P2B00 code meaning
Cylinder 1 Injection Pulse Performance
Powertrain system Generic code P2Bxx codes Check engine light
What P2B00 means
P2B00 says the engine module could not confirm, with the engine past its cold-start phase, that injection pulses it commanded for cylinder 1 really happened. GM documents the check for its gasoline direct-injection engines: the ECM digitises the voltage across both injector wires and looks for the small flux signature the armature leaves when it lifts. If that opening trace is missing too often – 100 failures in 200 samples in the 2018 four-cylinder table, Type B, lamp after two trips – the pulse counts as lost. GM only runs it with at least 5 MPa rail pressure, 5 s engine run time and 10 % fuel in the tank. GM bulletins name P2B00 on the 2.7 L L3B (chafed engine harness) and the 1.2 L LIH (ECM software). The cold-start twin for cylinder 1 is P2B08.
P2B00 at a glance
- Check engine lightYes, usually on
- Emissions testCan fail
- Limp modeNot expected
- Repair difficultyMedium
- Typical labor0.3 to 4 hours
- Clears after repairAfter a drive cycle
Symptoms of P2B00
- Check engine light after the second faulty trip
- Rough running or misfire on cylinder 1 (P0301), sometimes no noticeable symptom
- With a harness short, several unrelated codes at once and possibly a no-start
Common causes of P2B00
- Most likelyEngine harness chafed through to ground (GM L3B – above the camshaft carrier or near the left shock tower)
- PossibleArmature or needle of the cylinder 1 injector sticking, so no opening signature appears
- PossibleOutdated ECM calibration (GM service update for the 1.2 L LIH)
- Less likelyHigh contact resistance at the cylinder 1 injector connector
Check the most likely causes first. Replacing parts by guesswork is the most expensive way to clear a code.
Parts involved
Fuel injector cylinder 1Injector wiringEngine control module
What each part of P2B00 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. |
| 00 | The exact fault in that area. |
What to do next
- Note P2B00 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 P2B00
What does P2B00 mean?
P2B00 means "Cylinder 1 Injection Pulse Performance". P2B00 says the engine module could not confirm, with the engine past its cold-start phase, that injection pulses it commanded for cylinder 1 really happened. It is a generic code, so it means the same on every make.
Is it safe to drive with P2B00?
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 P2B00 fail an emissions test?
Yes, it can. P2B00 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 P2B00 to fix?
Difficulty: medium. A typical repair takes 0.3 to 4 hours of work. This is a job for a workshop.
Will P2B00 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.