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 detected a problem with the injector that puts fuel into cylinder 7. It's like when a water gun doesn't have enough pressure to shoot water properly.
The engine control module (ECM) has detected a low voltage condition in the high side circuit of the high-pressure fuel injector for cylinder 7.
The P31CC code indicates that the high side circuit for the high-pressure injector on cylinder 7 is experiencing a low voltage condition. This could be due to wiring issues, a faulty injector, or problems with the ECM itself. The high side circuit is responsible for providing the necessary voltage to the injector to ensure proper fuel delivery.
• Engine misfire
• Poor fuel economy
• Check Engine Light illuminated
• Faulty injector for cylinder 7
• Wiring issues or poor electrical connections
• Faulty ECM (Engine Control Module)
ECM: Engine Control Module, the computer that controls the engine's functions.
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 for proper operation.
• Repair or replace damaged wiring and connectors.
• Replace the faulty injector.
• Reprogram or replace the ECM if necessary.
• OBD-II scanner
• Multimeter
• Fuel injector tester
$200 - $600
Moderate
• Chevrolet Silverado
• GMC Sierra
• Cadillac Escalade
• Regularly inspect and maintain the fuel system.
• Use high-quality fuel to prevent injector clogging.
• Perform routine vehicle diagnostics.
Engine Performance
• Have the vehicle inspected by a professional mechanic.
• Avoid driving the vehicle if it exhibits severe symptoms.
• Regularly maintain the vehicle to prevent future issues.
Check with the vehicle manufacturer for warranty coverage on fuel injectors.
This code has been associated with issues in vehicles using direct fuel injection systems, which have become more common in recent years.
Moderate – Addressing this issue promptly can prevent further engine damage.
Driving with a misfiring engine can lead to increased emissions and potential safety hazards.
• Engine running at operating temperature
• Vehicle stationary
The injector for cylinder 7 is located on the engine block, typically on the passenger side of V8 engines.
Q: Can I drive with this code?
A: It's not recommended to drive for long periods with this code active, as it can lead to engine damage.
Q: How urgent is the repair?
A: Moderately urgent. It's best to address it soon to avoid further issues.
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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.