A plastic surge tank, is connected to the cooling system with three hoses. As the car is driven, the coolant is heated and expands. Fluid displaced by this expansion flows to the tank.
The tank is mounted at a point higher than all other coolant passages, thereby providing air bleed for the system. The coolant level in the radiator surge tank should be maintained at or slightly above the weld line.
A coolant level float switch is located within the surge tank. When the coolant in the system falls below the recommended level (approximately 1.5L), a message of low coolant level will be displayed on the IPC/DIC.
The coolant level switch senses the presence or absence of coolant in the pressurized coolant overflow bottle using a float. When the float is suspended in coolant, the switch will be closed. When the float is not suspended in coolant, the switch will open, indicating low coolant level. The PCM monitors the state of the coolant level switch through CKT 1478. When the coolant level switch is closed, CKT 1478 is at 0 volts, indicating adequate coolant level. When the switch opens to indicate low coolant, CKT 1478 is open (12 volts).
There are two messages associated with the Optical Engine Oil Level sensor. The Low Oil Level message is displayed when the system detects engine oil level that is to low. The Oil Level Problem message indicates a circuit fault has been detected in the Optical Oil Level sensor system. The Optical Oil Level sensor is located on the engine oil pan.
The CHANGE ENGINE OIL message is triggered by the Oil Life Left index. When the Oil Life Left index drops to 0%, the Change Engine Oil message will appear to the driver. The Oil Life Left index is calculated by the PCM and stored in the EEPROM (see EEPROM ) of the PCM. The PCM uses coolant temperature, engine speed, and vehicle speed to calculate the index. After an oil change, the index may be reset by displaying the Oil Life Left index and then pressing and holding the Reset button on the IPC for approximately 5 seconds or by using the scan tool. When the value is reset, 100% Oil Life Left will be displayed.
The PCM calculates a Transaxle Fluid Life Index using transaxle temperature and engine state, running or OFF. The Transaxle Fluid Life Index represents the remaining useful transaxle fluid life as a percentage of total life. When transaxle fluid life reaches 0%, the CHANGE TRANS FLUID message will appear. The Transaxle Fluid Life Index can be reset the same as the engine Oil Life Left index.
