P2C58

Code

Generic P — Powertrain

Cylinder 4 Fuel Injector B Offset Learning At Min Limit

Brand: Generic

Type: P — Powertrain

Views: UK: 19 EN: 31 RU: 21

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Page language: EN

Causes

Injector B on cylinder 4 producing less fuel than expected (stuck/partially clogged or restricted)
Low injector drive current due to wiring fault (short to ground, high resistance, poor connection)
Open or shorted injector circuit or corroded connector pins
Low fuel pressure or supply issue reducing injector flow
PCM/ECM software or internal fault
Mechanical engine issue on cylinder 4 (low compression, air leak)

Symptoms

Malfunction Indicator Lamp (MIL) illuminated
Persistent or intermittent misfire on cylinder 4 (rough idle, stumble)
Reduced engine power or hesitation under load
Higher-than-normal exhaust emissions or failed emissions test
Possible poor fuel economy
Long crank or hard start in extreme cases

What to check

Read freeze frame and live data with a capable scan tool; note learned offset value, fuel trim, injector pulse width, and misfire counters for cylinder 4
Compare learned offset for cylinder 4 to other cylinders and note if at or near minimum limit
Visual inspection of injector 4 connector for corrosion, bent pins, or damage
Backprobe injector connector: verify 12V (or battery voltage) supply and proper ground/driver signal while cranking and running
Measure injector coil resistance at ambient temperature and compare to spec (manufacturer spec)
Wiggle wiring harness while monitoring live data for changes (intermittent wiring fault)

Signal parameters

Injector coil resistance (ohms) — compare to spec
Injector pulse width (ms) during various conditions (idle, commanded)
Supply voltage at injector connector (approx. battery voltage, ~12V)
Injector driver duty cycle/current if measured by diagnostic tool
Long-term learned offset value (reported by PCM) — currently at/near minimum limit
Short-term and long-term fuel trims (%) and per-cylinder trims if available

Diagnostic algorithm

Connect scan tool and record freeze frame, learned offset value, per-cylinder fuel trims, pulse widths and misfire data
Inspect injector 4 connector and wiring for damage, corrosion, or loose terminals; repair as needed
With ignition off, measure injector 4 coil resistance; compare to manufacturer spec. If out of range, replace injector
Reconnect and backprobe connector; with engine cranking/running verify injector supply voltage and driver signal (switching to ground) and compare to another cylinder
If wiring/connector suspect, perform continuity and resistance checks between injector connector and PCM pin; repair shorts/opens
Perform a fuel pressure/flow test; if pressure is low, diagnose fuel pump, filter, regulator, or supply issues
If electrical and fuel supply are good, swap injector 4 with a known-good injector from another cylinder and clear codes; road test to see if code follows the injector
If problem follows the injector, replace the injector and re-learn offsets if required; if problem stays on cylinder 4, perform compression/leak-down test and inspect for mechanical issues
After repairs, clear codes and perform drive cycle or injector offset relearn per manufacturer procedure; verify learned offset returns to normal range and no MIL returns
If wiring and injector check out and issue persists, consider PCM/ECM diagnosis, reflash, or replacement only after eliminating harness and injector faults

Likely causes

Dirty or partially clogged injector on cylinder 4
Corroded/loose connector or poor ground at injector 4
Wiring harness short to ground or high resistance in injector 4 circuit
Low fuel rail pressure or failing fuel pump/regulator
Injector driver fault in PCM (less common)

Fault status

⚠️ Status

PCM detected Cylinder 4 Fuel Injector B offset learning value at or beyond minimum limit — indicates the adaptive compensation reached the lower threshold for that injector and further learning cannot correct the condition.

🟡 Repair difficulty: Medium

⏱️ Diagnostic time: 0.5-2.5 hours