P2149 indicates that the engine control module has detected an open circuit in the supply voltage feeding the fuel injectors of group B. This means the injectors are not receiving the required battery voltage to operate, which can prevent them from firing. The issue is usually in the power feed wiring, fuse, or connector rather than the injectors themselves or the PCM.
The fuse that protects the B‑group injector power circuit may have opened, removing voltage to the injectors.
A broken wire, chafed insulation, or corroded splice in the supply harness can create an open circuit between the fuse and the injector connectors.
The connector at the injector harness may have bent pins, moisture intrusion, or corrosion that interrupts the voltage feed.
Some vehicles use a separate driver module for injector groups; a failure inside this module can prevent the supply voltage from reaching the injectors.
Although uncommon, a failure in the PCM’s internal driver that controls the injector group B supply relay could cause an open circuit indication.
No. The PCM is rarely the cause of this code; the issue is almost always a blown fuse, open wiring, or faulty connector in the injector group B supply circuit. Replacing the PCM should only be considered after all wiring and fuse checks have been completed and confirmed good.
A failed injector itself usually does not trigger an open‑supply‑voltage code unless it causes the fuse to blow. The code primarily points to a loss of voltage at the injector power feed, so injector replacement is not the first step.
Driving is not recommended. Without proper voltage to the injector group B, the engine may misfire, lose power, or stall, which could lead to unsafe driving conditions or further damage.
A basic check of fuses, connectors, and voltage can be completed in 15‑30 minutes. More extensive wiring tests may add another hour, depending on accessibility.