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 has detected a problem with the sensor that measures ammonia levels in the exhaust. It's like when a thermometer isn't working right and gives a wrong temperature reading.
The NH3 sensor, or ammonia sensor, monitors the amount of ammonia in the vehicle's exhaust. This code indicates that the sensor is not operating within the expected range or performance parameters.
The P24E2 code is triggered when the Engine Control Module (ECM) detects that the NH3 sensor circuit is not performing as expected. This could be due to a malfunctioning sensor, wiring issues, or problems with the ECM itself. The NH3 sensor is crucial for monitoring the efficiency of the vehicle's Selective Catalytic Reduction (SCR) system, which reduces nitrogen oxide emissions.
• Check Engine Light illuminated
• Decreased fuel efficiency
• Increased emissions
• Possible reduction in engine performance
• Faulty NH3 sensor
• Wiring issues in the NH3 sensor circuit
• Defective ECM
• Contamination or blockage in the exhaust system
• Poor electrical connection
NH3 Sensor: A sensor that measures ammonia levels in the exhaust system.
SCR: Selective Catalytic Reduction, a system that reduces nitrogen oxide emissions.
• Use an OBD-II scanner to confirm the code.
• Inspect the NH3 sensor and its wiring for damage or disconnection.
• Test the NH3 sensor using a multimeter.
• Check the ECM for any additional fault codes.
• Replace the faulty NH3 sensor.
• Repair or replace damaged wiring or connectors.
• Clear the code and test drive the vehicle to ensure the issue is resolved.
• OBD-II scanner
• Multimeter
• Basic hand tools (screwdrivers, pliers)
$200 - $500
Moderate
• Ford F-150
• Chevrolet Silverado
• Ram 1500
• Regular maintenance and inspection of the exhaust system.
• Ensure the use of high-quality fuel.
• Keep the vehicle's software updated.
Sensor Issue
• Do not ignore the Check Engine Light.
• Have the vehicle inspected by a professional if you're unsure about repairs.
Check with your vehicle manufacturer for specific warranty coverage on emissions-related components.
The P24E2 code has become more common with the increased use of SCR systems in modern vehicles to meet stricter emissions standards.
Moderate – While the vehicle may still be drivable, it's important to address the issue to prevent increased emissions and potential damage to the SCR system.
Driving with a malfunctioning emissions system may violate emissions regulations and contribute to environmental pollution.
• Engine running at normal operating temperature
• Vehicle driven under various conditions to monitor sensor performance
The NH3 sensor is typically located in the exhaust system, downstream of the SCR catalyst.
Q: Can I drive with a P24E2 code?
A: While the vehicle may still operate, it's best to fix the issue to avoid increased emissions and potential damage to the emissions system.
Q: How often should the NH3 sensor be replaced?
A: The NH3 sensor should be inspected regularly and replaced as needed, typically during emissions-related maintenance.
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Universal · Digital multimeter
A solid entry-level multimeter for voltage, continuity, resistance, and basic electrical troubleshooting.
Helpful for checking voltage drops, grounds, and basic circuit health when modules are not communicating.
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Universal · Wire connectors and repair kit
Useful when diagnosis points toward damaged wiring, corroded terminals, or connector repairs.
Useful if diagnosis points toward damaged connectors, wiring, or terminal repairs.
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Fitment Required · Vehicle-fitment part
Relevant when catalyst-efficiency or emissions faults persist after proper diagnosis.
Catalyst-efficiency faults sometimes point toward converter problems after proper testing.
Catalytic converters are highly vehicle-specific and should not be purchased by code alone.
View options on AmazonThese parts may be related to this fault category, but a code by itself does not confirm exact fitment or guarantee that replacing a part will solve the problem.