Theory Of Operation

The family of B2100 Diagnostic Trouble Codes (DTCs) typically describes ignition performance related faults. These are often caused by a contradiction of switch status information. For example, if an Electronic Control Unit (ECU) receives a bussed message indicating ignition switch position but the state of a hardwired ignition circuit indicates another switch position a B2100 series DTC would likely result.

These DTCs can be caused by a number of conditions including:

• loose connections
• missing or blown fuses
• faulty component
• vehicle no start or long crank time

Verify the proper operation of the starting system and verify that this DTC is active before proceeding with the diagnostic test.