Engine Coolant Temperature Sensor 2 Circuit High
The P2185 code indicates that the Engine Control Module (ECM) has detected a voltage signal from the Engine Coolant Temperature (ECT) Sensor 2 that is higher than the expected range. This typically means the sensor is reading an abnormally low temperature (high resistance) or there is an open circuit. ECT Sensor 2 is often located on the engine block or cylinder head, separate from the main ECT sensor. High voltage can be caused by a faulty sensor, wiring issues, or a poor connection.
1. Most Common Causes
- Faulty Engine Coolant Temperature Sensor 2
- Open or shorted wiring in the sensor circuit
- Poor electrical connection at the sensor or ECM
- Corroded or damaged connector pins
- ECM failure (rare)
2. Symptoms You Will Notice
- Check Engine Light illuminated
- Engine may run rich or lean, causing poor fuel economy
- Hard starting, especially when cold
- Cooling fan may run continuously or not at all
- Engine may overheat or run cooler than normal
3. Step-by-Step Diagnosis
Step 1: Scan the vehicle for codes and record freeze frame data.
Step 2: Visually inspect the ECT sensor 2 connector and wiring for damage, corrosion, or loose connections.
Step 3: Disconnect the sensor and measure resistance across its terminals; compare to manufacturer specifications (typically 2-10 kΩ at cold engine).
Step 4: Check voltage at the sensor connector with the ignition on; should be around 5V reference signal. If not, check wiring to ECM.
Step 5: If sensor and wiring are good, test the ECM output by backprobing the signal wire; if voltage is still high, replace the sensor.
4. Frequently Asked Questions
Is it safe to drive with this code?▼
It is not recommended to drive long distances with this code, as incorrect coolant temperature readings can cause poor engine performance, reduced fuel economy, and potential overheating or engine damage. It's best to diagnose and repair promptly.
How much does it cost to fix?▼
The cost to fix P2185 typically ranges from $50 to $150, including parts and labor. The sensor itself costs $20-$50, and labor is usually 0.5-1 hour. Additional costs may apply if wiring repairs are needed.
5. Commonly Affected Makes
This is a generic OBD2 code, potentially applicable to any manufacturer using this diagnostic standard.