The Idle Validation Switch is open at the idle position and transmits no voltage to the (VECU) Vehicle Electronic Control Unit. At approximately 1-13% pedal position the Idle Validation Switch closes and completes the circuit to the (VECU) Vehicle Electronic Control Unit.
The (VECU) Vehicle Electronic Control Unit then sends a voltage signal to the Engine Control Module (ECM) indicating accelerator pedal position. If both communication links (J1939, J1587) are faulty the pedal demand functionality enters limp-home. During limp-home the (IVS) Idle Validation Switch is used for ramping requested torque.

Conditions for diagnostic trouble code (DTC):
1) Accelerator pedal pressed down more than 50?%
2) Short circuit to ground on A14.EB:15
3) Open circuit between ECM: Engine Control Module (ECM) and Vehicle Control Unit (VECU)

Observable symptoms
1) The limp home mode does not function
2) Yellow check lamp illuminated

Probable cause
1) Open circuit on signal wire
2) Connector
3) Accelerator pedal
4) Engine control module (ECM)