P2C58: Cylinder 4 Fuel Injector B Offset Learning At Min Limit

What it means

The learned offset for fuel injector B on cylinder 4 has reached its minimum limit. The code alone does not establish whether injector flow is above or below nominal.

At a glance

• Usually lights the check-engine light
• Affects emissions; the car can fail an emissions test

How it works

The engine control module learns a correction for injector B serving cylinder 4 to account for how much fuel that injector delivers. This code sets when the learned correction reaches its minimum allowed limit; it does not by itself prove whether fuel delivery is too high or too low.

Common causes

Most likely first.

1. Injector partially clogged - reduced flow
2. Local rail pressure drift on this injector

Symptoms

• Check engine light on
• Misfire or rough idle on the affected cylinder
• Increased fuel consumption
• Possible fuel smell or smoke from exhaust

How to diagnose it

1. Check freeze-frame data and live misfire or cylinder-balance data to confirm the fault is associated with cylinder 4.
2. Inspect injector B's connector and wiring at cylinder 4 for loose pins, corrosion, chafing, or heat damage.
3. Compare commanded and actual fuel-rail pressure under the conditions in the freeze frame to look for pressure drift affecting that injector.
4. Check cylinder 4's injector operation and contribution using the vehicle's supported scan-tool tests.
5. If the fault remains localized to injector B on cylinder 4, have its flow and leakage checked using the manufacturer's procedure and specification.

Common fixes

• Repair a loose, corroded, or damaged cylinder 4 injector B connector or wiring.
• Address a fuel-rail pressure control problem if measured pressure is outside the manufacturer's specification.
• Clean or replace injector B on cylinder 4 if testing confirms restricted flow.
• Clear the code and verify cylinder 4 operation and injector learning after the repair.

Can I keep driving?

If the engine runs smoothly and the warning light is steady, limit driving and arrange diagnosis soon because a cylinder 4 fueling fault can raise emissions and fuel use. Stop driving if the light flashes, the engine misfires badly, or you notice a strong fuel smell or exhaust smoke; continued operation can damage the catalytic converter.