P0940Hydraulic Oil Temperature Sensor Circuit High
- Generic OBD-II code · Powertrain
- Turns on the check-engine light
- Matters for the ITP
- How the car detects it
- The hydraulic oil temperature sensor signal sits above its valid window. With an NTC thermistor this matches an extremely cold reading, typically from an open circuit, an unplugged connector, a broken ground or a short to a voltage source. Ferrari uses P0940 on its DCT for the radiator outlet and gearbox inlet oil temperature sensor, described as an electrical fault with signal too high, read in the NCR gearbox ECU. CARB requires out-of-range checks on transmission sensors. P0939 is the low counterpart, P0937 the general circuit fault, P0938 plausibility and P0941 intermittent. With a substitute value the gearbox works on, but clutch and shift pressures are no longer matched to the real oil temperature.
- What you may notice
- Gearbox warning light on
- Shifts or clutch engagements feel rough once warm
- Likely causes
- LikelyOpen signal or ground wire, or connector unplugged
- PossibleTemperature sensor open internally
- RareSignal wire shorted to a voltage source
- Inspection (ITP)
- Matters for the ITP. While the check-engine light is on, the car fails the emissions check.
- Repair
- Medium · Usually a job for a workshop.Typical cost: €80 – €500
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.