Push Button Start Operation

Fig 1: Push Button Start Communication Diagram

Courtesy of FORD MOTOR CO.

NOTE: The IA feature is a programmable parameter and can be enabled/disabled with a scan tool. If the feature is disabled, the Intelligent Access (IA) feature to enter the vehicle and passive starting will be inoperative. To start the vehicle, the IA key has to be placed in the backup slot. Refer to MODULE CONFIGURATION for information on enabling/disabling the IA feature.

The Passive Anti-Theft System (PATS) function is controlled by the RFA module, BCM , and PCM.

When the start/stop switch is pressed, the RFA module initiates the key initialization sequence by activating the 3 interior IA passive start antennas. Each passive start antenna transmits a low frequency signal approximately 1 m (3 ft) radius of each antenna. If an IA key is within range of 1 of the 3 interior passive start antennas, the IA key is activated. Once the IA key is activated, it sends the PATS identification code to the TPM module via a high frequency signal. The TPM module interprets the high frequency signal from the IA key and sends the information to the RFA module over a dedicated network. If the RFA module determines that a programmed IA key is inside the vehicle, it communicates with the BCM over the MS-CAN and allows the ignition to be transitioned out of off. When the ignition is turned on and the modules initialize, the RFA module, BCM , and the PCM exchange their IDs over the MS-CAN and High Speed Controller Area Network (HS-CAN). If each of the modules receive the correct ID from each other, PATS is enabled and allows the engine to start. If PATS disables the engine from starting, STARTING SYSTEM FAULT is displayed in the message center and a DTC is stored in one of the 3 modules.

PATS and the RKE system share the operation of several components including the IA key and the TPM module. If there is a concern with either of these components, both PATS and the RKE system are affected. Refer to HANDLES, LOCKS, LATCHES AND ENTRY SYSTEMS for information on the RKE and IA features.

The RFA module in conjunction with the BCM controls the ignition modes and in conjunction with the PCM controls the starting system. If there is a concern with the starting system or the ignition modes, and PATS has been eliminated as the cause, refer to STARTING SYSTEM for a starting system concern or STEERING COLUMN SWITCHES for the ignition modes.