Powertrain, generic (extended)

P2B00 Cylinder 1 Injection Pulse Performance

Check engine lightOn
EmissionsRelevant
Drive cycleRequired
Limp modeNo

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 petrol 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.

Likely causes

Engine harness chafed through to ground (GM L3B – above the camshaft carrier or near the left shock tower)
Armature or needle of the cylinder 1 injector sticking, so no opening signature appears
Outdated ECM calibration (GM service update for the 1.2 L LIH)
High contact resistance at the cylinder 1 injector connector

Symptoms

  • 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

Repair estimate

DifficultyMediumWorkshop job
Parts and labour€50–900
Time0.3–4 h

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

Parts involved

fuel injector cylinder 1injector wiringengine control module

Related codes

P2B08P2B01P2B96P02EEP0201P0301

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