Powertrain, generic (extended)

P2B03 Cylinder 4 Injection Pulse Performance

Check engine lightOn

EmissionsRelevant

Drive cycleRequired

Limp modeNo

With P2B03 the engine module reports that cylinder 4 injection pulses went unconfirmed after warm-up: the coil voltage showed no proof of the armature moving. In GM's lists the code belongs to four-cylinder direct-injection engines – the three-cylinder tables end at P2B02 – and GM's 2025 four-cylinder table needs 50 to 100 samples for a Type B verdict with two trips. GM engineering information PIE0808 (Colorado/Canyon of model years 2023–2024 with 2.7 L) collects P2B03 with the offset-learning limit codes P10A9/P10AA of the same cylinder and the circuit code P02F1; steps are checking the harness near the turbo actuator, unplugging the fuel rail connector for 60 s and a 10-mile test drive. P2B03 also appears in the L3B harness bulletins. Cold start: P2B0B.

Likely causes

Harness chafed near the turbo actuator or elsewhere on the engine (GM 2.7 L)

Poor contact in the fuel rail injector connector

Cylinder 4 injector worn or sticking

Symptoms

Lamp on after the second faulty trip
Possibly misfire on cylinder 4 (P0304) or under load
Further injector codes of the same cylinder stored at the same time

Repair estimate

DifficultyMediumWorkshop job

Parts and labour€50–900

Time0.5–4 h

Typical range across vehicles; the real cost depends on what the testing finds.

Parts involved

fuel injector cylinder 4injector wiringengine control module

References: law.cornell.edu, gsi.ext.gm.com, static.nhtsa.gov.