P2B01

Code

Generic P — Powertrain

Cylinder 2 Injection Pulse Performance

Brand: Generic

Type: P — Powertrain

Views: UK: 39 EN: 45 RU: 34

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Page language: EN

Causes

Faulty fuel injector (clogged, sticking, internal short)
Open/short or high-resistance wiring/harness to injector 2
Poor connector contact or corrosion at the injector connector
Faulty injector drive transistor or ECM output for cylinder 2
Low or unstable fuel rail/line pressure
Camshaft/crankshaft timing error or variable valve timing fault affecting injection timing

Symptoms

Check Engine Light (MIL) illuminated
Rough idle or vibration, especially at idle or low load
Misfire on cylinder 2 (possible misfire code P0302 present)
Reduced engine power and throttle response
Poor fuel economy and increased emissions
Fuel smell from exhaust or tailpipe wetting (if injector leaking)

What to check

Read stored DTCs and freeze frame data; note engine conditions when fault set
Check for related DTCs (misfire codes, fuel pressure, cam/crank sensor, injector circuit codes)
Monitor live data: injector pulse width (commanded), fuel trims, O2 sensor response, cylinder contribution/individ. misfire counters
Visually inspect injector 2 connector, wiring harness and PCM connector for corrosion, damage, or loose pins
Measure injector 2 resistance with multimeter and compare to other injectors and manufacturer spec
Backprobe injector connector during cranking/running to confirm injector drive voltage and ground switching

Signal parameters

Typical injector pulse width (idle): ~1–4 ms (varies by engine and load)
Typical injector pulse width (high load): can extend to 8–20 ms depending on engine and fueling strategy
Injector coil resistance: common ranges — low-impedance 2–5 Ω or high-impedance 12–16 Ω (check OEM spec)
Injector drive voltage: near battery voltage when open circuit (~11–14.5 V) and switched to ground by ECM when activated
Fuel rail/static pressure (port-injected gasoline engines): commonly ~40–70 psi (spec varies)
Expected behavior: commanded pulse should be present on scope/noid and consistent with other cylinders under same conditions

Diagnostic algorithm

Retrieve all stored and pending DTCs and view freeze frame. Note engine RPM, coolant temp, throttle position and fuel trims when code set.
Visually inspect wiring and connectors for injector 2; repair any damaged insulation, corrosion or loose pins.
Measure injector 2 DC resistance and compare to other injectors. If significantly out of range, remove and bench-test or replace injector.
Backprobe the injector connector with a noid light or scope while cranking/running to verify a proper pulse signal (presence, frequency and duration). Compare waveform/width to another cylinder.
Measure supply voltage at the injector connector with key on and engine running; verify good power and ground continuity to PCM.
Check fuel rail pressure at idle and under commanded load; confirm pressure meets spec and regulator/pump operation is normal.
Perform an active injector test or cylinder balance test using a scan tool: disable injector 2 and observe rpm/drop to confirm contribution. If condition follows injector when swapped, injector is suspect.
If electrical signal is missing or abnormal at PCM output, inspect PCM connector and grounds; consider PCM driver fault if wiring is good.
If injector pulses look normal but fuel delivery is poor, consider cleaning or replacing injector and re-test.
If mechanical issues suspected (low compression, timing faults), perform compression/leak-down and verify cam/crank timing/VVT operation.
After repairs, clear codes and road-test under same conditions to confirm the fault does not return.

Likely causes

Injector 2 electrical fault (open/short or poor ground)
Clogged or leaking injector causing inconsistent fuel delivery
Low fuel rail pressure or failing fuel pump/regulator
PCM driver failure for injector 2 or poor PCM ground
Timing/phasor fault causing injection timing mismatch

Fault status

⚠️ Status

PCM detected injector pulse performance for cylinder 2 outside expected parameters and stored P2B01. MIL may be on. The code indicates an injector or injector control issue for cylinder 2 but does not by itself identify the exact component.

🟡 Repair difficulty: Medium

⏱️ Diagnostic time: 1.0-3.0 hours

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