Coolant Thermostat Below Regulating Temperature
2013-2021 Peugeot 308 1.2L I3 PureTech 🇩🇪
Description
The engine coolant has not reached the expected temperature within a specified time after startup.
Symptoms
- Check Engine Light
- Poor fuel economy
- Heater not getting hot
- Engine running cool
Common Causes
- Stuck-open thermostat
- Missing thermostat
- Faulty ECT sensor
- Cooling fan stuck on
Diagnostic Steps
- Monitor ECT warmup curve
- Check thermostat
- Verify fan operation
- Test ECT sensor
Repair Notes
Replace thermostat.
Related Codes
Other Powertrain Codes
- P0001Fuel Volume Regulator Control Circuit/Open
- P0002Fuel Volume Regulator Control Circuit Range/Performance
- P0003Fuel Volume Regulator Control Circuit Low
- P0004Fuel Volume Regulator Control Circuit High
- P0010Intake Camshaft Position Actuator Circuit/Open Bank 1
- P0011Intake Camshaft Position Timing Over-Advanced Bank 1
- P0012Intake Camshaft Position Timing Over-Retarded Bank 1
- P0013Exhaust Camshaft Position Actuator Circuit/Open Bank 1
- P0014Exhaust Camshaft Position Timing Over-Advanced Bank 1
- P0015Exhaust Camshaft Position Timing Over-Retarded Bank 1
P0128 on Other Vehicles
Peugeot 108
2014-2021 1.0L I3 VTi 72
Peugeot 108
2014-2021 1.2L I3 PureTech 82
Peugeot 2008
2019-2024 1.2L I3 PureTech
Peugeot 2008
2019-2024 Electric
Peugeot 2008
2019-2025 1.2L I3 Turbo PureTech 130
Peugeot 2008
2020-2025 Electric e-2008 50kWh
Peugeot 2008 PL
2019-2025 1.2L I3 Turbo PureTech 130
Peugeot 2008 PL
2019-2025 1.5L I4 Diesel BlueHDi 110
Common Questions
What does code P0128 mean on a 2013-2021 Peugeot 308?
P0128 stands for "Coolant Thermostat Below Regulating Temperature". The engine coolant has not reached the expected temperature within a specified time after startup.
What are the symptoms of P0128 on a Peugeot 308?
Common symptoms of P0128 include: Check Engine Light, Poor fuel economy, Heater not getting hot, Engine running cool.
What causes P0128 on a 2013-2021 Peugeot 308?
Common causes of P0128 include: Stuck-open thermostat, Missing thermostat, Faulty ECT sensor, Cooling fan stuck on.