Normal Operation

The ignition switch receives fused battery voltage from the Body Control Module (BCM) permanent voltage bus through fuse 28 (15A). In the ACC or ON position, voltage is sent to the BCM. In the START position, voltage is sent to both the BCM and PCM.

When the ignition switch is cycled to the OFF/LOCK position from any other position, the BCM begins a monitoring cycle. The monitoring cycle checks that the voltage supplied to the BCM from the ignition switch through the RUN/ACC, RUN/START and START circuits is delivered correctly for each ignition switch position.

• DTC U300A:01 (Ignition Switch: General Electric Failure) - the BCM continuously monitors the ignition switch position. This DTC sets if the voltage inputs to the BCM do not match the pre-defined configurations for each ignition switch position.

This pinpoint test is intended to diagnose the following: 

• Fuse
• Wiring, terminals or connectors
• Ignition switch