OBD-II code · Powertrain (generic, extended)
P23C9 Fuel Heater Control Module Power Control Circuit High
Same as P23C7 with the control line shorted to supply. Wiring faults of this kind typically come from chafing, water ingress at connector seals, or pin push-back — a wiggle test on the harness while the code is active often confirms the location.
Is it safe to drive with P23C9?
Usually safe to drive in the short term. Get it diagnosed when convenient, sooner if the car drives differently.
Common causes
- Most likelyControl line shorted to supply
- Less likelyConnector pins corroded - high contact resistance
- Less likelySupply wire pinched against B+ source
Repair at a glance
- Difficulty
- Medium
- DIY friendly
- Often, with basic tools
- Typical labour
- 0.6–2 h
- Emissions test
- Usually unaffected
- Parts involved
- Fuel Heater Control Module
Related codes
- P23C6Engine Coolant Bypass Valve C Control Circuit Driver Current or Temperature Too High
- P23C7Fuel Heater Control Module Power Control Circuit Open
- P23C8Fuel Heater Control Module Power Control Circuit Low
- P23CAFuel Rail Heater Control Circuit Open
- P23CBFuel Rail Heater Control Circuit Low
- P23CCFuel Rail Heater Control Circuit High
Code data: OBDex open dataset (CC0). Labour times are typical ranges, not a quote.