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.
Medium severity. Can I keep driving?If the car is running normally, drive in moderation to a repair shop. If it loses power or another warning appears, do not continue.
Cylinder 4 is numbered according to the manufacturer: check your engine's manual before working on it.
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
Most 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
What to check, in order
Start with the simplest. You can tick off each step.
Good to know
- Repair difficulty: medium
- It affects emissions.
What each character of P2B03 means
- P: Powertrain: engine and transmission
- 2: Generic code: same on every make
- B: Subsystem depends on the code range
- 03: Specific fault in that system
Frequently asked questions
Can I keep driving with code P2B03?
If the car is running normally, drive in moderation to a repair shop. If it loses power or another warning appears, do not continue.
What causes code P2B03?
The most common causes are: 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.
Related codes
- P2B0BCold Start Cylinder 4 Injection Pulse Performance
- P2B02Cylinder 3 Injection Pulse Performance
- P2B04Cylinder 5 Injection Pulse Performance
- P2B96Injection Pulse Performance
- P02F1Cylinder 4 Injector Circuit Range/Performance
- P0204Cylinder 4 Injector A Circuit/Open
- P0304Cylinder 4 Misfire Detected
Sources
Values and procedures vary by manufacturer. If it affects brakes, steering, fuel or high voltage, see a professional. Updated: 2026-11-04. How we build these pages.