P1123 Coolant Flow Control Valve Position Sensor Circuit High
What does P1123 mean on a Toyota?
P1123 — Coolant Flow Control Valve Position Sensor Circuit High. This Toyota-enhanced code applies to Prius with coolant flow control valve.
Common causes of P1123
- Open valve position circuit
- Failed position sensor
- Stuck coolant flow valve
- Corroded connector
- ECM input fault
How to fix P1123
- Command the valve and watch position feedback
- Test position sensor output
- Check for a stuck valve
- Inspect wiring and connector
- Replace the valve assembly per response