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P2B0B

Cold Start Cylinder 4 Injection Pulse Performance

During cold start, the ECM detects that the injection pulse on cylinder 4 does not produce the expected combustion result. Cold-start specific pulse calibration deviates from learned values.

  • Check engine light: Yes
  • Emissions related: Yes
  • Repair difficulty: medium

Common causes

Ordered by how often each turns out to be the cause.

  • Injector behaviour drifts at low temperatureCommon
  • Poor fuel atomization at cold startPossible

Parts involved

  • Fuel Injector Cyl 4
  • Cold Start Calibration

P2B0B is a generic OBD-II code defined by SAE J2012. Exact wording and diagnostic procedure vary by manufacturer and model. Code definitions are drawn from the public-domain OBDex dataset; the workshop notes are our own.