What it means
The ECU detects an open or missing supply voltage on injector group B. The injectors on this bank cannot be energized, leading to misfire on the affected cylinders.
At a glance
- Usually lights the check-engine light
- Affects emissions; the car can fail an emissions test
- The engine or gearbox may go into limp mode
How it works
Injector group B has a shared supply circuit that powers its injectors, with the ECU controlling their individual operation. This code sets when the ECU detects an open circuit or missing supply voltage in group B, so the cylinders served by that group may misfire.
Common causes
Most likely first.
- Blown injector group B fuse
- Faulty injector supply relay
- Pin pushed back out of connector body
Symptoms
- Check engine light on
- Misfire or rough idle on the affected cylinder
- Increased fuel consumption
- Possible fuel smell or smoke from exhaust
How to diagnose it
- Record freeze-frame data and check related group B injector and misfire codes to identify when the supply disappeared.
- Use live data, if available, to identify misfires on cylinders served by group B and compare with any group A supply readings.
- Inspect the group B fuse, relay, connectors, and harness for a blown fuse, loose connection, corrosion, or a pushed-back pin.
- Check for group B supply voltage at the relevant connector and across the fuse and relay using the manufacturer’s test conditions.
- If power is absent, trace continuity through the group B circuit and relay path with the manufacturer’s wiring diagram to locate the open.
Common fixes
- Replace a blown group B injector fuse after checking for the cause.
- Reseat or repair a pushed-back, loose, or corroded group B connector pin.
- Repair an open or damaged group B supply wire.
- Replace a faulty injector supply relay if testing confirms its output is missing.
Can I keep driving?
Avoid driving if the engine is misfiring or running roughly because ongoing misfire can overheat and damage the catalytic converter. A stall or loss of power is possible, so arrange prompt diagnosis.
A code shows where the control module detected a fault, not always which part failed. Check the causes in order and confirm with a test before replacing parts. Have several codes? Check them together
This is a generic code: it means the same on every make. The car’s maker may add more detail in its own service information.