The P2681 code indicates that the engine control module has detected an open circuit in the engine coolant bypass valve control circuit. This means the electrical path to the solenoid is broken, preventing the valve from operating correctly to regulate coolant flow.
The internal coil of the coolant bypass valve has failed or burnt out, creating an open circuit.
The wires connecting the PCM to the bypass valve are frayed, broken, or severed due to heat or abrasion.
Corrosion or contamination in the solenoid connector terminals has broken the electrical connection.
The wiring harness connector is not fully seated or locked into the bypass valve.
The internal driver circuit within the engine control module has failed, though this is rare.
No. P2681 is an electrical circuit code. While a bad thermostat affects coolant flow, it will not trigger an open circuit code for the bypass valve.
Usually not. In the vast majority of cases, the fault lies with the solenoid itself or the wiring. The PCM should only be considered if the valve and wiring have been thoroughly verified as functional.
Yes, the vehicle will generally remain drivable, but it may experience poor heating or inefficient engine warm-up cycles.