Radiator Coolant Temp Sensor Circuit Intermittent
The P00B5 code indicates an intermittent or erratic signal from the radiator coolant temperature sensor circuit. This sensor monitors coolant temperature exiting the radiator and helps the PCM control cooling fans and engine temperature. An intermittent fault may be caused by loose connections, damaged wiring, or a failing sensor, leading to unreliable temperature readings.
01. Most Common Causes
- Faulty radiator coolant temperature sensor
- Damaged or corroded wiring/connectors in the sensor circuit
- Intermittent short or open in the circuit
- Poor electrical connection at the sensor or PCM
02. Symptoms You Will Notice
- Check Engine Light illuminated
- Engine overheating or running cooler than normal
- Cooling fans running erratically or not at all
- Poor fuel economy or engine performance issues
03. Step-by-Step Diagnosis
Step 1: Scan for codes and record freeze frame data to capture conditions when the fault occurred.
Step 2: Visually inspect the radiator coolant temperature sensor connector and wiring for damage, corrosion, or loose connections.
Step 3: Use a multimeter to check sensor resistance at different temperatures and compare to manufacturer specs.
Step 4: Monitor sensor signal with a scan tool while wiggling the wiring harness to reproduce the intermittent fault.
Step 5: If wiring and sensor check out, test the PCM for proper signal processing or check for aftermarket modifications.
04. Commonly Affected Makes
05. Frequently Asked Questions
Is it safe to drive with this code?▼
It is not recommended to drive with this code as it can lead to engine overheating or cooling system malfunction, potentially causing serious engine damage.
How much does it cost to fix?▼
The typical repair cost ranges from $50 to $150, including parts (sensor $20-$60) and labor, depending on the cause and vehicle model.