Easy one-page printout for the garage or repair shop
This summary uses the existing diagnostic information shown in full below.
This code means that the car's computer found a problem with the fuel injector for cylinder 10. It's not giving the right amount of fuel.
The engine control module (ECM) has detected that the fuel injector for cylinder 10 is not delivering the correct small quantity of fuel needed for optimal performance.
The P12B3 code indicates that the adaptation values for the small quantity of fuel delivered by the injector in cylinder 10 are outside the acceptable range. This can affect engine performance and emissions.
• Engine misfire
• Poor fuel economy
• Check engine light on
• Faulty fuel injector
• Wiring or connection issues
• Fuel delivery problems
ECM: Engine Control Module
Injector: A component that sprays fuel into the engine's cylinders
• Check for any other related codes
• Inspect the wiring and connections to the injector
• Test the fuel injector for cylinder 10
• Replace the faulty injector
• Repair or replace damaged wiring
• Clean the fuel injector
• OBD-II scanner
• Multimeter
• Fuel injector tester
$200 - $500
Moderate
• BMW 7 Series
• Mercedes-Benz S-Class
• Audi A8
• Regular fuel system maintenance
• Use quality fuel
• Routine engine check-ups
Engine Performance
• Have the vehicle inspected by a professional
• Avoid hard driving until repaired
Check with the vehicle manufacturer for warranty coverage on injectors.
This code is often associated with high-mileage vehicles or those with fuel system issues.
Moderate – Addressing this issue promptly can prevent further engine damage.
Driving with a malfunctioning injector can lead to increased emissions and potential engine damage.
• Engine at operating temperature
• Vehicle idling
The fuel injector for cylinder 10 is located on the engine block, typically under the intake manifold.
Q: Can I drive with a P12B3 code?
A: It's not recommended as it can lead to further engine issues.
Q: How can I prevent injector issues?
A: Regular maintenance and using high-quality fuel can help prevent problems.
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Fitment Required · Vehicle-fitment part
Commonly relevant for misfire, ignition-efficiency, and some drivability-related repairs.
Misfire and ignition-related faults commonly involve spark plugs as part of the repair path.
Check the correct plug type, gap, and engine application for your vehicle.
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Fitment Required · Vehicle-fitment part
Relevant when the fault points toward ignition-coil performance or cylinder-specific ignition issues.
Some ignition faults involve coil performance or cylinder-specific coil problems.
Match the coil to your engine and confirm the failed component before ordering.
View options on AmazonThese parts may be related to this fault category, but a code by itself does not confirm exact fitment or guarantee that replacing a part will solve the problem.