Easy one-page printout for the garage or repair shop
This summary uses the existing diagnostic information shown in full below.
This code means there's a problem with the sensor that checks ammonia levels in the car's exhaust. It's like a nose that can't smell properly.
The P24E3 code indicates that the ammonia (NH3) sensor circuit is reading lower than expected values, suggesting a potential issue with the sensor or its circuit.
The NH3 sensor is part of the vehicle's emissions control system, monitoring ammonia levels to ensure proper functioning of the catalytic converter and SCR (Selective Catalytic Reduction) system. A 'circuit low' code suggests that the sensor is reporting a voltage or signal lower than the predefined threshold, which could be due to a faulty sensor, wiring issues, or a problem with the control module.
• Check Engine Light is on
• Possible decrease in fuel efficiency
• Increased emissions
• Faulty NH3 sensor
• Damaged or corroded wiring/connectors
• Malfunctioning control module
NH3: Ammonia, a compound used in emissions control systems.
SCR: Selective Catalytic Reduction, a system that reduces emissions using a catalyst.
• Use an OBD-II scanner to confirm the code.
• Inspect the NH3 sensor and its wiring for damage.
• Test the sensor's voltage and signal output.
• Replace the NH3 sensor if faulty.
• Repair or replace damaged wiring/connectors.
• Reprogram or replace the control module if necessary.
• OBD-II scanner
• Multimeter
• Basic hand tools
$200 - $600
Moderate
• Toyota Prius
• Ford F-250
• Chevrolet Silverado
• Regular maintenance checks
• Timely replacement of faulty sensors
• Keeping wiring and connectors clean and dry
Sensor Issue
• Have a professional diagnose the issue to avoid unnecessary repairs.
• Do not ignore the Check Engine Light as it may lead to further emissions issues.
Check if the vehicle's emissions system is under warranty, as this may cover sensor replacement.
This code has become more common with the increased use of SCR systems in modern vehicles to meet emissions standards.
Moderate – While not immediately critical, it should be addressed to ensure emissions compliance and avoid potential damage to the emissions system.
Driving with a malfunctioning emissions system may violate local emissions laws and contribute to air pollution.
• Engine at operating temperature
• Vehicle in closed-loop mode
The NH3 sensor is typically located in the exhaust system, downstream of the catalytic converter and SCR catalyst.
Q: Can I drive with the P24E3 code?
A: While you may be able to drive with this code, it's advisable to fix it soon to avoid emissions issues.
Q: What happens if I ignore the P24E3 code?
A: Ignoring this code can lead to increased emissions, potential fines, and damage to the emissions system.
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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.