P2B05 code meaning
Cylinder 6 Injection Pulse Performance
Powertrain system Generic code P2Bxx codes Check engine light
What P2B05 means
P2B05 marks missed injection pulses on cylinder 6 outside the cold-start window; on a six-cylinder engine this is the last cylinder in the order of numbers. No manufacturer documents P2B05 publicly as a stand-alone check. GM's 2025 V8 calibration (25OBDG06A/06B) lists it only in the support tables shared by the pulse family. One of them shows why the check is tied to split injection: double or triple pulses are allowed only up to about 3,000–3,600 rpm, depending on mode and injector energy profile, and per GM's 2018 definitions single-pulse data are evaluated below 5,000 rpm. A fault therefore tends to show at low and medium speed. The injector of cylinder 6 is first suspect, wiring second; the cold-start counterpart is P2B0D.
P2B05 at a glance
- Check engine lightYes, usually on
- Emissions testCan fail
- Limp modeNot expected
- Repair difficultyMedium
- Typical labor0.5 to 5 hours
- Clears after repairAfter a drive cycle
Symptoms of P2B05
- Check engine light
- Slight shaking at idle or low speed, misfire on cylinder 6 (P0306)
Common causes of P2B05
- Most likelyDeposits or wear on the cylinder 6 injector hampering small pulses
- PossibleContact problem at the injector 6 plug
- Less likelyInjector driver or voltage sensing in the ECM faulty
Check the most likely causes first. Replacing parts by guesswork is the most expensive way to clear a code.
Parts involved
Fuel injector cylinder 6Injector wiringEngine control module
What each part of P2B05 means
| P | Powertrain system: engine, fuel system, ignition, emissions and transmission. |
| 2 | Generic code (second SAE range): it means the same on every make. |
| B | Area: hybrid propulsion. |
| 05 | The exact fault in that area. |
What to do next
- Note P2B05 and any other codes stored with it: several codes together often point to one cause.
- Check for loose connectors and damaged wiring around the parts the code names.
- Check open recalls for your car: some faults are fixed for free by the dealer. Enter your VIN.
- Clear the code only after the repair. If it comes back, the fault is still there.
Buying a used car? Scan it for stored codes before you pay. A recently cleared memory can hide a problem.
Questions about P2B05
What does P2B05 mean?
P2B05 means "Cylinder 6 Injection Pulse Performance". P2B05 marks missed injection pulses on cylinder 6 outside the cold-start window; on a six-cylinder engine this is the last cylinder in the order of numbers. It is a generic code, so it means the same on every make.
Is it safe to drive with P2B05?
Usually yes, for a short time, if the check engine light is steady and the car drives normally. If the light flashes or the car runs badly, stop and have it checked.
Will P2B05 fail an emissions test?
Yes, it can. P2B05 is emissions-related, so most inspection programs fail a car while it is stored or while the check engine light is on.
How hard is P2B05 to fix?
Difficulty: medium. A typical repair takes 0.5 to 5 hours of work. This is a job for a workshop.
Will P2B05 clear itself after the repair?
After the repair the car has to complete a drive cycle (a mix of city and highway driving) before the test runs again. Until then the readiness monitor shows "not ready", which can fail an inspection.