Will a P0128 Code Clear Itself?
Can a P0128 Code Go Away on Its Own?
Yes, the P0128 code (Coolant Temperature Below Thermostat Regulating Temperature) can clear itself, but only if the issue is temporary and the engine eventually reaches proper operating temperature. However, if the thermostat or coolant sensor is faulty, the code will stay active until the problem is fixed.
What Causes a P0128 Code?
How Long Does It Take for P0128 to Clear?
- If the issue was temporary (e.g., cold weather or low coolant, and it’s corrected), the code may clear itself after several drive cycles (50–100 miles).
- If the problem is mechanical (stuck thermostat, bad sensor), the code will stay on until the faulty part is replaced.
How to Manually Clear a P0128 Code
✅ Use an OBD-II Scanner – Scan and reset the code, but if the issue isn’t fixed, the light will return.
✅ Fix the Underlying Issue – If the thermostat or sensor is faulty, replace it to prevent the code from coming back.
✅ Drive Normally – If the problem was minor, the ECU may turn off the check engine light after a few drive cycles.
Final Thoughts
The P0128 code may clear itself if the engine eventually reaches normal temperature. However, if the thermostat, coolant sensor, or cooling system has a real issue, the code will stay on until repaired. If the check engine light persists, diagnose and fix the root cause to prevent further problems.
FAQs
1. Can I drive with a P0128 code?
Yes, but the engine running too cool can reduce fuel efficiency and increase emissions.
2. How do I know if my thermostat is bad?
- The engine takes too long to warm up.
- The heater blows lukewarm air instead of hot air.
- The temperature gauge stays low.
3. How much does it cost to fix a P0128 code?
- New thermostat: $20–$100 for the part, $150–$300 with labor.
- Coolant temperature sensor: $20–$50 for the part, $100–$250 with labor.
4. How many drive cycles to clear P0128?
If the problem is fixed, 3–5 drive cycles (50–100 miles) may clear the code.
5. Will flushing the coolant fix P0128?
Only if the issue was low or dirty coolant—a bad thermostat or sensor will still need to be replaced.
Also Check:
• Does a Throttle Body Need to Be Programmed?
• Will the Check Engine Light Turn Off on Its Own?
• Does ToyotaCare Cover Check Engine Light Diagnosis?
