’s VIN number.

You can also check the integrity of decoder B7 and B8 circuit by measuring their resistance while the ignition key is in off position. Anything higher than 5 ohms means a short in the wirings.

Fix for 1997 Bonneville Security Light Problem:

I am still waiting for this ATS customer to give me the result of his tests. I supplied him the step by step instructions on testing this 1997 Bonneville Security light problem. Once he is finished, I will post the result here.

Notes:

Please refrain from doing this 1997 Bonneville Security light repair if you do not have any licensed mechanic to help you. Failure to do that can damage not only the anti theft decoder module but the engine computer itself.

Feel free to leave your comments below if you have any question.

Thanks,

Richard