P02F6

Code

Generic P — Powertrain

Cylinder 9 Injector Circuit Range/Performance

Brand: Generic

Type: P — Powertrain

Views: UK: 28 EN: 35 RU: 27

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Page language: EN

Causes

Open or short in injector wiring harness to cylinder 9
Poor or corroded connector at injector or harness
Failed fuel injector (stuck, leaking, weak spray)
Faulty injector driver or ground inside ECM/PCM
Low or intermittent fuel rail pressure or delivery problem
PCM/ECM software or internal fault

Symptoms

Check Engine Light (MIL) illuminated
Rough idle or misfire on cylinder 9
Reduced power, hesitation, or poor acceleration
Increased fuel consumption or black smoke
Possible limp-home mode or reduced performance limit

What to check

Retrieve freeze-frame and live data with a scan tool; compare injector pulse width/current for cylinder 9 to other cylinders
Visual inspection of injector connector and wiring for damage, corrosion, or loose pins
Measure injector electrical resistance at the injector connector and compare to specifications
Back-probe injector signal while cranking/running to check voltage/pulse and ground switching
Use a noid light or oscilloscope to verify injector drive waveform
Check fuel rail pressure and supply to rule out fuel delivery issues

Signal parameters

Injector coil resistance: typical low-impedance injectors ~1.0–3.0 ohms; high-impedance injectors ~10–18 ohms (check manufacturer spec)
Supply voltage at injector: approx. battery voltage (~11–14 V) on the constant feed terminal
Driver-side switching: pulsed ground or pulsed positive from ECM — expect 0–12 V switching on the driver pin
Typical pulse width at idle: ~1–3 ms; under load up to ~10–15 ms (varies by engine)
Pulse frequency varies with engine speed; waveform should be consistent with other cylinders
No excessive voltage spikes (use scope), and waveform should show clean switching edges and expected duty cycle

Diagnostic algorithm

Read and record all codes and freeze-frame data. Confirm P02F6 is active or historical.
Compare live injector parameters for cylinder 9 vs adjacent cylinders using a scan tool (pulse width, commanded injector duty, trim).
Perform a visual inspection of the harness and connector for cylinder 9; repair obvious damage or corrosion.
With ignition off, disconnect injector connector and measure injector resistance at the injector pins; compare to spec.
Back-probe the harness connector with ignition ON (engine off) and while cranking/running; verify feed voltage and switching signal from ECM.
Use a noid light or oscilloscope on the injector connector while cranking/running to confirm injector is being driven and waveform shape matches other cylinders.
If wiring and connector are good but injector shows abnormal behavior, swap the suspect injector with a known-good injector from another cylinder and recheck code/live data to see if fault follows the injector.
If fault follows wiring (stays on cylinder 9 after injector swap), trace and test continuity/resistance between the injector connector and the ECM pin; repair any shorts/opens.
If wiring and injector are good and fault remains on the same circuit, test or inspect the ECM driver output (may require dealer-level tools or ECM bench testing); consider ECM replacement only after all other causes are eliminated.
Check fuel pressure and engine mechanical condition (compression/leakdown) if electrical tests are normal but performance issues persist.
Clear codes after repairs and perform a test drive/operate engine under varied conditions to verify the repair. Monitor for recurrence.

Likely causes

Open, short, or high resistance in the injector harness/connector for cylinder 9
Failed/collapsed injector (electrical or mechanical)
Corroded or loose connector at the injector
Faulty injector driver in the ECM (less common)

Fault status

⚠️ Status

P02F6 — Cylinder 9 Injector Circuit Range/Performance. ECM detected injector circuit or injector operation for cylinder 9 outside expected parameters.

🟡 Repair difficulty: Medium

⏱️ Diagnostic time: 1.0-3.0 hours