Durango 2WD V8-5.7L Hybrid (2009)
Oil Pressure Warning Lamp/Indicator: Description and Operation
Low Oil Pressure Indicator - Operation
OPERATION
The low oil pressure indicator gives an indication to the vehicle operator when the engine oil pressure reading reflects a condition requiring immediate
attention. This indicator is controlled by a transistor on the instrument cluster circuit board based upon cluster programming and electronic messages
received by the cluster from the Powertrain Control Module (PCM) over the Controller Area Network (CAN) data bus.
The low oil pressure indicator Light Emitting Diode (LED) is completely controlled by the instrument cluster logic circuit. This logic only allows the
indicator to operate when the instrument cluster receives a battery current input on the fused ignition switch output (run-start) circuit. Therefore, the LED
is always off when the ignition switch is in any position except ON or START. The LED only illuminates when it is provided a path to ground by the
instrument cluster transistor. The instrument cluster turns on the low oil pressure indicator for the following reasons:
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Engine Oil Pressure Low Message - Each time the cluster receives an electronic engine oil pressure message from the PCM indicating the
pressure is about 6.9 kPa (1 psi) or lower, the low oil pressure indicator illuminates. The indicator remains illuminated until the cluster receives a
message from the PCM indicating that the pressure is above about 6.9 kPa (1 psi), or until the ignition switch turns to the OFF position, whichever
occurs first. The cluster only turns the indicator on in response to low engine oil pressure if the engine speed is greater than zero.
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Self Test - Each time the cluster is put through the self test, the low oil pressure indicator turns on, then off again during the bulb check portion of
the test to confirm the functionality of the LED and the cluster control circuitry.
The PCM continually monitors the engine oil pressure sensor to determine the engine oil pressure. The PCM then sends the proper messages to the
instrument cluster, also known as the Cab Compartment Node (CCN). For further diagnosis of the low oil pressure indicator or the instrument cluster
circuitry that controls the LED, See: Instrument Cluster / Carrier/Testing and Inspection.
Use a diagnostic scan tool for proper diagnosis of the engine oil pressure sensor, the PCM, the CCN, the CAN data bus or the electronic communication
related to low oil pressure indicator operation. Refer to the appropriate diagnostic information.
