Passive Anti-Theft System (PATS) PIDs

WARNING: This page is about a different car, the 2010 Mercury Mariner and 2010 Ford Escape. However, it is still accessible from the selected car via links, so may be relevant.

Monitoring the PATS PIDs can be very useful in determining which diagnostic steps to follow. Viewing the MASTERKEY (verifies if the key is programmed) PID with both keys determines if the key is a programmed key and also proves-out the transceiver, circuitry and the IC . A master key is any key that is programmed into the IC . Viewing the MIN_KEYS (minimum number of keys) PID (this PID does not change) determines the minimum number of keys that must be programmed into the IC . There must be at least 2 keys programmed into the IC in this type of PATS before the vehicle starts. Viewing the N_KEYCODE (number of keys programmed) PID determines if the minimum number of keys have been programmed into the IC . If the N_KEYCODE PID reads 0 or 1, additional key(s) needs to be programmed into the IC in order to meet the minimum of 2 keys. If the N_KEYCODE PID reads 0 or 1, and the MASTERKEY PID reads Not Present, that particular key must be programmed into the IC . If the N_KEYCODE PID reads 1, and the MASTERKEY PID reads Present, that particular key is already programmed into the IC . If the IC is replaced, the parameters in the IC , and the parameters in the TCM need to be reset.

When the parameters are reset, it clears (erases) the TCM ID from the IC and the IC ID from the TCM . Make sure to cycle the key at least once, then turn the key to the ON position and make an attempt to start the vehicle for 3-5 seconds before attempting more procedures. If only a TCM parameter reset occurs (if a TCM is replaced), the ID stored in the IC does not match the ID being sent by the TCM , and can cause a PATS -related no-start. Carry out the parameter reset in order to resolve these concerns.

If the TCM ID PID (the scan tool displays the TCM ID as: PCM_ID) reads Stored, the IC has a TCM ID stored. If it reads Not Stored, a parameter reset of the TCM can resolve this concern. If the PCM_VFY PID reads No, and the N_KEYCODE PID reads 2 or more and the MASTERKEY PID reads Present, the IC , and the TCM need to have their parameters reset. Refer to PASSIVE ANTI-THEFT SYSTEM (PATS) PARAMETER RESET .

If the PCM_VFY PID reads No, and the N_KEYCODE PID reads 1 and the MASTERKEY PID reads Present, or if the N_KEYCODE PID reads 0 and the MASTERKEY PID reads Not Present, a minimum of 2 keys need to be programmed into the IC . Refer to INTEGRATED KEYHEAD TRANSMITTER (IKT) KEY PROGRAMMING USING DIAGNOSTIC EQUIPMENT .

If the MASTERKEY PID continues to read Not Present after programming, this can indicate a damaged key. The SPAREKEY PID is defaulted to ENABLE. With the SPAREKEY PID displaying ENABLE, the IC accepts more than 2 keys (up to a maximum of 8) being programmed into the IC using KEY PROGRAMMING USING TWO PROGRAMMED KEYS . It can be toggled to DISABLE if the customer wants to disable the customer spare key programming function. Refer to KEY PROGRAMMING SWITCH STATE CONTROL to change the state of the SPAREKEY PID. This switch state control affects the Key Programming Using Two Programmed Keys procedure.

In summary, for the vehicle to start, the PATS PIDs and their correct state are:

NOTE: The TCM ID PID in the IC is displayed by the Integrated Diagnostic System (IDS) scan tool as PCM_ID

N_KEYCODE must read 2 or more
MASTERKEY must read Present
PCM_ID must read Stored
PCM_VFY must read Yes