P21AF Chevrolet Code - Reductant Level Sensor 3 Circuit Low Voltage
Quick Answer
The reductant level/temperature sensor is a solid-state device that provides the Engine Control Module (ECM) with information on reductant level and temperature. Common causes include Faulty Reductant Level Sensor 3, Reductant Level Sensor 3 harness is open or shorted, Reductant Level Sensor 3 circuit poor electrical connection. Severity is High - diagnose this code as soon as possible. Driving is not recommended if the warning light is flashing, the engine runs poorly, or safety-related symptoms are present.
- What it means
- P21AF Chevrolet indicates Reductant Level Sensor 3 Circuit Low Voltage.
- Common causes
- Common causes include Faulty Reductant Level Sensor 3, Reductant Level Sensor 3 harness is open or shorted, Reductant Level Sensor 3 circuit poor electrical connection.
- Severity
- High - diagnose this code as soon as possible.
- Can I drive?
- Driving is not recommended if the warning light is flashing, the engine runs poorly, or safety-related symptoms are present.
Code P21AF Chevrolet Description
What are the Possible Causes of the DTC P21AF Chevrolet?
- Faulty Reductant Level Sensor 3
- Reductant Level Sensor 3 harness is open or shorted
- Reductant Level Sensor 3 circuit poor electrical connection
How to Fix the DTC P21AF Chevrolet?
Review the 'Possible Causes' above and visually examine the corresponding wiring harness and connectors. Check for damaged components and inspect connector pins for signs of being broken, bent, pushed out, or corroded.
What is the Cost to Diagnose the Code?
Labor: 1.0
To diagnose the P21AF Chevrolet code, it typically requires 1.0 hour of labor. Rates vary by location, vehicle, and shop. Many shops charge between $80–$150 per hour; dealerships and metro areas may be higher, independents may be lower.
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Frequently Asked Questions about P21AF Chevrolet Code
1. What does OBDII code P21AF mean on a Chevrolet?
P21AF indicates a "Reductant Level Sensor 3 Circuit Low Voltage," meaning the vehicle's diesel exhaust fluid (DEF) system is detecting an issue with the voltage signal from the third reductant level sensor.
2. What are the symptoms of code P21AF in a Chevrolet?
Common symptoms include a check engine light, DEF system warnings, reduced engine performance, or a "limp mode" condition if the issue is not resolved.
3. What causes the P21AF code to appear?
The most common causes are a faulty reductant level sensor, damaged wiring, poor electrical connections in the sensor circuit, or a failed DEF tank module.
4. Can I drive with the P21AF code active?
While the vehicle may still be drivable, prolonged driving with this code can lead to reduced performance or force the vehicle into limp mode. It's best to address the issue promptly.
5. How is the P21AF code diagnosed?
A mechanic will typically use a scan tool to confirm the code, inspect the wiring and connectors for damage, and test the sensor circuit and DEF tank module for proper function.
6. What repairs are commonly needed for the P21AF code?
Repairs may include replacing the reductant level sensor, repairing damaged wiring, cleaning corroded connections, or replacing the DEF tank module if it's defective.
7. How much does it cost to fix a P21AF code on a Chevrolet?
The repair cost can vary but typically ranges from $200 to $600, depending on whether the sensor, wiring, or DEF tank module needs replacement.
8. Can a P21AF code be caused by low DEF fluid?
No, this code specifically relates to the sensor circuit's low voltage, not the DEF fluid level. However, a low DEF level may trigger separate warnings.
9. How can I prevent the P21AF code from recurring?
Regularly inspect and maintain the DEF system, ensure proper connections, and avoid contamination or damage to the DEF tank and sensors.
10. Will clearing the P21AF code fix the problem?
Clearing the code may temporarily turn off the check engine light, but the underlying issue must be resolved to prevent the code from returning.
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