Oil Pressure Gauge

WARNING: This page is about a different car, the 2017 RAM 2500 HD. However, it is still accessible from the selected car via links, so may be relevant.

The oil pressure gauge gives an indication to the vehicle operator of the engine oil pressure. This gauge is controlled by the Instrument Panel Cluster (IPC) based upon cluster programming and electronic messages received over the Controller Area Network (CAN) data bus. These electronic messages are received from the Powertrain Control Module (PCM) or Engine Control Module (ECM), depending on engine application.

The oil pressure gauge is a stepper motor design unit that receives battery current on the IPC electronic circuit board through the fused ignition switch output (run-start) circuit whenever the ignition switch is in the ON or START positions. The cluster is programmed to move the gauge needle back to the low end of the scale after the ignition switch is turned to the OFF position. The IPC electronic circuitry controls the gauge needle position and provides the following features:

Engine Oil Pressure Message - The IPC circuitry restricts the oil pressure gauge needle operation in order to provide readings that are consistent with customer expectations. Each time the cluster receives an electronic engine oil pressure message from the PCM or ECM indicating the pressure is above about 89 kPa (13 psi) the cluster holds the gauge needle at a point near the middle increment within the normal range on the gauge scale.
Engine Oil Pressure Low Message - Each time the IPC receives three consecutive electronic engine oil pressure messages from the PCM or ECM indicating the pressure is below about 89 kPa (13 psi), the gauge needle is moved to the red graduation at the far left end of the gauge scale, the check gauges indicator is illuminated, and a single chime tone is generated. The gauge needle remains at the left end of the gauge scale and the check gauges indicator remains illuminated until the cluster receives a message from the PCM or ECM indicating that the pressure is above about 89 kPa (13 psi), or until the ignition switch is turned to the OFF position, whichever occurs first. The cluster will only turn ON the check gauges indicator in response to a low pressure message if the engine speed is greater than zero.
Communication Error - If the IPC fails to receive an engine oil pressure message, it will hold the gauge needle at the last indication for about 10 seconds, or until the ignition switch is turned to the OFF position, whichever occurs first. After 10 seconds, the IPC will move the gauge needle to the low end of the gauge scale.

The PCM or ECM continually monitors the engine oil pressure sensor to determine the engine oil pressure. The PCM or ECM then sends the proper messages to the IPC. For further diagnosis of the oil pressure gauge or the instrument cluster circuitry that controls the gauge. Refer to DIAGNOSIS AND TESTING . If the instrument cluster turns ON the check gauges indicator due to a low oil pressure gauge reading, it may indicate that the engine or the engine oiling system requires service.