What it means
The supply voltage measured at injector group A is below the calibrated threshold. Either the supply is shorted to ground or the source voltage has collapsed during cranking or load.
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 A receives power through a shared supply circuit, and the ECU controls the injectors individually. This code sets when the measured supply voltage for group A falls below its calibrated threshold, which can prevent the affected injectors from operating reliably.
Common causes
Most likely first.
- Supply wire shorted to ground
- Weak battery, low cranking voltage
- Connector pins corroded - high contact resistance
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
- Save freeze-frame data and check related injector supply and misfire codes to learn whether the low voltage occurred during cranking, idling, or load.
- Check battery condition and charging-system data, then compare cranking voltage with the manufacturer’s specification because low source voltage can pull down the group A supply.
- Inspect group A’s fuse, relay, connectors, and wiring for a short to ground, corrosion, loose pins, or heat damage.
- Use live data or a meter to compare group A supply voltage with battery voltage under the conditions in the freeze frame.
- If voltage is low, isolate the supply circuit and test for excessive resistance or a short to ground using the manufacturer’s wiring diagram and test procedure.
Common fixes
- Clean or repair corroded or loose group A connector pins.
- Repair a supply wire shorted to ground or with excessive resistance.
- Replace a weak battery or repair a charging-system fault if system voltage is below specification.
- Replace a faulty group A supply relay or fuse connection if testing identifies it.
Can I keep driving?
Limit driving if the engine misfires or runs roughly, and avoid heavy acceleration because continued misfire can damage the catalytic converter. If it stalls or smells strongly of fuel, stop and have it checked before driving further.
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.