DTC P2681-11: Engine Coolant Bypass Valve Circuit Short to Ground; DTC P2681-15: Engine Coolant Bypass Valve Circuit Short to Battery or Open [11/2021 - 03/2022]: Procedure
WARNING: This page is about a different car, the 2025 Lexus NX 350h, 2024 Lexus NX 350h, 2023 Lexus NX 350h, and 2022 Lexus NX 350h. However, it is still accessible from the selected car via links, so may be relevant.
- CHECK TERMINAL VOLTAGE (POWER SOURCE OF FLOW SHUTTING VALVE)
- Disconnect the flow shutting valve (water by-pass hose assembly) connector.
- Turn the ignition switch to ON.
- Measure the voltage according to the value(s) in the table below.
Standard Voltage
Tester Connection Condition Specified Condition B33-2 (+FSV) - Body ground Ignition switch ON 11 to 14 V Result
Proceed to OK NG
Result:
NG
REPAIR OR REPLACE HARNESS OR CONNECTOR (EFI-MAIN NO. 1 RELAY - FLOW SHUTTING VALVE)
Result:
OK
See step 2
- INSPECT FLOW SHUTTING VALVE (WATER BY-PASS HOSE ASSEMBLY)
Refer to INSPECTION [11/2021 - ]
Result
Proceed to OK NG Result:
NG
REPLACE FLOW SHUTTING VALVE (WATER BY-PASS HOSE ASSEMBLY). Refer to REMOVAL [11/2021 - ]
Result:
OK
See step 3
- CHECK HARNESS AND CONNECTOR (FLOW SHUTTING VALVE - ECM)
- Disconnect the flow shutting valve (water by-pass hose assembly) connector.
- Disconnect the ECM connector.
- Measure the resistance according to the value(s) in the table below.
Standard Resistance
Tester Connection Condition Specified Condition B33-1 (-FSV) - B48-42 (WSV1) Always Below 1 Ω B33-1 (-FSV) or B48-42 (WSV1) - Body ground and other terminals Always 10 kΩ or higher Result
Proceed to OK NG
Result:
OK
REPLACE ECM. Refer to REMOVAL [11/2021 - ]
Result:
NG
REPAIR OR REPLACE HARNESS OR CONNECTOR