Ignition ON Engine OFF mode
This mode is used to have all modules powered up and communicating on the serial data line. In order to achieve this mode the customer must have a valid key fob within the passenger compartment of the vehicle, the brake pedal depressed, and the transmission in Park or Neutral. Once that criteria is met, the customer must press and hold for 5 seconds the ACC/OFF portion of the Start/ACC/OFF mode button. The vehicle will power up with the engine OFF. A low transmitter battery or radio frequency (RF) interference from aftermarket devices such as 2-way radios, power inverters, cellular phone chargers, computers, etc. may cause a system malfunction. High RF traffic areas, such as gas stations which use pay-at-the-pump RF transponders, may also cause interference that could lead to a malfunction.