Faulty or clogged fuel injector on cylinder 5; Damaged or corroded wiring or connector at the cylinder 5 injector; Open or shorted injector coil winding; PCM internal driver circuit fault for the injector; Low fuel pressure or restricted fuel supply affecting all cylinders but most noticeable on one; Mechanical engine issue such as low compression on cylinder 5

DTC codes / P2Bxx · Hybrid propulsion / P2B04

P2B04Cylinder 5 Injection Pulse Performance

Q: What does code P2B04 mean?

Cylinder 5 Injection Pulse Performance. P2B04 indicates that the powertrain control module (PCM) has detected an abnormal injection pulse performance for cylinder 5, meaning the electrical signal or the resulting fuel delivery does not match expected values. The PCM monitors the injector circuit and combustion efficiency, and when the pulse width or current feedback falls outside the calibrated range, it sets this code.

P2B04 indicates that the powertrain control module (PCM) has detected an abnormal injection pulse performance for cylinder 5, meaning the electrical signal or the resulting fuel delivery does not match expected values. The PCM monitors the injector circuit and combustion efficiency, and when the pulse width or current feedback falls outside the calibrated range, it sets this code.

SystemPowertrain

Code typeGeneric (all makes)

SeverityMedium

Fix difficultyIntermediate

AreaHybrid propulsion

Symptoms you may notice

Illuminated check engine light, often with no other noticeable symptoms
Rough idle or misfire sensation, especially when the engine is cold
Noticeable loss of power or hesitation during acceleration
Increased fuel consumption due to improper fuel delivery
Possible engine vibration or shaking at steady speeds

Common causes, most likely first

Faulty or clogged fuel injector on cylinder 5
Damaged or corroded wiring or connector at the cylinder 5 injector
Open or shorted injector coil winding
PCM internal driver circuit fault for the injector
Low fuel pressure or restricted fuel supply affecting all cylinders but most noticeable on one
Mechanical engine issue such as low compression on cylinder 5

How to diagnose and fix it

Perform a visual inspection of the cylinder 5 injector connector and wiring for damage or corrosion
Use a scan tool to check for related misfire codes and freeze-frame data to confirm the fault conditions
Measure the resistance of the cylinder 5 injector and compare it to the manufacturer's specification
Check fuel pressure and volume to rule out a supply issue
Swap the cylinder 5 injector with a known-good injector from another cylinder to see if the code follows
Perform a compression test or cylinder leak-down test to rule out mechanical problems
If the injector and wiring test good, diagnose the PCM driver circuit with an oscilloscope or replace the PCM as a last resort

Don't overlook injector wiring and connectors

A common oversight is assuming the injector itself is faulty when the real problem is a chafed wire or a corroded terminal that only acts up when the engine is hot or vibrating.
This code can be set by a fuel pressure problem that affects all cylinders, but cylinder 5 may be the first to show because of its position in the fuel rail or slightly lower compression.
A stuck-open injector can cause a rich condition and set P2B04, but it may also produce black smoke and fouled spark plugs that are often misdiagnosed as ignition problems.
Some vehicles use injector pulse width modulation for other functions, so a failing component like a fuel pump control module can indirectly cause this code without any injector fault.
Always check for technical service bulletins (TSBs) for the specific vehicle, as some manufacturers have known issues with injector connectors or PCM software that can trigger this code.

Can I keep driving with P2B04?

You can usually drive the vehicle short distances to a repair shop, but avoid heavy acceleration or towing, as prolonged driving with a misfiring cylinder can damage the catalytic converter. If the check engine light is flashing, stop driving immediately and seek professional help.

Tools that help

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Guidance is general and written for all OBD-II vehicles. Exact tests and values vary by model, so confirm the fault before replacing parts.