Ford Taurus Service Manual: Anti-Theft - Passive Anti-Theft System (PATS), Without Intelligent Access (IA)

DESCRIPTION AND OPERATION

Anti-Theft

Overview

PATS deters the vehicle from theft by preventing the engine from starting unless a programmed PATS key is in the ignition. PATS does not disable an already running engine.

System Operation

System Diagram

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Network Message Chart

 PCM Network Input Messages

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 BCM Network Input Messages

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Passive Anti-Theft System (PATS)

The PATS function is controlled by the BCM. There are 2 main checks that PATS performs before allowing the engine to start. If either of these checks fail, PATS does not allow the engine to start and STARTING SYSTEM FAULT displays in the message center. These 2 checks are the BCM verifying the PCM identification to make sure it matches the PCM identification stored in memory and to verify that a programmed key was used to change the ignition to RUN or START.

The first check is initiated by the BCM waking up the PCM by supplying voltage on the wakeup control circuit. The BCM only activates the wakeup circuit 5 times. After that, the wakeup circuit remains off until the ignition is cycled to RUN. The BCM activates the wakeup control circuit when any of the following occur:

  • The driver door is opened
  • A remote start request is received (if equipped with factory remote start)
  • The brake pedal is applied
  • A key is inserted into the ignition key cylinder
  • The ignition transitions to RUN or START

Once the PCM is awake, the BCM sends the PCM a challenge message over the HS-CAN. When the PCM receives the challenge message, it generates a response and sends it back to the BCM. If the response from the PCM does not match the response in the BCM memory, this first check fails and the engine does not start.

Once the PCM identification has been verified, PATS performs the second check to make sure a programmed key is in the ignition key cylinder. When the BCM determines the ignition changes to RUN or START, it generates a challenge message. It sends the challenge message to the PATS transceiver on the transmit (TX) circuit. The transceiver in turn reads the key and generates a response message that is sent back to the BCM on the receive (RX) circuit. If the message received from the transceiver does not match a key stored in the BCM memory, the engine does not start.

If both the PCM identification and key verification pass, PATS allows the engine to start. PATS cannot disable or stall an engine that has already been started.

PATS PIDs

In conjunction with DTCs, the PATS PIDs are a useful tool when diagnosing PATS concerns.

BCM Module PID Chart

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Unlimited Key Mode

PATS contains a feature called unlimited key mode. This feature allows a customer to program more than 8 keys to their vehicle, if requested. Each vehicle in unlimited key mode is set up with a special unlimited transponder security key code. This allows all of the customer vehicles to share the same mechanically cut keys. For an individual customer, any randomly selected security key that has been previously mechanically cut and electronically programmed to the vehicle is acceptable. To enable/change the unlimited key mode, refer to Key Programming - Unlimited Key Mode.

When in the unlimited key mode, the KEYS_PROGMD PID in the BCM always reads 2, no matter how many keys are programmed to the vehicle (after the first 2 keys have been programmed to the vehicle).

Component Description

Integrated Keyhead Transmitter (IKT)

NOTE: The IKTs must have SA stamped on the keyblade. Conventional PATS keys must have HA or SA stamped on the keyblade.

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The IKT incorporates both the PATS functions and the RKE transmitter functions in a single device.

During key programming procedures, the PATS and RKE transmitter of an IKT are both programmed into the BCM. Conventional PATS keys can also be programmed to the vehicle if requested by the customer.

Up to a maximum of 4 IKTs can be programmed. If more than 4 IKTs are programmed, INT KEY COULD NOT PROGRAM displays in the message center during the key programming procedure and the RKE functions of that IKT are inoperative.

Passive Anti-Theft System (PATS) Transceiver

The PATS transceiver reads any key that is placed in the ignition. When the ignition changes to ON or START, the BCM activates the PATS transceiver. Once the transceiver is activated, it in turn activates the key in the ignition and receives the key data. Once the transceiver receives the key data, it sends the data to the BCM.

DIAGNOSIS AND TESTING

Anti-Theft

DTC Charts

Diagnostics in this manual assume a certain skill level and knowledge of Ford-specific diagnostic practices. Refer to Diagnostic Methods in Section 100-00 for information about these practices.

BCM DTC Chart

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PCM DTC Chart

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Symptom Chart

Diagnostics in this manual assume a certain skill level and knowledge of Ford-specific diagnostic practices. Refer to Diagnostic Methods in Section 100-00 for information about these practices.

