Possible Causes

WARNING: This page is about a different car, the 2005 Mazda Tribute. However, it is still accessible from the selected car via links, so may be relevant.

less than two keys programmed to the system
PATS transceiver
unprogrammed PATS key
PCM

PINPOINT TEST 6: ANTI-THEFT NUMBER OF PROGRAMMED KEYS IS BELOW MINIMUM

PINPOINT TEST 6		ANTI-THEFT NUMBER OF PROGRAMMED KEYS IS BELOW MINIMUM
STEP	INSPECTION		ACTION
1	RETRIEVE THE DTCS Key OFF. Key ON, Engine OFF (KOEO). Is DTC B1213 retrieved?	Yes	Go to next step.
1		No	If other than PATS PCM DTCs are retrieved, See COMMUNICATIONS NETWORK . If no PATS DTCs are retrieved, the system is OK.
2	CHECK THE NUMBER OF KEYS ENCODED MONITOR THE PCM PID NUMKEYS Monitor the PCM PID NUMKEYS. Does the PCM PID NUMKEYS display less than two encoded ignition keys programmed?	Yes	Go to next step.
2		No	The system is OK.
3	PROGRAM ENCODED IGNITION KEYS NOTE: Two programmed, encoded ignition keys must be available to start the vehicle. NOTE: Check to make sure the customer and new encoded ignition keys are approved encoded PATS ignition keys. Unapproved PATS keys do not always operate correctly over different temperature ranges (encoded ignition keys from Huf, Rotunda, or Strattec are approved encoded ignition keys). Cut a new encoded PATS ignition lock cylinder key. Program the new encoded ignition key. See KEY PROGRAMMING USING DIAGNOSTIC EQUIPMENT Does the theft LED illuminate for 3 seconds and then go out?	Yes	CLEAR the DTCs. CYCLE the ignition OFF then back to RUN to verify all codes have been cleared. REPEAT the self-test. TEST the system for normal operation.
3		No	Go to next step.
4	CHECK FOR A REPAIR MODULE MONITOR THE PCM PID SERV_MOD Monitor the PCM PID SERV_MOD. Does the PCM PID SERV_MOD indicate YES?	Yes	PROGRAM the encoded ignition keys. See KEY PROGRAMMING USING DIAGNOSTIC EQUIPMENT .
4		No	If the LED is illuminated continuously, REPEAT Step 3 using a new encoded ignition key. If the LED is flashing, RETRIEVE the PCM DTC stored for the new PATS fault.