Easy one-page printout for the garage or repair shop
This summary uses the existing diagnostic information shown in full below.
This code means there's a problem with the part of the car that helps put fuel into the engine for cylinder number 2. It's like a broken straw that can't deliver the drink to your mouth.
The P21D0 code indicates a malfunction in the electrical circuit of the fuel injector for cylinder 2. This could mean the circuit is open or not working properly.
The P21D0 code is triggered when the Engine Control Module (ECM) detects an open circuit or a fault in the electrical circuit of the fuel injector labeled as 'B' for cylinder number 2. This could be due to wiring issues, a faulty injector, or a problem with the ECM itself.
• Check Engine Light is on
• Engine misfire or rough running
• Poor fuel economy
• Faulty fuel injector for cylinder 2
• Open or shorted wiring in the injector circuit
• Faulty Engine Control Module (ECM)
ECM: Engine Control Module
Injector: A device that sprays fuel into the engine's intake manifold or cylinders
• Use an OBD-II scanner to confirm the code.
• Inspect the wiring and connectors for cylinder 2 injector.
• Test the injector resistance and operation.
• Repair or replace damaged wiring or connectors.
• Replace the faulty fuel injector.
• Reprogram or replace the ECM if necessary.
• OBD-II scanner
• Multimeter
• Basic hand tools
$150 - $500
Moderate
• Ford F-150
• Chevrolet Silverado
• Toyota Camry
• Regular maintenance and inspection of the fuel system.
• Use high-quality fuel to prevent injector clogging.
• Check wiring and connectors for damage regularly.
Engine Performance
• Do not ignore the check engine light; have it diagnosed promptly.
• If experiencing rough idling, reduce driving until repaired.
• Consult a professional mechanic for accurate diagnosis.
Check with your vehicle's manufacturer for warranty coverage on fuel injectors and related components.
This code has been associated with fuel injector issues in various vehicle models, often due to wiring problems or injector failures.
Moderate – While the vehicle may still run, performance will be affected and could lead to more serious issues if not addressed.
Driving with a malfunctioning injector may lead to increased emissions and could fail emissions testing.
• Engine at operating temperature
• Vehicle in idle or during driving conditions
The fuel injector for cylinder 2 is typically located on the engine block, near the intake manifold for cylinder 2.
Q: Can I drive with a P21D0 code?
A: It's not recommended as it can lead to poor engine performance and potential damage.
Q: How do I know if my injector is faulty?
A: Symptoms include engine misfires, rough idling, and poor fuel economy.
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Universal · Digital multimeter
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Universal · Wire connectors and repair kit
Useful when diagnosis points toward damaged wiring, corroded terminals, or connector repairs.
Useful if diagnosis points toward damaged connectors, wiring, or terminal repairs.
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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.