DTC P154A: General Description
The local interconnect network (LIN) line connects the 12 volt battery sensor and the powertrain control module (PCM). The LIN uses a master/slave protocol to send and receive data to the different components on the line. The PCM is the master unit, which controls the engine electrical system, and the 12 volt battery sensor is the slave that receives data and provides feedback to the PCM. The 12 volt battery sensor is connected between the 12 volt battery and ground. The 12 volt battery sensor measures the 12 volt battery's current, voltage, and temperature. When the PCM requests this information to operate the engine electrical system efficiently, the 12 volt battery sensor runs a diagnostic program and sends the results to the PCM via the LIN. If the diagnostic results are outside the normal range, the PCM detects a malfunction and stores a DTC.