OIL TEMPERATURE INDICATOR
DESCRIPTION
An oil temperature indicator is found only in the instrument cluster of SRT8 vehicles. The oil temperature indicator is an additional function of the Electronic Vehicle Information Center (EVIC) and is selected using the STEP button in the upper instrument panel switch pod while in the trip computer mode. This indication appears within the reconfigurable dot matrix Organic Light Emitting Diode (OLED) display unit.
The oil temperature indicator consists of an International Control and Display Symbol icon for Engine Oil Temperature, a gauge bar, and an alpha/numeric display of the current oil temperature in either °C (Celsius) or °F (Fahrenheit), as selected with the U.S./METRIC feature of the EVIC. The indicator displays values from 60 to 150 °C, or from 140 to 300 °F. The oil temperature indicator appears in place of the compass/trip computer information in the dot matrix display.
The dot matrix OLED is soldered onto the cluster electronic circuit board, and is visible through a window with a smoked clear lens located on the lower edge of the tachometer gauge dial face of the cluster overlay. The dark lens over the OLED prevents the indicator from being clearly visible when it is not illuminated. The oil temperature indicator appears in the same blue-green color and at the same lighting level as the compass/trip computer information when it is illuminated by the instrument cluster electronic circuit board.
The oil temperature indicator is serviced as a unit with the OLED in the instrument cluster.
OPERATION
The oil temperature indicator gives an indication to the vehicle operator of the engine oil temperature. This indicator is controlled by the instrument cluster logic circuit based upon cluster programming, an input from the upper instrument panel switch pod, and electronic messages received by the cluster from the Powertrain Control Module (PCM) over the Controller Area Network (CAN) data bus.
The oil temperature indicator function of the reconfigurable dot matrix Organic Light Emitting Diode (OLED) display unit is completely controlled by the instrument cluster logic circuit, and that logic will only allow this indicator to operate when the instrument cluster receives a battery current input on the fused ignition switch output (run-start) circuit. Therefore, the OLED oil temperature indication will always be OFF when the ignition switch is in any position except ON or START. The instrument cluster will turn ON the oil temperature indicator for the following reasons:
- Oil Temperature Indicator Request - Each time the cluster is in the compass/trip computer mode and receives a request from the STEP button in the upper instrument panel switch pod to step to the appropriate sequence of the trip computer display, the oil temperature indicator will be displayed showing the current engine oil temperature value. The cluster receives electronic engine oil temperature messages from the PCM indicating the temperature. The indicator remains illuminated until the cluster receives another request from the STEP button, until the cluster arbitrator logic determines that another display request has priority, or until the ignition switch is turned to the OFF position, whichever occurs first.
The PCM continually monitors the engine oil temperature sensor to determine the engine oil temperature. The PCM then sends the proper electronic messages to the ElectroMechanical Instrument Cluster (EMIC).
For proper diagnosis of the engine oil temperature sensor, the PCM, the EMIC, the CAN data bus or the electronic communication related to oil temperature indicator operation a diagnostic scan tool is required. Refer to the appropriate diagnostic information.