Passive Anti-Theft System (PATS) - System Operation and Component Description

System Operation

System Diagram

Network Message Chart

  BCM Network Input Messages

  IPC Network Input Messages

  PCM / SOBDMC Network Input Messages

PATS

The PATS function is controlled by the BCM and the PCM / SOBDMC .

When the START/STOP button is pressed, a voltage signal is sent to the BCM . When the BCM detects the START/STOP button is pressed, it begins the key initialization sequence by activating the PATS center antenna, the keyless entry rear antenna and both exterior door handle keyless entry antennas. Each antenna transmits a low frequency signal with an approximate range of 1 m (3 ft). The passive key activates if it is within range of the antennas. The BCM is able to determine the passive key location (inside or outside the vehicle) based on the input from the antennas.

When the passive key activates, it sends the PATS identification code to the RTM via a high frequency signal. The RTM interprets the high frequency signal from the passive key and sends the information to the BCM over the LIN -based circuit.

If a programmed passive key is detected inside the vehicle, the BCM transitions the ignition out of off.

When the ignition transitions out of off and the modules initialize and the PCM / SOBDMC sends a challenge request to the BCM . The BCM replies and if the correct identification is received, the PATS disables and allows the vehicle to start. If the PATS prevents the vehicle from starting, a DTC sets in one of the modules.

The PATS and the RKE system share operation of several components including the passive keys, the exterior front door handle antennas, the PATS center antenna, the keyless entry rear antenna and the RTM .

If there is a concern with any of these components, the PATS and the RKE system are both affected.

The vehicle can experience a PATS no start if a failure occurs with:

• the PATS center antenna.
• the keyless entry rear antenna.
• an exterior door handle keyless entry antenna.
• the battery in the passive key.
• the RTM .
• the BCM .
• the PCM / SOBDMC .

In the event of one of these failures, place a programmed passive key in the backup location to allow the vehicle to start. The PATS center antenna activates the passive key when the START/STOP button is pressed.

The BCM controls the ignition modes and, in conjunction with the PCM / SOBDMC , control the PATS .

For information on ignition states,
Refer to: Steering Wheel and Column Electrical Components - System Operation and Component Description (211-05 Steering Wheel and Column Electrical Components, Description and Operation).

PATS Parameter Identifications (PIDs)

In conjunction with Diagnostic Trouble Codes (DTCs), the PATS Parameter Identifications (PIDs) are a useful tool when diagnosing PATS concerns.

  BCM PID Chart

  PCM / SOBDMC PID Chart

Backup Starting

NOTE: There are certain areas within the vehicle where the passive key may not be detected and the message center displays No Key Detected. If the passive key is in the far outside edges of the interior (such as in a door map pocket or above a sun visor), it may not be detected. Move the passive key to a different location and try to turn the ignition on.

When the vehicle experiences a PATS condition, the No Key Detected message displays in the message center when the START/STOP button is pressed.

In the event of one of these failures, place a programmed passive key in the backup location to allow the vehicle to start. When the START/STOP button is pressed, the center PATS antenna activates the passive key and the identification code is sent to the BCM . The backup location is located in the floor console.
Refer to: Passive Anti-Theft System (PATS) - Component Location (419-01C Passive Anti-Theft System (PATS) - Vehicles With: Push Button Start, Description and Operation).

No Key Detected Message

NOTE: Some brands/types of mobile phone or laptop computer chargers may cause interference that could lead to a PATS concern if the passive key is within close proximity of the charger. If a concern is observed, move the passive key away from the charger and attempt to turn the ignition on.

There are 2 scenarios in which the No Key Detected message displays in the message center.

The first is when the ignition is off, the START/STOP button is pressed and a programmed passive key is not detected inside the vehicle. If a component failure (such as a dead passive key battery) is causing the No Key Detected message to display, the backup starting method can be used.

The second scenario is when the vehicle is running, the driver exits the vehicle with the programmed passive key and closes the door.

The BCM activates the center PATS antenna, the keyless entry rear antenna and both exterior door handle keyless entry antennas to search the inside of the vehicle for a passive key any time a door or the luggage compartment lid is opened and then closed with the vehicle running and the first times each drive cycle the vehicle speed exceeds 15 kp/h (9 mph). The No Key Detected message displays in the message center and the horn chirps twice when the ignition is on and a passive key is no longer detected inside the vehicle.

This strategy deters the passive key from being separated from an already running vehicle. If a passive key is no longer in the vehicle, the ignition remains on and the vehicle continues to operate. When the START/STOP button is pressed to turn the ignition off, the ignition can be restarted without a passive key present inside the vehicle for approximately 20 seconds. After 20 seconds have elapsed, a passive key must be present to transition the ignition out of off.

