OBD · Cooling
P0128 Coolant temperature below thermostat regulating temperature
What this code means
P0128 is a generic OBD code shared by all manufacturers since 2001 for petrol and 2004 for diesel. It relates to: cooling. The code tells you what the ECU measured as abnormal, not necessarily which part to replace.
Most common causes
- Stuck thermostat#1
Cost of related repairs
| Independent garage | Main dealer | |
|---|---|---|
| Thermostat | £80 – £280 | £115 – £470 |
How to read this code
An OBD scanner plugged into the 16-pin socket under the steering wheel reads and clears codes. Bluetooth models cost £20 to £40. Clearing a code without fixing the fault is pointless: it comes back.
Related problems
Frequently asked questions
What does code P0128 mean?
P0128: Coolant temperature below thermostat regulating temperature. P0128 is a generic OBD code shared by all manufacturers since 2001 for petrol and 2004 for diesel. It relates to: cooling. The code tells you what the ECU measured as abnormal, not necessarily which part to replace.
Can I drive with code P0128?
Monitor. You can drive normally but get it checked in the coming weeks. It may fail an MOT or roadworthiness test.
How much does it cost to fix P0128?
Thermostat: £80 – £280.
How to read this code
An OBD scanner plugged into the 16-pin socket under the steering wheel reads and clears codes. Bluetooth models cost £20 to £40. Clearing a code without fixing the fault is pointless: it comes back.