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 is having trouble figuring out the pressure of the air used to help clean the exhaust. It's like when you can't tell if a balloon is full or not because the sensors are confused.
The vehicle's engine control module (ECM) detects a mismatch between the readings of two air pressure sensors used in the reductant injection system.
The P209E code is triggered when the ECM detects a correlation issue between the Reductant Injection Air Pressure Sensor A and Sensor B. These sensors are part of the selective catalytic reduction (SCR) system, which reduces emissions by injecting a reductant (usually urea) into the exhaust stream. The sensors help ensure the correct amount of reductant is used by monitoring the air pressure required for injection.
• Check Engine Light is on
• Possible decrease in fuel efficiency
• Potential increase in exhaust emissions
• Faulty air pressure sensor A or B
• Wiring issues or poor connections
• Faulty ECM
ECM: Engine Control Module
SCR: Selective Catalytic Reduction
• Use an OBD-II scanner to confirm the code.
• Inspect the wiring and connections to the sensors.
• Test the sensors for proper operation.
• Replace faulty air pressure sensor A or B.
• Repair or replace damaged wiring or connectors.
• Reprogram or replace the ECM if necessary.
• OBD-II scanner
• Multimeter
• Basic hand tools
$150 - $500
Moderate
• Ford F-250
• Chevrolet Silverado
• Ram 2500
• Regular maintenance and inspection of the SCR system.
• Ensure proper installation of sensors.
• Use high-quality reductant fluid.
Sensor Issue
• Have the vehicle inspected by a professional if the Check Engine Light is on.
• Avoid ignoring the issue as it may lead to increased emissions.
Check with the vehicle manufacturer for warranty coverage on emissions-related components.
This code has become more common with the introduction of stricter emissions standards and the widespread use of SCR systems.
Moderate – Should be addressed to prevent increased emissions and potential damage to the SCR system.
Driving with this code may lead to failing emissions tests and is not environmentally friendly.
• Vehicle at operating temperature
• Engine running at idle
The air pressure sensors are typically located near the SCR system, which is part of the exhaust system.
Q: Can I drive with a P209E code?
A: It's possible to drive, but it's not recommended as it may lead to increased emissions and potential damage to the SCR system.
Q: How do I clear a P209E code?
A: Fix the underlying issue and use an OBD-II scanner to clear the code. If the problem persists, the code will return.
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