P0205

Code

Generic P — Powertrain

Cylinder 5 Injector A Circuit

Brand: Generic

Type: P — Powertrain

Views: UK: 44 EN: 110 RU: 68

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Page language: EN

Causes

Open or shorted injector wiring (chafed, broken, pinched)
Corroded or loose injector connector or terminal
Failed fuel injector (internal short or open)
Faulty PCM/ECM injector driver transistor
Poor battery/ground connection or blown fuse/relay in injector supply
Aftermarket wiring, recent repairs, or connector contamination

Symptoms

Check Engine Light (MIL) illuminated
Misfire or rough running focused on cylinder 5
Reduced engine power or hesitation under load
Poor fuel economy
Difficulty starting or increased emissions
Code may be intermittent or present continuously

What to check

Read freeze frame and live data with a scan tool to confirm related freeze frame and misfire P0305
Visually inspect injector harness, connector and pins at cylinder 5 for damage, corrosion, contamination or pushed-out pins
Check related fuses and relays for injector power/supply
Wiggle test wiring and connector while monitoring data/engine response for intermittent faults
Swap cylinder 5 injector with a known good injector (another cylinder) and see if the code follows the injector
Back-probe injector connector to check for supply voltage and switching/ground signal while cranking/running

Signal parameters

Injector coil resistance: typical ranges - high-impedance injectors ≈ 12–16 Ω; low-impedance (peak-and-hold) injectors ≈ 2–4 Ω (spec varies by vehicle)
Supply voltage at injector harness (key ON): near battery voltage (~11–14 V) on the supply terminal
Command side: PCM switches the ground side (or positive) — pulsed waveform when running (observe with oscilloscope or lab scope)
Pulse width and frequency vary with engine speed/load; common pulse widths ~1–10 ms depending on operating conditions

Diagnostic algorithm

Connect a scan tool and confirm P0205 and any related codes (e.g., P0305). Record freeze-frame/test results.
Perform a visual inspection of the injector wiring, connector and pins at cylinder 5. Repair any visible damage.
With ignition OFF, disconnect harness and measure injector coil resistance between injector terminals. Compare to manufacturer spec. If out of range, replace injector.
With key ON (engine off) back-probe the injector supply terminal: verify battery voltage present. If no supply, check fuses/relays and harness for open.
Start engine or crank while back-probing the command terminal: confirm the PCM is switching (pulsed ground or voltage). Use a lab scope for a clear waveform. If no switching signal but supply present, suspect PCM or wiring open between PCM and injector.
Perform a wiggle test on harness/connectors while observing live data or engine behavior to find intermittent faults.
Swap the suspect injector with another cylinder (e.g., swap 5 with 4). If code follows the injector, replace the injector. If code stays on cylinder 5, focus on wiring/PCM.
Check for short to power/ground between injector harness and chassis battery using an ohmmeter or fused test light technique (follow manufacturer-safe procedures).
If wiring and injector are good, check PCM outputs and inspect PCM grounds/power. Repair or replace PCM only after confirming output driver failure with proper tools and procedures.
Clear codes and perform a road test to verify repair. Re-scan to confirm no return of P0205.