DTC Parameters
DTC P1626 will set if PCM lest Class II communications with the BCM or the fuel decision timer timed out after 5 seconds of engine run time. Timer will time out if no DTC was received within 5 seconds of engine run time.
DTC diagnostic runs continuously for BCM information, but only once for fuel decision timer. If the PCM receives a password (correct or incorrect) it will not run a diagnostic for the fuel decision timer until the ignition is cycled.