Symptom Chart: Passive Anti-Theft System (PATS)

Ford Taurus. Electronic Feature Group

Pinpoint Tests

Pinpoint Test A: The Engine Does Not Start

Diagnostic Overview

Diagnostics in this manual assume a certain skill level and knowledge of Ford-specific diagnostic practices. Refer to Diagnostic Methods in Section 100-00 for information about these practices.

Normal Operation and Fault Conditions

Refer to System Operation - Passive Anti-Theft System (PATS) in Anti-Theft.

Refer to Component Description - Integrated Keyhead Transmitter (IKT) in Anti-Theft.

Refer to Component Description - Passive Anti-Theft System (PATS) Transceiver in Anti-Theft.

    Possible Sources:
  • Driveability system concern
  • Starting system concern
  • PATS concern

PINPOINT TEST A: THE ENGINE DOES NOT START

Ford Taurus. Electronic Feature Group

Pinpoint Test B: B10D7:05

Diagnostic Overview

Diagnostics in this manual assume a certain skill level and knowledge of Ford-specific diagnostic practices. Refer to Diagnostic Methods in Section 100-00 for information about these practices.

Normal Operation and Fault Conditions

When the BCM enters a key programming state, it activates the transceiver to read the key in the ignition key cylinder. If a valid PATS key is used and there are no concerns with the PATS, the key is programmed into the BCM memory.

BCM DTC Fault Trigger Conditions

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    Possible Sources:
  • PATS key not programmed

Visual Inspection and Diagnostic Pre-checks

  • Inspect the PATS key for damage.
  • Verify the correct key is used.

PINPOINT TEST B: B10D7:05

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Pinpoint Test C: B10D7:87 or B10D7:8F

Diagnostic Overview

Diagnostics in this manual assume a certain skill level and knowledge of Ford-specific diagnostic practices. Refer to Diagnostic Methods in Section 100-00 for information about these practices.

Normal Operation and Fault Conditions

When the ignition transitions to RUN or START, the BCM activates the transceiver to read the key in the ignition key cylinder. If the BCM does not receive a PATS key code or if the code is invalid, the PATS does not allow the engine does not start.

BCM DTC Fault Trigger Conditions

Ford Taurus. Electronic Feature Group

    Possible Sources:
  • PATS key
  • PATS transceiver

Visual Inspection and Diagnostic Pre-checks

  • Inspect the PATS key for damage.
  • Verify the correct key is used.

PINPOINT TEST C: B10D7:87 OR B10D7:8F

NOTE: This pinpoint test requires a second programmed PATS keys. If only one key is available, a second programmed PATS key must be obtained.

Ford Taurus. Electronic Feature Group

Pinpoint Test D: B10D9:87

Diagnostic Overview

Diagnostics in this manual assume a certain skill level and knowledge of Ford-specific diagnostic practices. Refer to Diagnostic Methods in Section 100-00 for information about these practices.

Refer to Wiring Diagrams Cell 112, Passive Anti-Theft System for schematic and connector information.

Normal Operation and Fault Conditions

The BCM supplies voltage to the PATS transceiver. When the ignition changes to RUN or START, the BCM initiates the key interrogation sequence. The BCM starts the interrogation sequence by generating a signal and sending that signal to the transceiver on the transmit (TX) circuit. When the transceiver receives the signal from the BCM, it reads the PATS key and generates a challenge response to the BCM signal. The transceiver sends the challenge response back to the BCM on the receive (RX) circuit.

BCM DTC Fault Trigger Conditions

Ford Taurus. Electronic Feature Group

    Possible Sources:
  • Fuse
  • Wiring, terminals or connectors
  • PATS transceiver
  • BCM

Visual Inspection and Diagnostic Pre-checks

  • Verify the BCM fuse 18 (10A) is OK.

PINPOINT TEST D: B10D9:87

NOTICE: Use the correct probe adapter(s) when making measurements. Failure to use the correct probe adapter(s) may damage the connector.

Ford Taurus. Electronic Feature Group

Ford Taurus. Electronic Feature Group

Ford Taurus. Electronic Feature Group

Ford Taurus. Electronic Feature Group

Pinpoint Test E: C113A:11 or C113A:15

Diagnostic Overview

Diagnostics in this manual assume a certain skill level and knowledge of Ford-specific diagnostic practices. Refer to Diagnostic Methods in Section 100-00 for information about these practices.

Refer to Wiring Diagrams Cell 112, Passive Anti-Theft System for schematic and connector information.

Normal Operation and Fault Conditions

The wakeup control circuit wakes up the PCM prior to engine cranking. The PCM needs to wake up prior to a crank request so that it has time to go through its initialization. The wakeup control circuit also powers the PATS transceiver. The wakeup control circuit is controlled by the BCM. The wakeup control circuit is FET protected.

