Easy one-page printout for the garage or repair shop
This summary uses the existing diagnostic information shown in full below.
Your car has a part that helps reduce pollution called the EGR valve. This code means the sensor that checks this part is saying something is wrong because it's getting too much power or a signal that's too high.
The P0406 code is triggered when the Engine Control Module (ECM) detects a high voltage signal from the Exhaust Gas Recirculation (EGR) position sensor circuit.
The EGR system helps reduce nitrogen oxide emissions by recirculating a portion of the exhaust gases back into the engine cylinders. The EGR position sensor provides feedback to the ECM about the position of the EGR valve. A 'circuit high' condition indicates that the sensor is sending a voltage signal higher than the expected range.
• Check Engine Light is on
• Poor engine performance
• Increased emissions
• Rough idling
• Faulty EGR position sensor
• Wiring issues such as short to power or broken wires
• Faulty EGR valve
• ECM issues
EGR: Exhaust Gas Recirculation
ECM: Engine Control Module
• Use an OBD-II scanner to confirm the code.
• Visually inspect the EGR valve and sensor for damage.
• Check the wiring and connectors for signs of damage or corrosion.
• Test the EGR position sensor with a multimeter.
• Replace the EGR position sensor if faulty.
• Repair or replace damaged wiring or connectors.
• Replace the EGR valve if it is malfunctioning.
• Update or reprogram the ECM if necessary.
• OBD-II scanner
• Multimeter
• Socket set
$150 - $400
Moderate
• Ford F-150
• Chevrolet Silverado
• Toyota Camry
• Regular maintenance of the EGR system
• Use quality fuel to reduce carbon buildup
• Inspect wiring and connectors periodically
Sensor Issue
• Have the issue diagnosed and repaired promptly to avoid further engine problems.
• Consider using a fuel additive to clean the EGR system.
Check your vehicle's warranty for coverage on emission-related components.
This code has been common in vehicles with EGR systems, particularly as they age and carbon buildup occurs.
Moderate – While the car may still be drivable, it can lead to increased emissions and potential engine performance issues.
Driving with a malfunctioning EGR system may not comply with emissions regulations and can lead to fines or failed emissions tests.
• Engine at operating temperature
• Vehicle in closed-loop mode
The EGR valve and sensor are typically located near the intake manifold on the engine.
Q: Can I drive my car with a P0406 code?
A: While you can drive the car, it's not recommended as it may lead to increased emissions and potential engine damage.
Q: How do I clear a P0406 code?
A: After repairing the issue, you can clear the code with an OBD-II scanner.
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