Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
Ignition Switch System: Start
When the ignition switch is placed in the START position, the switch routes voltage through the ON-designated and START-designated circuits to the BCM.
The BCM interprets this as the ignition start mode and communicates the ignition mode to the other modules by sending an ignition status message over the CAN. Additionally, the ignition switch routes voltage to the PCM indicating a request to start the vehicle.
The START-designated circuit is only used for vehicle starting.
NO RELATED
Use the Manual With the Right Hardware
Pair factory procedures with proven DIY tools so the instructions are easier to execute.
Affiliate disclosure: We may earn a commission at no extra cost to you.
When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- • You smell fuel, burning insulation, or see smoke.
- • Brakes feel soft, pull hard to one side, or make grinding noises.
- • The engine overheats, stalls repeatedly, or misfires under load.
- • You are missing required tools, torque specs, or safe lifting equipment.
- • You are not confident in the next step or safety outcome.