What it means
The fuel rail heater control circuit is reporting a high condition. The code does not establish that this is a sensor heater or affects lambda control.
At a glance
- Usually lights the check-engine light
- Affects emissions; the car can fail an emissions test
How it works
The fuel rail heater control circuit carries the command used to operate the heater associated with the fuel rail. The control module sets P23CC when it detects a high electrical condition on that control line, which may happen if the wire contacts a power supply.
Common causes
Most likely first.
- Control line shorted to supply
- Connector pins corroded - high contact resistance
- Supply wire pinched against B+ source
Symptoms
- Check engine light
- Fuel or powertrain warning light, if equipped
- Hard starting or rough running in cold weather
- Reduced engine performance in cold conditions
How to diagnose it
- Record freeze-frame data and check whether the fault occurred during cold operation, when the fuel rail heater may be commanded.
- Inspect the fuel rail heater control wire for crushed insulation or contact with a powered wire or terminal.
- Check the heater and module connectors for corrosion, moisture, loose pins, or terminals pushed back into the connector.
- Compare the control circuit’s live reading with the heater command and see whether it stays high as the command changes.
- Test for an unintended connection between the control wire and a supply circuit, following the manufacturer's wiring information.
Common fixes
- Repair the control wire where it is pinched against a power source.
- Clean or repair corroded, loose, or pushed-back connector terminals.
- Replace damaged wiring or a connector that allows the control line to contact supply voltage.
- Replace the heater control module only if the wiring and connections test correctly.
Can I keep driving?
The vehicle may run normally in mild conditions, but a fuel rail heater fault can make cold starts difficult and reduce performance in cold weather. Avoid depending on it in freezing conditions until the high condition is corrected.
A code shows where the control module detected a fault, not always which part failed. Check the causes in order and confirm with a test before replacing parts. Have several codes? Check them together
This is a generic code: it means the same on every make. The car’s maker may add more detail in its own service information.