The BCM activates the wakeup control circuit when:

  • the driver door is opened,
  • a remote start request is received (if equipped with factory remote start),
  • the brake pedal is applied,
  • a key is inserted into the ignition key cylinder, or
  • the ignition is in RUN or START.

BCM DTC Fault Trigger Conditions

Ford Taurus. Electronic Feature Group

    Possible Sources:
  • Wiring, terminals or connectors
  • PATS transceiver
  • BCM
  • PCM

Visual Inspection and Diagnostic Pre-checks

  • Verify the BCM fuse 18 (10A) is OK.

PINPOINT TEST E: C113A:11 OR C113A:15

Ford Taurus. Electronic Feature Group

Ford Taurus. Electronic Feature Group

Ford Taurus. Electronic Feature Group

Ford Taurus. Electronic Feature Group

Ford Taurus. Electronic Feature Group

GENERAL PROCEDURES

Enable or Disable Spare Key Programming

NOTE: This procedure provides the capability to enable/disable the normal customer spare key programming procedure detailed in the Owner's Literature and the Key Programming Using Two Programmed Keys procedure. If spare key programming is disabled, spare keys can only be programmed by using the scan tool. REFER to Key Programming Using Diagnostic Equipment.

  1. Turn the ignition key cylinder from OFF to RUN.
  1. From the scan tool, enter TOOLBOX. Select Body>Security>PATS Functions and follow the IDS on-screen instructions to enter PATS security access.
  1. From the scan tool menu, select "Customer Spare Key Programming Enable" or "Customer Spare Key Programming Disable" and follow the IDS on-screen instructions.

Erase All Keys and Program Two Keys

General Procedure

NOTE: This procedure erases all programmed ignition keys from the vehicle memory. The vehicle cannot start until a minimum of 2 keys are programmed into the BCM-B.

NOTE: Two PATS keys with the correct mechanical cut must be available to carry out this procedure.

NOTE: This procedure erases all MyKey features on all of the keys that are programmed to the vehicle. All of the keys then operate as normal (admin) keys with no restrictions.

  1. Turn the key from the OFF position to the ON position.
  1. From the scan tool, enter TOOLBOX. Select Body>Security>PATS Functions and follow the IDS on-screen instructions to enter PATS security access.
  1. From the scan tool menu, select "Ignition Key Code Erase" and follow the IDS on-screen instructions until the key erase procedure completes. The scan tool then instructs you to program 2 keys to complete the process.
  1. Turn the key to the OFF position and disconnect the scan tool (the key does not need to be removed from the ignition at this time).
  1. NOTE: The doors lock and then unlock to confirm that each IKT is programmed.

    Turn the first PATS key to the RUN position for a minimum of 6 seconds.

  1. Turn the first PATS key to the OFF position and remove the key from the ignition.
  1. Insert the second PATS key into the ignition and turn the key to the RUN position for a minimum of 6 seconds.
  1. The engine should now start with both PATS keys.
  1. If it is desired to program additional keys, refer to Key Programming Using Two Programmed Keys for each additional key that needs to be programmed.
    1. A total of 8 PATS keys can be programmed into the BCM-B. Of those 8 keys, a maximum of 4 IKTs can be programmed.

Key Programming - Unlimited Key Mode

Enable

NOTE: When in the unlimited key mode, the KEYS_PROGMD PID in the BCM always reads 2, regardless of how many keys are programmed to the vehicle (after the first 2 keys have been programmed to the vehicle).

NOTE: If the BCM PID UNL_KEY_ID is not available, unlimited key mode is turned on and must be turned off before viewing the stored code. At this time, unlimited keys may be programmed to the vehicle. To view/disable/change the stored code, follow the procedure below for disabling the unlimited key mode.

  1. The customer must choose an 8-digit number (except for 00000000, 00000001, or FFFFFFFF) to be programmed to all of their vehicles or to all of the keys for one vehicle. Valid digits are 0-9 and the letters A-F.
  1. From the scan tool, enter TOOLBOX. Select Body>Security>PATS Functions and follow the IDS on-screen instructions to enter PATS security access.
  1. Once in security access, select "unlimited key mode ON" and follow the IDS on-screen instructions.
  1. Select "program unlimited key code" and follow the IDS on-screen instructions. Enter the 8-digit code chosen by the customer in step 1 of this procedure and follow the IDS on-screen instructions.
  1. Select "Ignition Key Code Erase" and follow the IDS on-screen instructions.
  1. Turn the key to OFF and disconnect the scan tool (the key does not need to be removed from the ignition at this time).
  1. Turn the first PATS key to RUN for a minimum of 3 seconds.
  1. Turn the first PATS key to OFF and remove the key from the ignition key cylinder.
  1. Insert the second PATS key into the ignition key cylinder and turn the ignition key cylinder to RUN for a minimum of 3 seconds.
  1. The engine should now start with either PATS key.
  1. If it is desired to program additional key(s), REFER to Key Programming Using Two Programmed Keys.

