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 reading the sensor that measures the pressure of a special fluid used to clean the exhaust. The readings are not steady, like when a TV signal keeps cutting out.
The P204E code indicates that the signal from the reductant pressure sensor is not consistent, which means the sensor might be malfunctioning or there could be a wiring issue.
The reductant pressure sensor monitors the pressure of the diesel exhaust fluid (DEF) in the system. An intermittent or erratic signal suggests that the sensor is not providing a stable output, which could be due to electrical issues or sensor failure.
• Check Engine Light is on
• Possible reduction in engine performance
• Increased emissions
• Faulty reductant pressure sensor
• Wiring issues or poor connections
• Faulty powertrain control module (PCM)
Reductant: A fluid used to reduce emissions in diesel engines.
DEF: Diesel Exhaust Fluid, a liquid used in the selective catalytic reduction system to reduce emissions.
• Use an OBD-II scanner to confirm the code.
• Inspect wiring and connections to the reductant pressure sensor.
• Test the sensor for proper operation using a multimeter.
• Repair or replace any damaged wiring or connectors.
• Replace the reductant pressure sensor if faulty.
• Reprogram or replace the PCM if necessary.
• OBD-II scanner
• Multimeter
• Basic hand tools
$150 - $400
Moderate
• Ford F-Series
• Chevrolet Silverado
• Ram 1500
• Regular maintenance of the exhaust system
• Ensure proper DEF levels
• Inspect wiring regularly
Sensor Issue
• Address the issue promptly to avoid further damage.
• Consult a professional mechanic if unsure.
Check vehicle warranty for coverage on emissions-related components.
This code has become more common with the increased use of DEF systems in diesel vehicles.
Moderate – Should be addressed soon to prevent emissions issues.
Driving with this code may result in higher emissions, which could be against local regulations.
• Engine running
• Vehicle at operating temperature
The reductant pressure sensor is typically located near the DEF tank or along the DEF line.
Q: Can I drive with a P204E code?
A: It's possible to drive short distances, but it's best to fix the issue soon to avoid emissions problems.
Q: What happens if I ignore this code?
A: Ignoring the code can lead to increased emissions and possible engine performance issues.
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