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 electricity going to a part that helps control the air flow to the engine. It's like if a toy car's battery isn't working right, so the car can't move properly.
The P303E code indicates that there is an issue with the supply voltage to the controlled upper air shutter, which is responsible for regulating airflow to the engine for optimal performance and efficiency.
The controlled upper air shutter is part of the vehicle's active grille shutter system, which adjusts the airflow to the engine based on speed and temperature conditions. The P303E code is triggered when the powertrain control module (PCM) detects an abnormal voltage reading from the shutter's supply circuit, indicating a potential electrical issue.
• Check Engine Light is on
• Reduced fuel efficiency
• Possible overheating at low speeds
• Faulty air shutter actuator
• Wiring issues such as open or short circuits
• Faulty PCM or software issue
PCM: Powertrain Control Module, the vehicle's engine control unit
Actuator: A device responsible for moving or controlling a mechanism or system
• Use an OBD-II scanner to confirm the code
• Inspect the wiring and connectors for damage or corrosion
• Test the air shutter actuator for proper operation
• Repair or replace damaged wiring or connectors
• Replace the faulty air shutter actuator
• Reprogram or replace the PCM if necessary
• OBD-II scanner
• Multimeter
• Screwdriver set
$150 - $500
Moderate
• Chevrolet Silverado
• GMC Sierra
• Cadillac Escalade
• Regular maintenance checks
• Inspect electrical connections periodically
• Keep the grille area clean and free of debris
Sensor Issue
• Do not ignore the Check Engine Light
• Consult a professional mechanic if unsure
• Avoid DIY repairs unless experienced
Check with the vehicle manufacturer for warranty coverage on emissions-related components.
This code has become more common with the introduction of active grille shutter systems in modern vehicles to improve aerodynamics and fuel efficiency.
Moderate – It's important to address this issue to maintain fuel efficiency and prevent potential engine overheating.
Driving with a malfunctioning air shutter can affect emissions and may not comply with environmental regulations.
• Vehicle at operating temperature
• Engine running at idle
The controlled upper air shutter is located at the front of the vehicle, integrated into the grille area.
Q: Can I drive with a P303E code?
A: It's possible to drive short distances, but it's best to fix the issue soon to avoid reduced fuel efficiency and potential overheating.
Q: How do I reset the Check Engine Light after repairs?
A: Use an OBD-II scanner to clear the code after ensuring the repairs are complete.
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