Powertrain, generic (extended)

P2B0E Cold Start Cylinder 7 Injection Pulse Performance

Check engine lightOn

EmissionsRelevant

Drive cycleRequired

Limp modeNo

P2B0E is the cylinder 7 entry of the cold-start pulse check. On engines that fire two or three short injections per cycle while heating the catalyst, the ECM expects each of them to show an opening signature on the injector feedback voltage; for cylinder 7 too many did not. GM's 2025 V8 supporting tables (25OBDG06B) show how the pulse count is chosen: double pulses are permitted up to 3,600 rpm and triple pulses up to 3,000 rpm, depending on the injector energy profile. The summary code P2B95 adds up the share of missed pulses over all cylinders once per trip, whereas P2B0E names the single cylinder (Type B, 50 to 100 samples, table 25OBDG06A). CARB phases this split-pulse check in over model years 2026 to 2028. The warm-running counterpart is P2B06.

Likely causes

Cylinder 7 injector not lifting on the very short split pulses (deposits, armature wear)

Enable or command wire of injector 7 damaged, falsifying the measured voltage

ECM software with an overly strict opening-signature evaluation

Symptoms

Warning lamp after the second faulty cold start
Slight shaking right after a cold start, often nothing noticeable

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 7injector wiringengine control module

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