P2150–P2155 — Injector Group “B” Supply Voltage Circuit Faults

Category

Powertrain → Fuel System (Electronic Injector Control)

What it means (plain English)

Modern ECMs often split injectors into two groups (Group A & Group B) for power supply and control.

  • Group A = typically cylinders 1–3 (varies by platform)
  • Group B = typically cylinders 4–6 (or 4–8 on V8s)

Codes P2150–P2155 flag faults in the Group “B” injector supply voltage circuit:

  • P2150 — Circuit/Open
  • P2151 — Circuit Low
  • P2152 — Circuit High
  • P2153 — Circuit Range/Performance
  • P2154 — Circuit Intermittent
  • P2155 — Circuit Voltage Malfunction (manufacturer-defined on some engines)

Symptoms

  • MIL (Check Engine Light) illuminated
  • Hard starting or no-start (if multiple injectors can’t fire)
  • Severe misfire, rough idle
  • White or black smoke from unburned fuel
  • Poor fuel economy
  • Derate/limp mode likely

Priority Level

Very High —
Loss of injector Group “B” means multiple cylinders can’t fire properly. The truck may barely run or not start at all. This is a downtime-critical issue.

Common Causes

  • Open circuit in Group “B” injector harness
  • Wiring rub-through near valve cover, fuel rail, or ECM harness
  • Corroded or oil-soaked injector connectors
  • Short-to-ground (low voltage codes)
  • Short-to-voltage or regulator fault (high voltage codes)
  • Failing ECM injector driver (rare but possible)
  • Battery/charging faults (low voltage across groups)

How Pros Diagnose It (step-by-step)

  1. Scan tool check — confirm which Group “B” code(s) set (open, low, high, etc.).
  2. Visual inspection — look for chafed harnesses and damaged connectors.
  3. Check battery & alternator health — confirm proper voltage.
  4. Live data — monitor injector voltage during cranking and running.
  5. Continuity/resistance test — verify wiring from ECM to injector Group “B.”
  6. Voltage drop/load test — confirm no shorted injector pulling down supply.
  7. If wiring and connectors test good → suspect ECM injector driver fault.

Likely Fixes

  • Repair/replace damaged wiring harness
  • Clean or replace corroded connectors
  • Replace shorted injector(s)
  • Replace or repair ECM if driver failure confirmed
  • Correct charging system overvoltage (for “high” codes)

Related/Companion Codes

  • P2146–P2148 — Injector Group “A” Supply Voltage Circuit faults
  • P0201–P0208 — Individual injector circuit malfunctions
  • Battery/alternator faults (P0620–P0622)

Tech Notes (Quick Hits)

  • Cummins ISX/ISB — Group “B” wiring failures common near valve cover harness.
  • GM Duramax — corroded injector connectors are notorious for Group “B” faults.
  • Ford Powerstroke 6.4L/6.7L — often caused by oil intrusion into harness at injectors.
  • If multiple injectors drop together, always suspect group harness or ECM driver, not individual plugs.

Severity: Very High — Repair Immediately
Codes P2150–P2155 mean your truck has lost injector supply voltage to Group “B.” This takes multiple cylinders out of action, often leading to no-start or severe derate. Quick wiring or ECM repairs are critical to avoid downtime and costly roadside service.

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