P02EF

Code

Generic P — Powertrain

Cylinder 2 Injector Circuit Range/Performance

Brand: Generic

Type: P — Powertrain

Views: UK: 25 EN: 40 RU: 30

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Page language: EN

Causes

Poor electrical connection at the injector (corrosion, loose pin, damaged terminal)
Wiring harness damage (short to power, short to ground, high resistance, intermittent open)
Faulty fuel injector (electrical or internal hydraulic issue)
Low or high rail fuel pressure or blocked injector making flow out of expected range
PCM/ECM driver or software fault
Contaminated or mechanically sticking injector

Symptoms

MIL (check engine light) illuminated
Rough idle or engine vibration, especially at idle
Reduced power and poor acceleration
Cylinder-specific misfire codes (e.g., P0302) or intermittent misfire
Poor fuel economy and increased emissions
Hard starting or extended crank time in some cases

What to check

Read and record freeze frame and all stored codes; note drive conditions when code set
Perform visual inspection of wiring harness and connector for cylinder 2 injector
Check injector connector pins for corrosion, bent pins, or poor fit
Measure injector coil resistance at the connector and compare to spec
Backprobe connector while cranking/running to verify reference voltage and driver pulse
Use a noid light or oscilloscope to verify injector pulse waveform and current draw

Signal parameters

Expected injector coil resistance: typically 0.5–3.0 ohms (high-current injectors) or 11–16 ohms (low-current injectors) — check vehicle spec
Connector reference voltage: typically battery voltage on one pin (constant) and switched/pulsed ground from driver
Injector pulse width while idling: commonly 1–5 ms depending on engine load
Injector drive waveform: clean square/driver pulse on voltage or current waveform; current draw ramp indicates proper operation
Fuel rail pressure: manufacturer specified nominal pressure (example: 40–90 psi for many systems) — verify against spec

Diagnostic algorithm

Read codes and freeze frame; record conditions. Clear codes and attempt to reproduce.
Visually inspect cylinder 2 injector connector, wiring harness, and nearby components for damage, heat, or fluid contamination.
With ignition off, unplug connector and measure injector coil resistance. Compare to spec. Replace if out of range.
Reconnect and backprobe injector connector. With key ON/cranking, verify reference voltage/power supply to injector.
Start engine or crank while observing with a noid light or oscilloscope to confirm injector pulse and waveform. Note irregularities (weak/no pulse, erratic waveform, abnormal current profile).
Check fuel rail pressure and flow. Low or fluctuating rail pressure can cause abnormal injector performance readings.
Swap the suspect injector with a known-good injector from another cylinder (if practical). If code moves to the other cylinder, the injector is likely faulty.
Perform wiggle test and continuity/resistance check on wiring from injector connector to PCM pin; repair any high-resistance joints or shorts.
Inspect and test PCM driver outputs for cylinder 2 (compare to other cylinder outputs). Repair PCM only after ruling out wiring and injector.
If mechanical injector issues are suspected (sticking, leaking, clogged tip) remove and bench-test or flow-test the injector, then clean or replace as required.
After repairs, clear codes and road test under similar conditions to confirm the fault does not return.

Likely causes

Corroded or loose connector at cylinder 2 injector
High resistance in harness between injector and PCM (broken wire, chafing)
Failed injector (electrical coil failure or internal sticking)
Fuel pressure or flow abnormality affecting only cylinder 2 (partial blockage or return leak)

Fault status

⚠️ Status

Malfunction Indicator Lamp (MIL) illuminated. Engine control module detected abnormal cylinder 2 injector performance/range. May cause misfire, rough running, reduced power, and higher emissions. Further diagnosis required to identify electrical, mechanical, or PCM causes.

🟡 Repair difficulty: Medium

⏱️ Diagnostic time: 1.0-2.5 hours

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