Open or damaged wiring in the injector group 'B' supply circuit (broken wire, corroded connector, or chafed harness); Failed fuel injector with an open internal coil; Blown fuse or faulty relay supplying power to the injector group; Corroded or loose electrical connectors at the injectors or ECM; Faulty ECM driver for the injector supply circuit (less common); Short to ground or power in the supply circuit

DTC codes / P21xx · Fuel and air metering / P2149

P2149Fuel Injector Group 'B' Supply Voltage Circuit/Open

Q: What does code P2149 mean?

Fuel Injector Group 'B' Supply Voltage Circuit/Open. P2149 indicates that the engine control module (ECM) has detected an open circuit or supply voltage fault in the power feed to fuel injector group 'B', which typically covers one bank of injectors on V-configuration engines. The ECM monitors the voltage on the injector supply circuit and sets this code when the voltage falls outside the expected range, often because the circuit is open or shorted.

P2149 indicates that the engine control module (ECM) has detected an open circuit or supply voltage fault in the power feed to fuel injector group 'B', which typically covers one bank of injectors on V-configuration engines. The ECM monitors the voltage on the injector supply circuit and sets this code when the voltage falls outside the expected range, often because the circuit is open or shorted.

SystemPowertrain

Code typeGeneric (all makes)

SeverityMedium

Fix difficultyIntermediate

AreaFuel and air metering

Symptoms you may notice

Illuminated check engine light, often with no other noticeable symptoms
Rough running or misfire, especially under load or at idle
Reduced engine power or limp mode
Poor fuel economy
Hard starting or stalling
A noticeable fuel smell from the exhaust if injectors are not firing

Common causes, most likely first

Open or damaged wiring in the injector group 'B' supply circuit (broken wire, corroded connector, or chafed harness)
Failed fuel injector with an open internal coil
Blown fuse or faulty relay supplying power to the injector group
Corroded or loose electrical connectors at the injectors or ECM
Faulty ECM driver for the injector supply circuit (less common)
Short to ground or power in the supply circuit

How to diagnose and fix it

Check for any related technical service bulletins (TSBs) or recalls for the vehicle
Inspect the injector group 'B' supply circuit wiring and connectors for damage, corrosion, or looseness
Test the injector supply voltage at each injector connector with the key on, engine off, and compare to battery voltage
Check the fuse and relay that feed the injector group 'B' circuit
Measure the resistance of each injector in group 'B' and compare to specifications
Perform a voltage drop test on the supply circuit to identify excessive resistance
If all external checks pass, test the ECM driver circuit or substitute a known-good ECM for diagnosis

Don't overlook the injector supply circuit

A common mistake is replacing injectors without first checking the supply voltage; an open circuit in the shared power feed will disable all injectors in that group and mimic multiple injector failures.
The code can be set by a simple blown fuse that protects the injector power circuit, so always check fuses before condemning expensive components.
Corrosion inside a connector can create an open circuit that only appears when the engine is hot or vibrating, so wiggle-test the harness while monitoring voltage.
On some vehicles, the injector supply circuit is shared with other components like the ignition coils or mass airflow sensor, so a fault in those can also trigger P2149.
A faulty ECM is rarely the root cause; ensure all wiring and component tests are completed before considering ECM replacement.

Can I keep driving with P2149?

Driving with P2149 is not recommended because the engine may run poorly, stall, or enter limp mode, which can be unsafe in traffic. If you must drive to a repair shop, do so cautiously and avoid heavy acceleration or towing.

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.