Coolant Expansion Tank
The reservoir that accommodates coolant expanding as it heats and returns it as it cools, and on most vehicles the place where level is checked and the pressure cap lives. The tank is moulded plastic living through constant heat cycling, so it cracks along its seams with age, and its cap is a wearing part with a spring and a seal — a cap that no longer holds rated pressure lowers the coolant's boiling point and pushes it out of the overflow, which presents as a leak with nothing leaking.
Also known as: expansion tank, coolant reservoir, header tank, overflow bottle, coolant bottle, surge tank
Referenced by 8 codes
Codes involving this component (8)
- P2560 Engine Coolant Level Low Stop driving Critical
- P2556 Engine Coolant Level Sensor/Switch Circuit High
- P2557 Engine Coolant Level Sensor/Switch Circuit Range/Performance High
- P2558 Engine Coolant Level Sensor/Switch Circuit Low High
- P2559 Engine Coolant Level Sensor/Switch Circuit High High
- P2678 Coolant Degassing Valve Control Circuit/Open Moderate
- P2679 Coolant Degassing Valve Control Circuit Low Moderate
- P2680 Coolant Degassing Valve Control Circuit High Moderate
Other components in Cooling
- Electric Coolant Pump 149
- Engine Coolant Temperature Sensor 105
- Engine Coolant Flow Control Valve 82
- Radiator 61
- Active Grille Shutter Module 53
- Engine Coolant Bypass Valve 42
- Thermostat 40
- Cooling Fan 40
- Engine Coolant Level Sensor 15
- Water Pump 12
- Radiator Coolant Temperature Sensor 11
- Fuel Fired Heater 5
- Coolant Degassing Valve 3
- Oil Cooler 1
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