P21C6 — Reductant Level Sensor B Stuck

What Does P21C6 Mean?

P21C6 is a diagnostic trouble code indicating: Reductant Level Sensor B Stuck. This code relates to the powertrain system. The vehicle's computer detected a condition outside normal operating parameters and stored this code.

Symptoms of P21C6

⚠️ Check Engine Light (MIL) illuminated
⚠️ Reductant Level Sensor B Stuck not functioning as expected
⚠️ Related system may be in fail-safe mode
⚠️ Reduced engine performance

Common Causes

🔍 Faulty Reductant Level Sensor B Stuck
🔍 Wiring or connector issue in Reductant Level Sensor B Stuck circuit
🔍 Related mechanical or electrical fault
🔍 ECM/PCM issue (rare)

Frequently Asked Questions

What does P21C6 mean?

P21C6 indicates: Reductant Level Sensor B Stuck. The vehicle's computer has detected that the Reductant Level Sensor B Stuck is not operating within its expected parameters and stored this diagnostic trouble code.

Can I drive with code P21C6?

You can drive short distances for essential trips, but schedule a diagnosis soon. Driving with P21C6 for extended periods may cause additional problems.

How much does it cost to fix P21C6?

Repair costs for P21C6 typically range from $80 to $300, depending on the root cause. Simple wiring or connector repairs are on the lower end, while component replacement costs more. A proper diagnosis ($80–$150 at most shops) will identify the exact cause before committing to expensive parts.

What To Do Next

Possible Fixes

🔧 Inspect Reductant Level Sensor B Stuck and related wiring
🔧 Replace faulty Reductant Level Sensor B Stuck

1
Find your vehicle above
Click your make and model for real owner reports and common causes specific to your vehicle.
2
Check for recalls
Go to nhtsa.gov/recalls and enter your VIN. Free repairs if covered.
3
Get a professional diagnosis
A code alone doesn't identify the exact failed part. A diagnostic ($50–$150) pinpoints the root cause.

P21C6: Reductant Level Sensor B Stuck