P23CCFuel Rail Heater Control Circuit High
- Generic OBD-II code · Powertrain
- Turns on the check-engine light
- Matters for the ITP
- How the car detects it
- With P23CC the fuel rail heater control circuit sits at supply voltage when it should not, most often because the line has shorted to a battery feed or the switching element is stuck conducting. The concern is uncontrolled heating: if the element keeps running, the fuel in the rail can get hotter than intended once the engine is warm. No manufacturer documents P23CC publicly. For reference, Bosch gives a target fuel temperature window of about 70 to 125 °C for its heated Flexstart rail, depending on system pressure, and says its heating unit diagnoses the switching FETs. CARB treats heated fuel preparation as a monitored output. Hot-start problems or vapour issues are possible alongside the warning lamp. Ground shorts are P23CB, an open circuit P23CA.
- What you may notice
- Rail heater stays on after start
- Hard restart when the engine is hot
- Engine warning lamp, depending on manufacturer
- Likely causes
- LikelyHeater control wire shorted to a battery feed
- PossibleSwitching transistor in the heater unit stuck conducting
- PossibleInternal fault in the fuel heater control module
- RareDamaged terminals letting adjacent pins touch
- 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 – €700
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.