P23CAFuel Rail Heater Control Circuit/Open
- Generic OBD-II code · Powertrain
- Turns on the check-engine light
- Matters for the ITP
- How the car detects it
- Some flex-fuel engines heat the fuel directly in the injector rail: a heating element in the rail brings ethanol up to temperature just before a cold start. P23CA flags the control circuit of that rail heater as open or otherwise faulty, so no heating current flows. No manufacturer documents P23CA publicly. Bosch's Flexstart rail uses such an element, rated at 260 W from a 12 V supply and able to warm E100 by up to 30 °C per second; the engine module commands it through the heating control unit based on ethanol share and ambient temperature. CARB lists heated fuel preparation among output components to be monitored. Cold starts on ethanol may fail; heaters mounted per cylinder have their own codes from P23D1 onwards.
- What you may notice
- No start or long cranking on ethanol below about 13 °C
- Misfiring or stumbling in the first seconds after a cold start
- Engine warning lamp, depending on manufacturer
- Likely causes
- LikelyBurnt-out heating element in the fuel rail
- PossibleBroken wire or unplugged connector at the rail heater
- PossibleCorroded high-current terminals at the heater
- RareFailed output stage in the fuel heater control module
- 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.