What it means
The control module detected a low electrical signal in the cylinder 12 injector B circuit. This indicates an electrical circuit condition; it does not by itself establish injector flow or cylinder fuel balance.
At a glance
- Usually lights the check-engine light
- Affects emissions; the car can fail an emissions test
How it works
The control module monitors the electrical signal in the injector B circuit for cylinder 12. This code sets when the signal is lower than expected, which can result from a short to ground, a poor connector, or an injector electrical fault; it does not establish whether the injector is delivering the right amount of fuel.
Common causes
Most likely first.
- Short to ground in wiring
- Damaged or corroded connector
- Injector electrical fault
Symptoms
- Check-engine light on
- Rough running or misfire
- Reduced engine power
- Increased fuel consumption
How to diagnose it
- Save the freeze-frame data and check for related injector or misfire codes to identify the conditions when the cylinder 12 circuit went low.
- Inspect the cylinder 12 injector B connector and harness for rubbed-through insulation, corrosion, loose pins, or signs of contact with ground.
- Use scan-tool data and the manufacturer's diagnostic information to confirm that injector B for cylinder 12 is the circuit reporting low.
- With the circuit safely isolated according to manufacturer procedures, test the wiring for a short to ground and check connector terminal fit.
- If the wiring and connector are sound, test the cylinder 12 injector B electrically against the manufacturer's specification.
Common fixes
- Repair wiring shorted to ground in the cylinder 12 injector B circuit.
- Clean or repair corroded, loose, or damaged injector B connector terminals.
- Replace the cylinder 12 injector B if testing confirms an electrical fault.
Can I keep driving?
If it runs smoothly, keep trips short and use light throttle until diagnosed. Rough running or a misfire can overheat and damage the catalytic converter; stop if the engine shakes badly or the check-engine light flashes.
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.