P2B0F Cold Start Cylinder 8 Injection Pulse Performance

P2B0F closes the cold-start series with cylinder 8, so it only appears on eight-cylinder engines; publicly GM documents it, in table 25OBDG06A for its 2025 V8 family (Type B, two trips, 50 to 100 samples). The ECM reads the voltage across the injector enable and command wires and treats a pulse as undelivered when no opening magnitude shows up during catalyst heating. The same table watches cylinder 8 in other ways too: the warm-running pulse check P2B07 and GM's own codes P10B1 and P10B2, which set when the total small-pulse compensation of that injector falls below or rises above its limit. One enabling condition is that the enrichment for brand-new engines is no longer active. No service bulletin naming P2B0F was found.

Likely causes

Symptoms

• Check engine light, frequently without driveability complaints
• With a real injector fault, rough cold idle and possibly misfire on cylinder 8 (P0308)

Repair estimate

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

Parts involved

Related codes

References: law.cornell.edu, gsi.ext.gm.com.