U1300 Class 2 Short to Ground - DLC

DTC U1300: Class 2 Short To Ground:

CIRCUIT DESCRIPTION
While the ignition switch is in RUN, modules communicating on the Class 2 Data Bus send a "State of Health" (SOH) message every 5 seconds to ensure that the system is operating properly.

CONDITIONS FOR SETTING THE DTC
^ These Diagnostic Trouble Codes (DTCs) will set only if DTC B1982 or B1983 is not current.
^ The module detects that the Class 2 bus is shorted to ground for at least 3 seconds.

CONDITIONS FOR CLEARING THE DTC
The module detects that the Class 2 bus is not shorted to ground.

DIAGNOSTIC AIDS
^ This DTC is never received as current because the Class 2 bus does not function during this condition.
^ Check CKT 1807 (PPL) for intermittent shorts to ground.