P00B4 — Radiator Coolant Temperature Sensor Circuit High

What Does P00B4 Mean?

P00B4 is a diagnostic trouble code indicating: Radiator Coolant Temperature Sensor Circuit High. This code relates to the fuel and air metering system. The vehicle's computer detected a condition outside normal operating parameters and stored this code.

Symptoms of P00B4

⚠️ Check Engine Light (MIL) illuminated
⚠️ Radiator Coolant Temperature Sensor reading stuck at maximum value
⚠️ Related system operating erratically or in default mode
⚠️ Poor fuel economy

Common Causes

🔍 Short to voltage in Radiator Coolant Temperature Sensor wiring harness
🔍 Corroded or water-damaged Radiator Coolant Temperature Sensor connector
🔍 Faulty Radiator Coolant Temperature Sensor outputting maximum voltage
🔍 Damaged wiring rubbing against metal components
🔍 ECM/PCM internal fault (rare)

Frequently Asked Questions

What does P00B4 mean?

P00B4 indicates: Radiator Coolant Temperature Sensor Circuit High. The vehicle's computer has detected that the Radiator Coolant Temperature Sensor is not operating within its expected parameters and stored this diagnostic trouble code.

Can I drive with code P00B4?

You can drive short distances for essential trips, but schedule a diagnosis soon. Driving with P00B4 for extended periods may cause additional problems.

How much does it cost to fix P00B4?

Repair costs for P00B4 typically range from $20 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 Radiator Coolant Temperature Sensor wiring for short to voltage
🔧 Clean or replace corroded Radiator Coolant Temperature Sensor connector
🔧 Replace faulty Radiator Coolant Temperature Sensor

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.

P00B4: Radiator Coolant Temperature Sensor Circuit High