Easy one-page printout for the garage or repair shop
This summary uses the existing diagnostic information shown in full below.
This means that the computer in your car is having trouble controlling the fuel injector for cylinder number 7. It's like when you try to turn on a light, but the switch isn't working right, so the light doesn't turn on properly.
The engine control module (ECM) monitors the voltage and current in the injector circuit for each cylinder. If it detects that the voltage is too low in the circuit for cylinder 7, it triggers this error code.
P3125 indicates that the ECM has detected a low voltage condition in the low side circuit of the high-pressure fuel injector for cylinder 7. This could be due to a short circuit, a faulty injector, or a wiring issue.
• Engine misfire
• Reduced engine performance
• Check engine light illuminated
• Faulty fuel injector for cylinder 7
• Wiring issues such as a short or open circuit
• Faulty ECM or injector driver
ECM: Engine Control Module
Injector: A device that sprays fuel into the engine's cylinders
• Use an OBD-II scanner to confirm the code.
• Inspect the wiring and connectors for cylinder 7 injector.
• Test the injector resistance and operation.
• Repair or replace damaged wiring or connectors.
• Replace the faulty injector for cylinder 7.
• Replace or reprogram the ECM if necessary.
• OBD-II scanner
• Multimeter
• Injector tester
$150 - $500
Moderate
• Toyota Prius
• Lexus RX
• Chevrolet Silverado
• Regular maintenance and inspection of fuel system components
• Ensure proper electrical connections
• Use quality fuel to prevent injector clogging
Engine Performance
• Have a professional mechanic inspect the vehicle.
• Avoid driving the car if the engine is running rough.
Check with the vehicle manufacturer for warranty coverage on fuel injectors.
This code has been more common in vehicles with direct fuel injection systems.
Moderate – It should be addressed soon to prevent further engine performance issues.
Ignoring this code can lead to increased emissions and potential engine damage.
• Engine at operating temperature
• Vehicle idling or under load
The fuel injector for cylinder 7 is located on the engine, typically near the intake manifold.
Q: Can I drive my car with code P3125?
A: It's not recommended to drive with this code as it can lead to engine performance issues.
Q: How can I prevent injector issues?
A: Regular maintenance and using quality fuel can help prevent injector 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.