Dakota 2WD V6-3.9L VIN X (1997)
Oil Pressure Gauge: Description and Operation
SYSTEM OPERATION
The oil pressure gauge gives an indication of the engine oil pressure. The instrument cluster circuitry controls the gauge pointer position. The
instrument cluster circuitry calculates the proper gauge pointer position based upon an engine oil pressure message received from the Powertrain
Control Module (PCM) on the Chrysler Collision Detection (CCD) data bus.
The PCM uses an input from the engine oil pressure sensor and internal programming to decide what engine oil pressure message is required. The
PCM then sends the proper message to the instrument cluster on the CCD data bus. If the PCM message indicates that oil pressure is too low, the
instrument cluster circuitry moves the gauge needle to the 0 PSI graduation on the gauge face, turns on the Check Gauges lamp, and sends a chime
tone request to the Central Timer Module (CTM). If the PCM message indicates that oil pressure is too high, the instrument cluster circuitry
moves the gauge needle to 110 PSI graduation on the gauge face.
The engine oil pressure sensor is installed in a threaded hole that penetrates an oil passage of the engine. The engine oil pressure sensor contains a
flexible diaphragm and a variable resistor coil. The diaphragm moves in response to changes in the engine oil pressure, which changes the internal
electrical resistance of the sensor.
CIRCUIT OPERATION
The instrument cluster micro-processor calculates engine oil pressure gauge needle position based on the oil pressure data received over the CCD
bus. The Powertrain Control Module (PCM) transmits the data over the CCD bus.
