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 a sensor that helps control parts of the engine that move up and down. It's like a sensor that tells if a toy car's wheels are spinning correctly, but for your car's engine.
The P266C code indicates that the signal from the rocker arm actuator position sensor on bank 2 is lower than expected by the engine control module.
The rocker arm actuator position sensor monitors the position of the rocker arm in the engine. This sensor sends a signal to the engine control module (ECM) to help control the timing of the valves. When the ECM detects a low signal from this sensor on bank 2, it triggers the P266C code.
• Check Engine Light illuminated
• Engine misfire
• Reduced engine performance
• Faulty rocker arm actuator position sensor
• Wiring issues such as shorts or open circuits
• Faulty ECM
Rocker Arm: A component in the engine that helps open and close the valves.
Actuator: A device that causes a mechanism to operate.
• Use an OBD-II scanner to confirm the code.
• Inspect the wiring and connectors for damage or corrosion.
• Test the rocker arm actuator position sensor for proper operation.
• Replace the faulty rocker arm actuator position sensor.
• Repair or replace damaged wiring or connectors.
• Reprogram or replace the ECM if necessary.
• OBD-II scanner
• Multimeter
• Basic hand tools
$150 - $400
Moderate
• Honda Accord
• Acura TLX
• Chevrolet Silverado
• Regular maintenance and inspections
• Ensure proper engine oil levels and quality
• Avoid harsh driving conditions
Sensor Issue
• Have the vehicle inspected by a professional mechanic.
• Avoid driving the vehicle until the issue is resolved to prevent further damage.
Check with the vehicle manufacturer for specific warranty coverage related to engine sensors.
This code has been more prevalent in vehicles with advanced variable valve timing systems.
Moderate – It should be addressed soon to avoid potential engine damage.
Driving with this code may lead to increased emissions and potential engine damage.
• Engine running
• Warm engine temperature
The rocker arm actuator position sensor is typically located on the cylinder head of bank 2.
Q: Can I drive with a P266C code?
A: It's not recommended to drive with this code as it can lead to engine damage.
Q: How do I reset the P266C code?
A: After repairs, use an OBD-II scanner to clear the code. If the issue is fixed, it should not return.
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Universal · Digital multimeter
A solid entry-level multimeter for voltage, continuity, resistance, and basic electrical troubleshooting.
Helpful for checking voltage drops, grounds, and basic circuit health when modules are not communicating.
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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.