DTC B2722, Pass-Key(R) Detection Circuit (Short To Ground): Notes
PASS-Key(R) II detection circuit is completed when PASS-Key(R) II (with embedded resistor pellet) is inserted in ignition lock cylinder. When contacts in lock cylinder mate with contacts of resistor pellet, BCM compares resistance value of key pellet to valid resistance programmed into BCM.
If BCM determines that resistance value of key pellet is okay, BCM will use the class 2 serial data line to send a password to Powertrain Control Module (PCM). PCM will then energize theft deterrent relay and allow fuel delivery to engine.
DTC B2722 will set when voltage level of PASS-Key(R) input circuit is low (indicating invalid resistance detected or a short to ground) during crank cycle or for one second anytime after engine has been started.
When DTC B2722 is set, BCM will send a message to instrument panel to turn on SECURITY warning indicator. If DTC is set during crank cycle, BCM will not send a message to PCM to enable theft deterrent relay and allow fuel delivery to engine (vehicle will exhibit a "no crank" condition). If DTC occurs laters in ignition cycle, BCM will enter fail-enable mode. During subsequent engine starts, BCM will send a message to PCM to enable theft deterrent relay and to allow fuel delivery to engine.
If conditions for malfunction no longer exist, history DTC will clear after 100 consecutive ignition cycles. DTC B2722 will also clear when conditions no longer exist or scan tool is used to clear codes.