Network Message Chart - Conventional Ignition Switch: Start

When the BCM  receives the ON voltage input from the ignition switch (also present in the START position), it activates the ignition relay, providing ignition power to various vehicle systems and modules. The PCM  communicates the state of the engine by sending an "engine state" and "power pack status" message over the High Speed Controller Area Network (HS-CAN) to the BCM  . While the engine is cranking, the BCM  inhibits the accessory relay. The BCM  communicates the state of the ignition to the other modules by sending an "ignition status" message over the Medium Speed Controller Area Network (MS-CAN).

The ignition switch START circuit is hardwired to the PCM  . The PCM  uses the ignition switch START input to determine when to activate the starter motor relay. For information on the starting system:

• Refer to: STARTING SYSTEM - VEHICLES WITH: KEYLESS ENTRY AND PUSH BUTTON START - OVERVIEW .
• Refer to: STARTING SYSTEM - OVERVIEW .