Passive Anti-Theft System (PATS) PIDs

Monitoring the IPC PATS PIDs can be very useful in determining which diagnostic steps to follow. Viewing the MASTERKEY PID (verifies if the key is programmed) (with both keys) determines if the key is a programmed key and proves-out the transceiver, circuitry and the IPC. A master key is any key that is programmed into the IPC. Viewing the MIN_KEYS PID (minimum number of keys) (this PID does not change) indicates the minimum number of keys that must be programmed into the IPC in order for the vehicle to start. There must be at least 2 keys programmed into the IPC in this type of PATS before the vehicle starts. Viewing the N_KEYCODE PID (number of keys registered in module) determines if the minimum number of keys has been programmed into the IPC. If the N_KEYCODE PID reads 0 or 1, additional key(s) need to be programmed into the IPC 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 IPC. If the N_KEYCODE PID reads 1, and the MASTERKEY PID reads Present, that particular key is already programmed into the IPC. The SPAREKEY (spare key) PID is defaulted to ENABLE.

When the parameters in the IPC are reset, it clears (erases) the PCM ID from the IPC. A PCM parameter reset causes the PCM to send a PCM ID to the IPC that is necessary for the system to operate. Make sure to cycle the key at least once, then turn the key ON and make an attempt to start the vehicle for 3-5 seconds before attempting more procedures. If only a PCM parameter reset occurs, the ID stored in the IPC does not match the ID being sent by the PCM, and can cause a PATS-related no-start. Carry out the parameter reset, and do not cycle the key until after the parameter reset selection has been highlighted, and the on-screen instructions have been followed. The IDS resets the parameters in both the IPC and the PCM at the same time.

If the PCM_ID reads Stored, the IPC has a PCM ID stored. If it reads Not Stored, a parameter reset may resolve this concern. If the PCM_VFY PID (PCM verify) reads No, the N_KEYCODE PID reads 2 or more and the MASTERKEY PID reads Present, the IPC, and the PCM need to have their parameters reset. Refer to PASSIVE ANTI-THEFT SYSTEM (PATS) PARAMETER RESET .

If the PCM_VFY PID reads NO, 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 IPC. Refer to INTEGRATED KEYHEAD TRANSMITTER (IKT) KEY PROGRAMMING USING DIAGNOSTIC EQUIPMENT .

The SPAREKEY PID is defaulted to ENABLE. With the SPAREKEY PID displaying ENABLE, the IPC accepts more than 2 keys (up to a maximum of 8) being programmed into the IPC using the Key Programming Using Two Programmed Keys  procedure. The SPAREKEY PID can be toggled to DISABLE if the customer wants to disable the customer spare key programming function. To enable or disable the spare key feature, refer to KEY PROGRAMMING SWITCH STATE CONTROL . This switch state control does not affect the IKT Key Programming Using Diagnostic Equipment procedure.

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

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