P0205

Injector Circuit Malfunction - Cylinder 5

P0205 is a generic OBD-II powertrain diagnostic trouble code: Injector Circuit Malfunction - Cylinder 5. 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
P0205
Group
Powertrain
System
Fuel/Inj
Severity
Warning (MIL on, possible limp mode)
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What P0205 means

P0205 means the ECM/PCM detected an abnormal electrical condition — an open circuit, short circuit, or out-of-range resistance — on the fuel injector control circuit for cylinder 5. The code is an electrical fault code, not a combustion result code; it means the control module saw unexpected voltage or current on the injector driver line, not necessarily that cylinder 5 failed to fire. Companion misfire codes such as P0305 may appear simultaneously if the injector circuit fault is severe enough to prevent fuelling.

The injector circuit consists of a high-side power feed (typically switched battery voltage), a low-side driver transistor inside the ECM/PCM, and the injector solenoid coil itself (normally 12–16 Ω on a port injector, lower on GDI). A fault can originate at any point: a broken or chafed wire in the harness, corrosion at the injector connector, an open or shorted solenoid winding, or — least commonly — a failed driver stage inside the PCM. Cylinders 5–8 are found only on V6, V8, V10, and V12 engines, so this code is specific to multi-cylinder layouts.

Because one unfuelled cylinder increases unburnt fuel reaching the catalytic converter, a prolonged or severe P0205 can damage the catalyst. If the MIL is flashing rather than steady, a severe misfire is occurring and the vehicle should not be driven until diagnosed.

Common causes

Most-frequently reported root causes when P0205 is logged.

  • 1
    Open or high-resistance wiring in the cylinder 5 injector harness due to heat degradation, chafing, or rodent damage.
  • 2
    Corroded, spread, or loose terminals at the injector connector plug.
  • 3
    Blown fuse or failed relay supplying the injector high-side power rail.
  • 4
    Injector solenoid coil failure — internal open circuit or short circuit within the injector body.
  • 5
    Damaged valve-cover gasket allowing oil to soak into the wiring loom and connector at the injector.
  • 6
    Poor ECM/PCM ground connection causing reference voltage errors on the injector driver circuit.
  • 7
    Failed ECM/PCM injector driver transistor (rare, typically caused by moisture intrusion or sustained short-circuit damage).

Symptoms drivers notice

MIL illuminated steadily, or flashing if an active misfire on cylinder 5 is also present.
Rough idle with a pronounced single-cylinder stumble, especially noticeable at low RPM or on cold start.
Hesitation and loss of power during acceleration, particularly under light throttle.
Possible companion code P0305 (Cylinder 5 Misfire Detected) stored alongside P0205.
Raw fuel smell from the exhaust or increased HC emissions if the injector is stuck partially open.
Decrease in fuel economy as the ECM attempts to compensate for the affected cylinder.

How to diagnose P0205

A typical diagnostic flow when this code is present.

  1. 1
    Connect a scan tool, retrieve all codes, and note whether P0305 or other misfire codes accompany P0205 — check freeze-frame data for engine load and RPM at fault set.
  2. 2
    Visually inspect the cylinder 5 injector wiring harness and connector for chafed insulation, burnt spots, corrosion, spread terminals, or oil contamination.
  3. 3
    With the injector disconnected, measure solenoid resistance across the injector pins — typical port injector spec is 12–16 Ω; GDI injectors vary by design (consult OEM data); an open or near-zero reading indicates a failed injector.
  4. 4
    Use a noid light or suitable LED tester plugged into the injector connector: crank the engine and confirm the light flashes — if it does not flash, the PCM driver or harness is at fault, not the injector.
  5. 5
    Check for battery voltage at the injector high-side feed with the ignition on; confirm the PCM ground circuit shows less than 0.5 Ω drop.
  6. 6
    Perform an injector swap test (swap cylinder 5 injector with an adjacent cylinder) and re-scan to confirm whether the fault follows the injector or stays on the cylinder 5 circuit.
  7. 7
    If all external circuit tests pass and the fault remains, perform a PCM driver output test with a dealer-level scan tool before condemning the control module.

Related powertrain codes

Frequently asked questions

Does P0205 mean my cylinder 5 injector is bad?

Not necessarily. P0205 is an electrical circuit fault — the majority of cases are caused by wiring damage or a corroded connector, not the injector itself. Test the circuit thoroughly before replacing any parts.

Can I drive with P0205?

If the MIL is steady and there is only a mild stumble, you can drive short distances cautiously. If the MIL is flashing, stop driving as soon as safe — an active severe misfire can destroy the catalytic converter within minutes.

Why do cylinders 5–8 only appear on certain engines?

Cylinders 5 through 8 physically exist only on V6 (some), V8, V10, and V12 engines. A P0205–P0208 code will never appear on a 4-cylinder engine.

How is P0205 different from P0305?

P0205 is an electrical fault on the injector control circuit — the ECM detected wrong voltage or current. P0305 is a combustion result fault — the crankshaft sensor detected a misfire event on cylinder 5. Both can occur together, but P0205 can be present even if the engine is not actively misfiring.

Disabling P0205 in software

RaceTune can permanently disable P0205 — 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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