Why does my ignition module keep going out on my 2005 Bonneville?

If it were a anti-theft problem the engine would crank over and start for a couple seconds then die ! PCM - engine computer disables fuel injectors , not the starter like ford PATS systems . You need to know how the starter system works before you can repair them . And replacing parts isn't the way to do it . You people on here must have money to burn . Make parts stores rich .The ignition switch is a input to the BCM - body control module or body control system , made up of Three different modules .
The body control system consists of the following 3 modules:
• The dash integration module (DIM)
• The instrument panel integration module (IPM)
• The rear integration module (RIM)
Each of the 3 body control modules integrate a number of functional systems under the control of a single module. Each of the modules are connected to the Class 2 serial data line; many control signals are implemented by Class 2 messages.
The DIM is wired to the class 2 serial data line. The various DIM input and output circuits are described in the corresponding functional areas as indicated on the DIM electrical schematics.
The DIM functions include the following:
• Control of headlights and exterior lamps
• Horn relay control
• Interior lamps incandescent dimming
• Lamps On signal with wiper/washer
• Power moding control over Class 2 serial data line
• Steering wheel controls
• Storage of the clock settings and, sending a message out on the class 2 serial data circuit in response to requests from other modules
Serial Data Power Mode
On vehicles that have several control modules connected by serial data circuits, one module is the power mode master (PMM). On this vehicle the PMM is the DIM. The PMM receives 4 signals from the ignition switch.
To determine the correct power mode the PMM uses the following circuits:
• Accessory voltage
• Ignition 1 voltage
• Ignition 3 voltage
• Off/Run/Crank voltage
Your best bet is to take your vehicle to a qualified repair shop that has the tool and the factory service repair manual .

Starter switch ? You do mean ignition switch , the thing on the dash or steering column that you stick the key in ! You car not starting ? The ignition switch isn't the same anymore , sends Discrete Ignition Signals to a module ,in the case of your vehicle it is the DIM - dash integrated module.
The body control system consists of the following 3 modules:
?€¢
The dash integration module (DIM)

?€¢
The instrument panel integration module (IPM)

?€¢
The rear integration module (RIM)

Each of the 3 body control modules integrate a number of functional systems under the control of a single module. Each of the modules are connected to the Class 2 serial data line; many control signals are implemented by Class 2 messages.
On vehicles that have several control modules connected by serial data circuits, one module is the power mode master (PMM). On this vehicle the PMM is the DIM. The PMM receives 4 signals from the ignition switch.
To determine the correct power mode the PMM uses the following circuits:
?€¢
Accessory voltage

?€¢
Ignition 1 voltage

?€¢
Ignition 3 voltage

?€¢
Off/Run/Crank voltage

Your best bet would be to take to a repair shop that has knowledge of this type system . You probably don't need an ignition switch.
Discrete Ignition Signals Those modules that have discrete ignition signal inputs also remain in the state dictated by the last valid PMM message received on the serial data circuits. They then check the state of their discrete ignition input to determine the current valid state. If the discrete ignition input is active, battery positive voltage, the modules will fail-safe to the RUN power mode. If the discrete ignition input is not active, open or 0 voltage, the modules will fail-safe to OFF-AWAKE. In this state the modules are constantly checking for a change status message on the serial data circuits and can respond to both local inputs and serial data inputs from other modules on the vehicle.

Replace the ignition module.

I’m happy to help further over the phone at https://www.6ya.com/expert/michael_195f36f311cb10df

Did you have the vehicle's control module system checked for DTC'S - diagnostic trouble code's ??????? Specifically the SJB - smart junction box , ford's BCM - body control module . Does the remote start/keyless entry still work ? Adding after maket system's to vehicle's (even your year ) isn't all ways a good ideal . It can cause major problems ! Having a qualified professional automotive technician check it out would be a good idea. Who installed these aftermarket systems ? Some of these place's have no idea what they are hooking to , any old place they can find B+ power .

P0420 is the cataylic convertor code it being less then 50%efficant but its not the problem i think you have a weak spark I would look at the coil that could be damageing the ignition module

Here you go!

Under the coil pack, there is an ignition module.
Have a look to this link.


https://easyautodiagnostics.com/gm/3.8L/ignition-coil-pack-tests-1

Hope it helps.

sounds like the ignition module is going bad.

Check the ignition module. The coils plug directly on to it, it should be silver in color and about 1/4-1/2" thick.

call a locksmith they have a reader and can tell if your key is the problem... it will tell them which keycode is for your vehicle and they can check and see if the key matches also i have a 95 ssei and the pcm was the problem with mine