P23C2

Cylinder 6 Injector Circuit High

P23C2 is a generic OBD-II powertrain diagnostic trouble code: Cylinder 6 Injector Circuit High. It is logged by the engine control unit when the powertrain monitor detects that a specific fault threshold has been exceeded — typically resulting in the malfunction-indicator lamp (MIL / check-engine light) being illuminated.

Code
P23C2
Group
Powertrain
System
Powertrain
Severity
Warning (MIL on, possible limp mode)
Need P23C2 disabled?
RaceTune permanently disables any OBD-II trouble code on supported ECUs — for motorsport, off-road, and export use.
→

What P23C2 means

P23C2 signals a high-circuit fault on the cylinder 6 fuel injector control circuit. The PCM monitors each injector driver output for voltage and current feedback; when cylinder 6 returns a value above the calibrated high limit, this DTC is stored and the MIL is illuminated. The code belongs to the P23Bx-P23Cx injector circuit high family, where the last digit increments with the cylinder number.

On inline-six and V6 engines, cylinder 6 wiring often runs the furthest from the PCM and passes through multiple connectors, increasing the opportunity for harness damage. A short to voltage anywhere along this longer run will produce P23C2. The PCM may respond by disabling cylinder 6 injection to prevent catalyst damage, resulting in a significant misfire and rough operation.

Standard electrical diagnostic procedure applies: retrieve codes, inspect the harness, measure the injector coil, then trace the control wire back to the PCM. Do not replace the injector or PCM until circuit testing has been completed.

Common causes

Most-frequently reported root causes when P23C2 is logged.

  • 1
    Short to battery voltage in the cylinder 6 injector signal wire.
  • 2
    Wiring harness damage at a known chafe point near the firewall or engine mount.
  • 3
    Internally shorted injector coil on cylinder 6.
  • 4
    Corrosion in the cylinder 6 injector connector bridging control and supply pins.
  • 5
    Water intrusion into a harness connector on the long run to cylinder 6.
  • 6
    PCM injector driver circuit fault for cylinder 6 output.
  • 7
    Harness damage from incorrect routing during a previous repair.

Symptoms drivers notice

MIL on with P23C2 stored in memory.
Cylinder 6 misfire and associated rough running.
Noticeable engine vibration, especially on V6 configurations.
Reduced power and possible limp-mode or reduced-engine-power warning.
Elevated emissions at the tailpipe.

How to diagnose P23C2

A typical diagnostic flow when this code is present.

  1. 1
    Retrieve all DTCs and freeze-frame data using a scan tool.
  2. 2
    Visually inspect the full length of the cylinder 6 injector harness for chafing, cuts, or connector damage.
  3. 3
    Check the cylinder 6 injector connector for corrosion, spread terminals, and moisture.
  4. 4
    Measure injector coil resistance at the connector with the harness unplugged.
  5. 5
    With key on, engine off, verify the control pin voltage is not being pulled high before the PCM commands an injection event.
  6. 6
    Use a wiring diagram to trace the control circuit from the connector to the PCM pin, testing for shorts to voltage at each connector along the route.
  7. 7
    Repair confirmed faults, clear DTCs, and verify the repair over a full drive cycle.

Related powertrain codes

Frequently asked questions

Why is P23C2 specific to cylinder 6 and not just a generic injector fault?

SAE J2012 assigns individual codes to each cylinder injector circuit so technicians can pinpoint the affected cylinder without additional testing.

Could a shared ground fault cause P23C2?

A high-circuit code is caused by excess voltage, not by a missing ground. A poor ground would more typically produce a low-circuit or no-response fault.

Can P23C2 appear without a noticeable misfire?

Yes, especially early in the fault development or if the short is intermittent. The MIL may illuminate before drivability symptoms become obvious.

How long can the catalytic converter survive a P23C2 misfire?

This depends on severity. A consistent misfire feeding raw fuel and oxygen into the catalyst can cause damage within a relatively short driving time. Prompt diagnosis is strongly recommended.

Disabling P23C2 in software

RaceTune can permanently disable P23C2 — and any other OBD-II diagnostic trouble code — on every ECU family we support. The monitor is disabled inside the ECU itself, so the fault stops being logged: the warning light stays off and the engine never enters limp mode for this code. The change is tied to your exact software version.

Permanent
The monitor is disabled in the ECU itself — not just cleared. It cannot return.
Tailored to your file
Each patch is matched to your specific software version — never a one-size-fits-all file.
Reversible
The original file is always preserved. Reflash the stock to return the ECU to factory state.

Software modifications affect emissions compliance and are not road-legal in many jurisdictions. RaceTune service files are intended for motorsport, off-road, and export use.

Got P23C2 in your scan?

Upload your ECU file — we'll identify the exact software version and confirm whether a disable is available for your car.

Upload your file