PATS Parameter Identification (PIDs)

Monitoring the PATS PIDs can be very useful in determining which diagnostic steps to follow. Viewing the MASTERKEY (master key) PID (with both keys) will determine if the key is a programmed key and will also prove out the transceiver, circuitry and the PCM. A master key is any key that is programmed into the PCM. Viewing the MIN_KEY (minimum number of keys) PID (this PID does not change) determines the minimum number of keys that must be programmed into the PCM. There must be at least 2 keys programmed into the PCM in this system. Viewing the N_KEYCODE (number of keys programmed) PID will determine if the minimum number of keys have been programmed into the PCM. If the N_KEYCODE PID reads 0 or 1, additional key(s) will need to be programmed into the PCM in order to meet the minimum of 2 keys. If the N_KEYCODE PID reads 0 or 1, and the MASTERKEY PID reads NOTPREST, that particular key must be programmed into the PCM. If the N_KEYCODE PID reads 1, and the MASTERKEY PID reads PRESNT, that particular key is already programmed into the PCM. The SPAREKEY (spare key) PID is defaulted to ENABLE. With the SPAREKEY PID displaying ENABLE, the PCM will accept more than 2 keys (up to a maximum of 8) being programmed into the PCM. It can be toggled to DISABLE if the customer does not want any more than 2 keys programmed into the PCM using the Key Programming Using Two Programmed Keys  procedure. Refer to Key Programming Switch State Control  in this article to ENABLE/DISABLE the SPAREKEY PID.