Disable

  1. From the scan tool, enter TOOLBOX. Select Body>Security>PATS Functions and follow the IDS on-screen instructions to enter PATS security access.
  1. Select "unlimited key mode OFF" and follow the IDS on-screen instructions.
  1. Select "Ignition Key Code Erase" and follow the IDS on-screen instructions.
  1. Turn the key to OFF and disconnect the scan tool (the key does not need to be removed at this time).
  1. Turn the first PATS key to RUN for a minimum of 3 seconds.
  1. Turn the first PATS key to OFF and remove the key from the ignition key cylinder.
  1. Insert the second PATS key into the ignition key cylinder and turn the ignition key cylinder to RUN for a minimum of 3 seconds.
  1. The engine should now start with either PATS key.
  1. If it is desired to program additional key(s) (a total of 8 keys can be programmed into the BCM ), REFER to Key Programming Using Two Programmed Keys.

Key Programming Using Diagnostic Equipment

NOTE: If 8 keys are already programmed, this procedure does not allow any more PATS keys to be programmed without erasing all stored key codes first.

  1. Insert the unprogrammed PATS key into the ignition key cylinder and turn the ignition key cylinder to RUN.
  1. From the scan tool, enter TOOLBOX. Select Body>Security>PATS Functions and follow the IDS on-screen instructions to enter PATS security access.
  1. From the scan tool menu select "Program additional ignition key" and follow the IDS on-screen instructions.
  1. The engine should now start with the new PATS key.

Key Programming Using Two Programmed Keys

NOTE: This procedure works only if 2 or more programmed keys are available. If 2 programmed keys are not available, refer to Key Programming Using Diagnostic Equipment.

NOTE: This procedure works only if the customer spare key programming is enabled. If the customer spare key programming is disabled, REFER to Enable or Disable Spare Key Programming or Key Programming Using Diagnostic Equipment.

  1. Insert the first programmed PATS key into the ignition key cylinder and turn the ignition key cylinder to RUN (maintain the key in RUN for approximately 3 seconds).
  1. Turn the first key to OFF and remove the key from the ignition key cylinder.
  1. Within 10 seconds of turning the first key to OFF, insert a second programmed PATS key into the ignition key cylinder and turn the key to RUN (maintain the key in RUN for approximately 3 seconds).
  1. Turn the second key to OFF and remove the key from the ignition key cylinder.
  1. NOTE: The doors lock and then unlock to confirm that each IKT is programmed.

    Within 10 seconds of turning the second key to OFF, insert the new, unprogrammed PATS key into the ignition key cylinder and turn the ignition key cylinder to RUN (maintain the key in RUN for approximately 6 seconds).

  1. If it is desired to program additional keys, repeat Steps 1-5 for each additional key.
    • A total of 8 PATS keys can be programmed into the BCM. Of those 8 keys, a maximum of 4 IKTs can be programmed.

Passive Anti-Theft System (PATS) Parameter Reset

  1. Turn the key from OFF to RUN.
  1. From the scan tool, enter TOOLBOX. Select Body>Security>PATS Functions and follow the IDS on-screen instructions to enter PATS security access.
  1. NOTE: If the BCM was replaced, at least 2 keys must be programmed to the BCM. After completing step 3, leave the scan tool connected and REFER to Erase All Keys and Program Two Keys.

    From the scan tool, select "Parameter Reset" and follow the IDS on-screen instructions.

REMOVAL AND INSTALLATION

Passive Anti-Theft System (PATS) Transceiver

Ford Taurus. Electronic Feature Group

Ford Taurus. Electronic Feature Group

Removal and Installation

  1. Pulling firmly upward, remove the LH upper rail panel.
  1. Disconnect the Passive Anti-Theft System (PATS) transceiver electrical connector.
  1. Using a suitable tool (such as a dentist pick), release the tabs and remove the PATS transceiver.
  1. NOTE: Replacement of the PATS transceiver does not require the PATS keys to be programmed into the Instrument Panel Cluster (IPC) again.

    To install, reverse the removal procedure.

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