DTC P0128
The engine coolant temperature is not reaching the proper operating temperature within a specified time.
Diagnostic summary
P0128
What it means
The engine coolant temperature is not reaching the proper operating temperature within a specified time.
Can you drive?
🔍 Needs diagnosis
Urgency
Medium 5/10
Typical price
$50 – $500
Check first
Thermostat stuck open
Based on real scans · 1 Updated May 7, 2026 Seen on Powertrain
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ℹ️ What does it mean?
The engine coolant temperature is not reaching the proper operating temperature within a specified time.
⚠️ Possible Causes
- ⚠ Thermostat stuck open
- ⚠ Faulty coolant temperature sensor
- ⚠ Low coolant level
🚗 Can I drive with this code?
Needs diagnosis
Depends on symptoms. We recommend running a diagnostic scan before driving.
🛠️ How to Fix
- 1 Replace thermostat
- 2 Replace coolant temperature sensor
- 3 Add coolant to the system
💰 Estimated Repair Cost
Repair cost by car / region
Early rough estimate. Accuracy improves as more real repair stories are added.
DIY / parts$18 – $325
Mechanic / labor$23 – $375
Repair range$50 – $500
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Scanned 1 times in the app
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