Diesel Data: Automotive Repair

Coolant Level Information

The engine coolant level switch sends the engine coolant level information to the powertrain control module (PCM). If the switch returns a signal that indicates a low coolant condition, the PCM transmits a low engine coolant signal to the instrument cluster on the universal asynchronous receiving/transmitting (UART) B serial data line. The driver information center (DIC) then displays the LOW ENGINE COOLANT warning.