Change Engine Oil Soon

The change oil soon telltale is turned On by the cluster when it receives a command from the PCM (4 cylinder) or the BCM (V6). The ECM sends a message to the BCM over the CAN serial data link. The change oil soon telltale is commanded. On based on a calculated value of time and mileage. This indicates to the operator of the vehicle that the oil should be changed as soon as possible.