OBD Fuel Heater Control Module Power Control Circuit/Open
What it means
P23C7 stands for Fuel Heater Control Module Power Control Circuit/Open. P23C7 is a P code, so the fault sits in the engine, transmission and emissions systems. For P23C7, the second digit places it in ignition and misfire. For P23C7, work through the cause list below, cheapest checks first.
Where it lives
For P23C7, the module sits on the circuit this code reports. The description of P23C7 reports the module as open.
What to check first
For P23C7, pull the connector and inspect the terminals for spread, corrosion or backed-out pins before testing anything else.
Check these first
- P23C7: Failing ignition coil, spark plug, or spark plug wire
- P23C7: Faulty crankshaft or camshaft position sensor
- P23C7: Wiring or connector damage in the ignition circuit
- P23C7: Low compression or engine mechanical wear
- P23C7: Incorrect ignition timing or a stretched timing chain
What to do next
P23C7 belongs to the ignition and misfire system. These are the general steps for P23C7, and the exact cause on your vehicle can differ.
- P23C7: Read misfire counts and freeze frame data with an OBD-II scanner
- P23C7: Test spark output and inspect spark plugs and coils
- P23C7: Check crankshaft and camshaft position sensor signals while cranking
- P23C7: Swap suspect ignition parts between cylinders to see if the fault moves
- P23C7: Compression test if the issue persists on the same cylinder
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Updated
Generic SAE J2012 definition. Last updated 2026-08-30.