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Information only. This page provides general educational information about fault code P1023. We do not assess the urgency or safety implications of any specific fault. That requires in-person diagnosis by a qualified mechanic. Full terms.

Recommended next steps

Whether a fault is urgent, drivable, or routine depends entirely on the cause on a specific vehicle, and that can only be determined by a qualified mechanic with diagnostic equipment. If a warning light is illuminated, the most reliable next step is professional diagnosis.

What does P1023 mean?

P1023 is a Powertrain (engine, transmission, fuel system) fault code. It indicates: CNG Fuel Injector 3 Circuit Malfunction.

Manufacturer-specific notes

Some manufacturers publish additional definitions or variations for this code. Always cross-check with your vehicle's own service documentation.

Chevrolet CNG Fuel Injector 3 Circuit Malfunction
Ford Cylinder Head Temperature Sensor 2 Circuit High
GMC CNG Fuel Injector 3 Circuit Malfunction
Jaguar Cylinder Head Temperature Sensor 2 Circuit High
Land Rover Cylinder Head Temperature Sensor 2 Circuit High
Mazda Cylinder Head Temperature Sensor 2 Circuit High
Vauxhall Cylinder Head Temperature Sensor 2 Circuit High
Volvo Cylinder Head Temperature Sensor 2 Circuit High

About Coil Pack codes

Coil pack codes appear on petrol engines and indicate a fault in the ignition coil that fires one or more spark plugs. A failing coil typically causes a misfire on the affected cylinder, often with rough running, a flashing engine warning light, and a noticeable drop in power.

P1023 is one of 150 codes in this category. Browse all Coil Pack codes →

What we know about P1023 specifically

We record the SAE J2012 standardised definition and the system this code belongs to, but we have not yet published detailed driver-reported symptoms, common causes, or step-by-step diagnostic guidance for P1023.

Rather than invent that information by generating generic content from a template, we leave it out. For specific guidance, the most reliable sources are:

  • your vehicle's own service manual or manufacturer-specific technical bulletins
  • a qualified mechanic with a manufacturer-level diagnostic tool
  • a marque specialist familiar with your make and model

Spotted an issue or have something to add? Mechanics, technicians, and drivers who have first-hand experience with P1023 can submit a correction or expansion. We review every submission before publishing, mechanic submissions are prioritised.

Information only, not professional advice

The information on this page is provided for general guidance and educational purposes only. It is not a substitute for diagnosis or repair advice from a qualified mechanic. Always verify any fault before paying for repairs. carfaultcodes.co.uk accepts no liability for decisions made based on this information. Full terms →

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