P23B4 — NOx Sensor Heater Sense Circuit Bank 1 Sensor 3

What Does P23B4 Mean?

P23B4 is a diagnostic trouble code indicating: NOx Sensor Heater Sense Circuit Bank 1 Sensor 3. This code relates to the powertrain system. The vehicle's computer detected a condition outside normal operating parameters and stored this code.

Symptoms of P23B4

⚠️ Check Engine Light (MIL) illuminated
⚠️ Erratic NOx Sensor Heater Sense readings
⚠️ Related system operating intermittently
⚠️ Reduced engine performance

Common Causes

🔍 Wiring issue in NOx Sensor Heater Sense circuit (damaged, chafed, or corroded)
🔍 Faulty NOx Sensor Heater Sense connector or terminal
🔍 Failed NOx Sensor Heater Sense
🔍 ECM/PCM connection issue

Frequently Asked Questions

What does P23B4 mean?

P23B4 indicates: NOx Sensor Heater Sense Circuit Bank 1 Sensor 3. The vehicle's computer has detected that the NOx Sensor Heater Sense is not operating within its expected parameters and stored this diagnostic trouble code.

Can I drive with code P23B4?

You can drive short distances for essential trips, but schedule a diagnosis soon. Driving with P23B4 for extended periods may cause additional problems.

How much does it cost to fix P23B4?

Repair costs for P23B4 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 and repair NOx Sensor Heater Sense wiring and connectors
🔧 Replace faulty NOx Sensor Heater Sense

1
Find your vehicle above
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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.

P23B4: NOx Sensor Heater Sense Circuit Bank 1 Sensor 3