Automatic Engine Idle Shutdown

The automatic engine idle shutdown feature monitors the state of the vehicle to determine when the engine is powered with no user interaction for approximately 30 minutes. Approximately 30 seconds prior to the shutdown, a message displays in the message center to inform the operator a vehicle shutdown is imminent. This includes shutting down the engine and turning the ignition off. When the shutdown occurs, press the brake and START/STOP button to re-start the vehicle.

The conditions required to begin the automatic engine idle shutdown feature are:

• power pack enabled
  • engine running (non-hybrid vehicles)
  • engine running or auto stop mode active (hybrid vehicles)
• brake pedal not pressed
• accelerator pedal not pressed
• remote start not active
• transmission in P (park) or N (neutral)
• diagnostic scan tool not connected to the vehicle

Once these conditions are met, a time-out starts. When the time-out period ends and none of the listed conditions changed, the automatic engine idle shutdown event occurs.

Component Description

Passive Key

The passive key incorporates both the PATS and the RKE transmitter functions in a single device. The passive key must be located inside the vehicle for the ignition to transition out of off and on the outside for keyless entry features. During key programming procedures, the PATS and the RKE transmitter of the passive key are both programmed into the BCM . The vehicle accepts programming of up to 4 passive keys.

The passive key receives the low frequency signals from the PATS center antenna and the keyless entry rear antenna. When the passive key is activated by one of the low frequency signals, it sends out a high frequency signal that is received by the RTM . The passive key also contains a removable key blade that unlocks the driver door in the event of an electrical failure (such as a drained battery).

PATS Center Antenna

NOTE: Some brands/types of mobile phone or laptop computer chargers may cause interference that could lead to a PATS concern if the passive key is within a few inches of the charger and the No Key Detected message displays in the message center. If a concern is observed, move the passive key away from the charger and attempt to transition the ignition on.

The PATS center antenna wired to the BCM . When activated by the BCM , it transmits a low frequency signal that activates a passive key. This antenna serves a dual purpose in that it can detect a passive key in the backup starting location. The backup starting location is used to program passive keys and to detect a programmed passive key in the event the battery in the programmed passive key has failed.

When activated, the PATS center antenna sends out a low frequency signal with an approximate range of 1 m (3 ft). A programmed passive key must be within range for the PATS to operate.

If a passive key is placed in the far outside edges of the interior, such as above a sun visor or in a door map pocket, the vehicle can experience a PATS concern. If the passive key is located in one of these areas and there is a PATS concern, move the passive key out of the area and attempt to transition the ignition on. If the key is outside the range of the PATS center antenna and the keyless entry rear antenna when the START/STOP button is pressed, the No Key Detected message displays in the message center.

Keyless Entry Rear Antenna

NOTE: Some brands/types of mobile phone or laptop computer chargers may cause interference that could lead to a PATS concern if the passive key is within a few inches of the charger and the No Key Detected message displays in the message center. If a concern is observed, move the passive key away from the charger and attempt to transition the ignition on.

The keyless entry rear antenna is wired to the BCM . When activated by the BCM , it transmits a low frequency signal that activates a passive key.

When activated, the keyless entry rear antenna sends out a low frequency signal with an approximate range of 1 m (3 ft). A programmed passive key must be within range for the PATS to operate.

If a passive key is placed in the far outside edges of the interior, such as the far corners of the luggage compartment, the vehicle can experience a PATS concern. If the passive key is located in one of these areas and there is a PATS concern, move the passive key out of the area and attempt to transition the ignition on. If the key is outside the range of the keyless entry rear antenna and the center PATS antenna when the START/STOP button is pressed, the No Key Detected message displays in the message center.

Exterior Front Door Handles

The exterior door handles contain a keyless entry antenna. The antennas are wired to the BCM . When activated by the BCM , the antenna transmits a low frequency signal with an approximate range of 1 m (3 ft) to activate a passive key.

A programmed passive key must be within range for the PATS to operate.

If a passive key is placed in the far outside edges of the interior, such as the far corners of the luggage compartment, the vehicle can experience a PATS concern. If the passive key is located in one of these areas and there is a PATS concern, move the passive key out of the area and attempt to transition the ignition on. If the key is determined by the BCM to be outside the vehicle or is outside the range of the antennas within the exterior front door handles, the keyless entry rear antenna and the front PATS antenna when the START/STOP button is pressed, the No Key Detected message displays in the message center.

BCM

If the BCM is replaced, program at least 2 keys and perform the parameter reset procedure.

PCM / SOBDMC

When the PCM / SOBDMC is replaced, perform the parameter reset procedure. There is no need to program keys if the PCM / SOBDMC is replaced.

Copyright © Ford Motor Company