Fault codeP2149

MODERATE

Fuel Injector Group B Supply Voltage Circuit/Open

What this code means

Fuel Injector Group B Supply Voltage Circuit/Open.

P2149 is a generic code: it means the same thing on every make. P2149 belongs to family P21xx — Electronic throttle and mixture. Its page explains how to read a code and groups all its codes by part.

Type of fault

The control unit no longer sees continuity in this control circuit: a broken wire, an unplugged connector, or an open winding in the component. A multimeter checks both the component's resistance and the continuity of the wires.

Fuel injector

Each injector is an electric valve that sprays fuel into the intake or straight into the cylinder. The control unit opens it for a few milliseconds per cycle and monitors the current that flows through its coil.

What you notice

A cylinder that no longer gets fuel misfires: shaking, loss of power, the warning light flashing in serious cases. An injector that stays open floods the cylinder and can damage the engine.

How to check it

For an electrical fault, check the injector's connector and wiring first, then its coil resistance with a multimeter, comparing with the other injectors. Swapping two injectors between cylinders shows whether the fault follows the injector or stays with the wiring.

Watch it live in Klaro

With an OBD2 adapter plugged in, these live readings show the part at work, when your car reports them:

Short term fuel trim bank 1
Long term fuel trim bank 1
Engine fuel rate

What to do

Have it checked this week. The car remains usable, but the fault will not clear itself and will fail the roadworthiness test.

Clearing a code switches the light off but repairs nothing: if the fault remains, the code comes back. Clearing a fault code yourself →

How to read this code

PPowertrain
2standardised code
1Electronic throttle and mixture
49P2149