P23CA
Fuel Rail Heater Control Circuit Open
The fuel rail heater - on common-rail diesels for cold-start - has an open control circuit. The rail cannot be heated, slowing cold-start fuel atomisation.
- Check engine light: Yes
- Emissions related: Yes
- Repair difficulty: medium
Common causes
Ordered by how often each turns out to be the cause.
- Open in heater or wiringCommon
- Pin pushed back out of connector bodyLess likely
- Cracked solder joint inside the module or sensorLess likely
Parts involved
- Fuel Rail Heater
P23CA is a generic OBD-II code defined by SAE J2012. Exact wording and diagnostic procedure vary by manufacturer and model. Code definitions are drawn from the public-domain OBDex dataset; the workshop notes are our own.