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DTC codes / P21xx · Fuel and air metering / P2155

P2155Fuel Injector Group 'D' Supply Voltage Circuit/Open

P2155 indicates that the powertrain control module (PCM) has detected an open circuit or supply voltage fault in the fuel injector group 'D' circuit, which typically feeds a set of injectors on one bank or a specific group. The PCM monitors the voltage on the injector supply circuit and sets this code when the voltage falls outside the expected range, often due to a wiring issue, faulty injector, or poor connection.

SystemPowertrain
Code typeGeneric (all makes)
SeverityMedium
Fix difficultyIntermediate
AreaFuel and air metering

Symptoms you may notice

  • Illuminated check engine light (malfunction indicator lamp) with no other noticeable symptoms
  • Rough idle or misfire, especially if the affected injector group includes multiple cylinders
  • Engine hesitation or stumble during acceleration
  • Reduced engine power or limp mode in some vehicles
  • Poor fuel economy or increased emissions
  • Hard starting or stalling, particularly when the engine is cold

Common causes, most likely first

  1. Open or shorted wiring in the fuel injector group 'D' supply voltage circuit
  2. Corroded or loose electrical connector at one of the injectors in group 'D'
  3. Faulty fuel injector with an internal open coil or short
  4. Blown fuse or faulty relay that supplies power to the injector group
  5. Damaged PCM driver circuit for the injector group (less common)
  6. Rodent damage or chafed wiring harness causing an open circuit

How to diagnose and fix it

  1. Check for any stored diagnostic trouble codes (DTCs) and freeze-frame data to confirm the fault conditions
  2. Inspect the fuel injector group 'D' wiring harness and connectors for damage, corrosion, or looseness
  3. Test the injector supply voltage circuit for opens or shorts using a digital multimeter (DMM) and wiring diagram
  4. Measure the resistance of each fuel injector in group 'D' and compare to specifications
  5. Check the fuse and relay that provide power to the injector group and replace if faulty
  6. Perform a wiggle test on the harness while monitoring injector voltage to identify intermittent faults
  7. If all electrical checks pass, suspect the PCM and perform further diagnostics before replacement

Don't overlook injector group wiring

  • A common cause of P2155 is a chafed wire in the injector harness near the intake manifold or valve cover, often caused by vibration or heat damage.
  • The code may set intermittently and not illuminate the check engine light immediately; always check for pending codes if drivability issues are present.
  • Group 'D' injectors are often on one bank of a V-engine, so a single faulty injector can affect multiple cylinders and mimic other misfire codes.
  • Some vehicles use a shared power wire for the injector group, so a single bad connection can disable several injectors and cause a no-start condition.
  • Resistance testing of injectors can be misleading if the injector coil is temperature-sensitive; test both cold and hot if the fault is intermittent.

Can I keep driving with P2155?

Driving with P2155 is generally not recommended because the engine may run rough, misfire, or enter limp mode, which can damage the catalytic converter over time. If the vehicle is drivable, avoid heavy acceleration and have it diagnosed promptly.

Tools that help

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Guidance is general and written for all OBD-II vehicles. Exact tests and values vary by model, so confirm the fault before replacing parts.

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