P0295

Cylinder 12 Injector Circuit High

P0295 is a generic OBD-II powertrain diagnostic trouble code: Cylinder 12 Injector Circuit High. It is logged by the engine control unit when the fuel/inj monitor detects that a specific fault threshold has been exceeded — typically resulting in the malfunction-indicator lamp (MIL / check-engine light) being illuminated.

Code
P0295
Group
Powertrain
System
Fuel/Inj
Severity
Warning (MIL on, possible limp mode)
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What P0295 means

P0295 is set when the powertrain control module (PCM) detects that the fuel injector control circuit for cylinder 12 is operating at a voltage or current level above the expected high threshold. The PCM continuously monitors the driver circuit for each injector; when the measured signal falls outside the manufacturer-specified window on cylinder 12's circuit, this code is stored and the malfunction indicator lamp (MIL) is illuminated.

Because cylinder 12 is only present in V12 and W12 engines — found in vehicles such as BMW 7-Series (N73/N74), Audi A8 W12, Bentley Continental, and Lamborghini platforms — P0295 is relatively rare compared to lower-cylinder codes. The fault may indicate an injector with a shorted solenoid coil drawing excessive current, damaged wiring raising circuit voltage, or a failing PCM driver transistor. The condition directly disrupts fuel delivery to that cylinder, causing an effective misfire on cylinder 12.

Left unaddressed, the fault allows uncontrolled or absent fuelling of cylinder 12, risking raw fuel entering the exhaust, catalytic converter damage, and accelerated engine wear. Prompt diagnosis is essential, beginning with circuit inspection before condemning the injector or PCM.

Common causes

Most-frequently reported root causes when P0295 is logged.

  • 1
    Shorted injector solenoid coil on cylinder 12 causing excessive current draw.
  • 2
    Damaged, chafed, or corroded wiring and connector pins in the cylinder 12 injector harness.
  • 3
    Loose or backed-out connector pin at the injector or PCM harness connector.
  • 4
    Failing PCM injector driver transistor for cylinder 12 outputting abnormally high voltage.
  • 5
    Voltage spike from a faulty alternator voltage regulator or poor chassis ground affecting the injector circuit.
  • 6
    PCM software corruption causing misinterpretation of normal injector feedback signals.

Symptoms drivers notice

Malfunction indicator lamp (MIL) illuminated, sometimes flashing during active misfire.
Rough idle or engine vibration consistent with a cylinder-12 misfire.
Noticeable power loss or hesitation during acceleration.
Reduced fuel economy due to disrupted fuelling on cylinder 12.
Possible raw fuel odour from the exhaust when the cylinder fires without proper control.

How to diagnose P0295

A typical diagnostic flow when this code is present.

  1. 1
    Connect an OBD-II scan tool, confirm P0295, and note any companion misfire codes (e.g. P027C).
  2. 2
    Visually inspect the cylinder 12 injector wiring harness for chafing, burn marks, melted insulation, or corroded connector pins; repair as found.
  3. 3
    Measure injector coil resistance with a multimeter — typical specification is 10–20 Ω; values outside this range indicate internal injector failure.
  4. 4
    With the ignition on (engine off), measure voltage at the injector connector; a reading significantly above 12–14 V points to a PCM driver fault.
  5. 5
    Swap the cylinder 12 injector with a known-good injector from another cylinder and re-scan to determine if the fault follows the part or stays on the circuit.
  6. 6
    Check and clean all relevant ground points for the engine harness before suspecting the PCM.
  7. 7
    If wiring, connector, and injector test normal, update PCM software; replace the PCM only if fault persists after reprogramming.

Related powertrain codes

Frequently asked questions

Which vehicles actually have a cylinder 12?

Only V12 and W12 engines have a cylinder 12. Common examples include BMW 7-Series (N73/N74 V12), Audi A8 and Bentley Continental (4.0 W12), Lamborghini Aventador (V12), and Ferrari 812 (V12). P0295 is essentially irrelevant on any engine with fewer than 12 cylinders.

Will P0295 cause a misfire code to appear alongside it?

Yes. If the injector circuit fault prevents proper fuelling, the PCM will typically also log a cylinder 12 misfire code such as P030C. Diagnosing both codes together helps isolate whether the root cause is electrical (circuit high) or mechanical (injector stuck closed).

Can I drive the vehicle with P0295 active?

Short distances are possible, but it is not advisable. Continuous misfiring on cylinder 12 sends unburned fuel into the exhaust, which can overheat and destroy the catalytic converter. On a high-performance V12 or W12, abnormal combustion events can also damage pistons and valves.

Is this always caused by a bad injector?

Not necessarily. The code reflects a circuit-level condition, so wiring damage and PCM driver faults are equally common culprits. Always test the circuit resistance and voltage before replacing the injector, as a new injector will not fix a wiring or PCM fault.

Disabling P0295 in software

RaceTune can permanently disable P0295 — 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.

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