• Check Engine Light is on
• Poor engine performance
• Increased emissions
• Faulty exhaust pressure sensor
• Wiring issues such as damaged wires or poor connections
• Faulty ECM
ECM: Engine Control Module
OBD-II: On-Board Diagnostics II
• P0470
• P0471
• P0472
Exhaust Pressure Sensor A Circuit Intermittent/Erratic
This code means that the car's computer is having trouble getting a clear signal from a sensor that measures the pressure in the exhaust system. It's like trying to listen to a radio station that keeps cutting in and out.
The exhaust pressure sensor measures the pressure in the exhaust system and sends this information to the engine control module (ECM). An intermittent or erratic signal can cause the ECM to misinterpret the exhaust pressure.
The P0474 code is triggered when the ECM detects an intermittent or erratic signal from the exhaust pressure sensor 'A'. This sensor is responsible for monitoring the pressure in the exhaust system, which helps in optimizing engine performance and emissions. An erratic signal can lead to incorrect adjustments by the ECM.
• Use an OBD-II scanner to verify the code.
• Inspect the exhaust pressure sensor and its wiring for damage.
• Test the sensor's output with a multimeter.
• Replace the faulty exhaust pressure sensor.
• Repair or replace damaged wiring or connectors.
• Reprogram or replace the ECM if necessary.
• OBD-II scanner
• Multimeter
• Basic hand tools
$100 - $300
Moderate
• Ford F-Series
• Chevrolet Silverado
• Dodge Ram
• Regularly inspect and maintain exhaust system components.
• Ensure all electrical connections are secure and free of corrosion.
• Use quality fuel to prevent sensor contamination.
Sensor Issue
• Have the vehicle inspected by a professional mechanic.
• Do not ignore the Check Engine Light as it may lead to further issues.
• Regular maintenance can prevent such issues.
Check with the vehicle manufacturer for warranty coverage on emissions-related components.
This code has been more common in vehicles with higher mileage or those that frequently operate under heavy load conditions.
Moderate – While the vehicle may still be drivable, it is recommended to address the issue soon to avoid potential engine performance problems.
Driving with a malfunctioning exhaust pressure sensor may lead to increased emissions, which can be illegal in some regions.
• Engine at operating temperature
• Vehicle in a safe and secure location
The exhaust pressure sensor is typically located near the exhaust manifold or turbocharger.
Q: Can I drive with a P0474 code?
A: It's possible to drive with this code, but it's best to have it checked soon to avoid potential engine performance issues.
Q: How does an exhaust pressure sensor work?
A: It measures the pressure in the exhaust system and sends this information to the ECM to help control engine performance and emissions.