DTC U12B4: General Description
The controller area network (CAN) transmits/receives pulsing signals to/from the control modules simultaneously by using two signal lines (H line and L line). When the information is not sent from the park pawl actuator driver unit via the F-CAN lines and this condition continues for a specified time or when the information sent from the park pawl actuator driver unit is abnormal and this condition continues for a specified cycle, the powertrain control module (PCM) detects a malfunction and stores a DTC.