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 getting a steady signal from a sensor that checks for ammonia (NH3) in the exhaust. It's like when a TV signal keeps cutting in and out.
The P24E5 code is triggered when the Engine Control Module (ECM) detects an intermittent or erratic signal from the NH3 sensor circuit.
The NH3 sensor is responsible for monitoring the levels of ammonia in the vehicle's exhaust. This sensor helps ensure that the selective catalytic reduction (SCR) system is working correctly to reduce emissions. An intermittent or erratic signal can indicate issues with the sensor itself, the wiring, or the ECM.
• Check Engine Light illuminated
• Reduced fuel efficiency
• Failed emissions test
• Faulty NH3 sensor
• Damaged or corroded wiring/connectors
• Malfunctioning ECM
NH3: Ammonia, a compound of nitrogen and hydrogen.
SCR: Selective Catalytic Reduction, a system that reduces emissions from diesel engines.
• Use an OBD-II scanner to confirm the code.
• Inspect the NH3 sensor and wiring for damage.
• Test the sensor's output with a multimeter.
• Replace the NH3 sensor if faulty.
• Repair or replace damaged wiring/connectors.
• Reprogram or replace the ECM if necessary.
• OBD-II scanner
• Multimeter
• Socket set
$200 - $500
Moderate
• Vehicle 1
• Vehicle 2
• Vehicle 3
• Regularly inspect exhaust system components.
• Keep up with scheduled vehicle maintenance.
• Use quality fuel and additives.
Sensor Issue
• Have a professional inspect the vehicle if the Check Engine Light is on.
• Avoid ignoring the issue as it can affect emissions and performance.
Check with the vehicle manufacturer for warranty coverage on emissions-related components.
The P24E5 code has become more common with the increased use of SCR systems in modern vehicles to meet stringent emission standards.
Moderate – Addressing this issue promptly can prevent further emission-related problems.
Driving with a malfunctioning emissions system can lead to fines and environmental harm. Ensure repairs are made to comply with local emissions laws.
• Engine running at operating temperature
• Vehicle in closed-loop mode
The NH3 sensor is typically located in the exhaust system, near the SCR catalyst.
Q: Can I drive with a P24E5 code?
A: While you can drive with this code, it's best to address it soon to avoid emission issues.
Q: Will a P24E5 code affect performance?
A: It may affect fuel efficiency and emissions but not necessarily the overall performance immediately.
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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.