Low Oil Level Indicator: Operation

WARNING: This page is about a different car, the 2006 Dodge Sprinter. However, it is still accessible from the selected car via links, so may be relevant.

The low oil level indicator gives an indication to the vehicle operator when the engine oil level is low. This indicator is controlled by a transistor on the instrument cluster electronic circuit board based upon cluster programming and electronic messages received by the cluster from the Engine Control Module (ECM) over the Controller Area Network (CAN) data bus. The low oil level indicator Light Emitting Diode (LED) is completely controlled by the instrument cluster logic circuit, and that logic will only allow this indicator to operate when the instrument cluster detects that the ignition switch is in the On position. Therefore, the LED will always be off when the ignition switch is in any position except On. The LED only illuminates when it is provided a path to ground by the instrument cluster transistor. The instrument cluster will turn on the low oil level indicator for the following reasons:

Bulb Test - Each time the ignition switch is turned to the On position the low oil level indicator is illuminated for about two seconds as a bulb test.
Engine Oil Level Low Message - Once the engine has been started, each time the cluster receives a message from the ECM indicating that the engine oil level is at or near the "Minimum" mark on the dipstick, the low oil level indicator is illuminated. The indicator remains illuminated briefly at first, but will remain illuminated for longer periods as subsequent messages indicate that the oil level has dropped further. Eventually, the indicator will remain illuminated solid until the engine oil level is corrected, or until the ignition switch is turned to the Off position, whichever occurs first.

The instrument cluster also supplements the oil level indicator by displaying an engine oil icon along with alpha-numeric messages in the multi-function indicator Liquid Crystal Display (LCD) advising the vehicle operator how much oil is required to correct the engine oil level, and when the "Maximum" engine oil level has been exceeded. See the owner's manual in the vehicle glove box for more information on this feature.

The ECM continually monitors the engine oil level and temperature sensor to determine the engine oil level. The ECM then sends the proper engine oil level messages to the instrument cluster. If the instrument cluster turns on the indicator after the bulb test, even after the engine oil level is sufficient, it may indicate that the engine or the engine oiling system requires service. For proper diagnosis of the engine oil level and temperature sensor, the ECM, the CAN data bus, or the electronic message inputs to the instrument cluster that control the low oil level indicator, a diagnostic scan tool is required. Refer to BODY DIAGNOSTIC PROCEDURES .