Engine Coolant Flow Control Valve
The motorised valve that replaced the wax thermostat in modern thermal management. Commanded by the module, it routes coolant — through the radiator, the heater, the block, or nowhere at all — so a cold engine can warm in minutes with its coolant held still, and a hybrid can harvest engine heat for the cabin on demand. A position sensor reports where the valve actually is, and the module trusts nothing it cannot verify.
Its failure directions are not equal. Failed toward open, the engine runs cold — slow warm-up, tepid heater, higher consumption, the classic stuck-open-thermostat picture with an electrical cause. Failed toward closed, coolant cannot reach the radiator, and that is an overheat measured in minutes of load. The temperature gauge outranks every code this valve can store.
It sticks the way rotary valves in coolant stick — scale, debris, a seal swelling — and its motor current rising over time is the early warning the module watches for.
Also known as: coolant control valve, rotary coolant valve, thermal management valve, coolant valve
Referenced by 82 codes
Codes involving this component (82)
- P2B61 Engine Coolant Flow Control Valve Stuck Closed Stop driving High
- P2B58 Engine Coolant Flow Control Valve Motor Current High Moderate
- P2B59 Engine Coolant Flow Control Valve Control Circuit/Open Moderate
- P2B5A Engine Coolant Flow Control Valve Control Circuit Low Moderate
- P2B5B Engine Coolant Flow Control Valve Control Circuit High Moderate
- P2B5C Engine Coolant Flow Control Valve Supply Circuit Low Moderate
- P2B5D Engine Coolant Flow Control Valve Position Sensor Circuit Moderate
- P2B5E Engine Coolant Flow Control Valve Position Sensor Circuit Low Moderate
- P2B5F Engine Coolant Flow Control Valve Position Sensor Circuit High Moderate
- P2B60 Engine Coolant Flow Control Valve Position Sensor Circuit Range/Performance Moderate
- U0615 Lost Communication With Engine Coolant Bypass Valve A Moderate
- P261A Coolant Pump B Control Circuit/Open
- P261B Coolant Pump B Control Circuit Performance/Stuck Off
- P261C Coolant Pump B Control Circuit Low
- P261D Coolant Pump B Control Circuit High
- P261E Coolant Pump B Control Circuit Stuck On
- P261F Coolant Pump A Control Circuit Stuck On
- P26AC Engine Coolant Bypass Valve B Control Circuit/Open
- P26AD Engine Coolant Bypass Valve B Control Circuit Low
- P26AE Engine Coolant Bypass Valve B Control Circuit High
- P26AF Engine Coolant Bypass Valve B Stuck/Open
- P26B0 Engine Coolant Bypass Valve B Range/Performance
- P26B1 Engine Coolant Bypass Valve A Stuck Closed
- P26B2 Engine Coolant Bypass Valve B Stuck Closed
- P26B7 Engine Coolant Bypass Valve C Control Circuit/Open
Other components in Cooling
- Electric Coolant Pump 149
- Engine Coolant Temperature Sensor 105
- 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
- Coolant Expansion Tank 8
- Fuel Fired Heater 5
- Coolant Degassing Valve 3
- Oil Cooler 1
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