Engine Coolant Expansion Tank
| ITEM | DESCRIPTION |
|---|---|
| 1 | Filler cap |
| 2 | Air bleed hose connection |
| 3 | Minimum and maximum level markings |
| 4 | Expansion hose connection |
| 5 | Engine coolant level sensor |
The engine coolant expansion tank is installed in the rear right of the engine compartment.
A filler cap and level sensor are incorporated into the expansion tank. A 'MAX' and 'MIN' cold fill level markings are molded into the exterior of the tank below the filler cap.
The coolant expansion tank provides the following functions:
- The service fill.
- Engine coolant expansion during warm up.
- Air separation during operation.
- System pressurization by the filler cap.
- Coolant level sensing.
The engine coolant expansion tank has an air space of approximately 0.5 liter (1.06 US pints), above the MAX level, to allow for coolant expansion.
The engine coolant level sensor locates in a sealed cavity at the bottom of the coolant expansion tank body. A float with an integral magnet is located inside the coolant expansion tank. The coolant level sensor contains a switch that reacts to the position of the magnetic float. The coolant level sensor is hardwired to the Body Control Module/Gateway Module (BCM/GWM).
The magnetic float is designed to float very close to the bottom of the tank, significantly below the MIN cold fill coolant level. The magnetic float in this position does not indicate float failure, for example sinking or sticking. The float has a travel distance of approximately 15 mm (0.59 in) from the bottom of the tank.