PASS-KEY II Malfunctions

PASS-KEY II system uses a resistor pellet with 15 different potential values in vehicle ignition key. When key is inserted into ignition key cylinder, pellet value is read and compared to 3 vehicle specific key values stored in memory. Result of this comparison is used to determine whether or not to allow vehicle starting and to also display system status messages. Displayed messages indicate whether a valid or invalid key pellet value has bee detected or if there is a problem with the key pellet read circuitry. If a valid code is detected, IPC will send a class 2 serial data bus password message, along with a request to enable fuel, to PCM. PCM must recognize password by checking against 3 values stored in EEPROM before fuel is enabled. IPC will not energize starter enable relay until PCM responds with vehicle status report acknowledgment to password message. Any deviation in the sequence will result in a DTC.