Normal Operation - Vehicles equipped with a CDIM

The ignition switch and the CDIM  work together to distribute fused battery voltage to the SJB  , BJB  , run/start relay and starter relay depending on the current ignition switch position. When the ignition switch is placed in the ACC or START position, the CDIM  is in a passive state allowing the voltage to simply pass through the module using normally-closed relays. When the ignition switch is placed in the RUN position the CDIM  becomes active. While active, the CDIM  will still allow ignition voltage to pass through the internal relays, but it will also start monitoring the Medium Speed Controller Area Network (MS-CAN) bus for messages. Once the voltage passes through the CDIM  , it returns to the ignition switch and then out to various systems depending on ignition switch position. The ignition switch has 4 positions:

• OFF - Power on circuit CDC30 (BU/GY) to the SJB  for key-in ignition chime
• ACC - Power on circuit CDC33 (VT/GN)
• RUN - Power on circuits CDC32 (BN/YE), CDC33 (VT/GN), CDC34 (WH/OG) and CDC63 (YE/OG)
• START - Power on circuit CDC35 (BU/WH) and CDC34 (WH/OG)

  This pinpoint test is intended to diagnose the following: 

• Fuse
• Wiring, terminals or connectors
• Ignition switch
• SJB 
• CDIM