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Home/DTC Codes/Fiat/Uno/2010-2021 1.0L I4 Flex Fire Evo/P0128
P0128

Coolant Thermostat Below Regulating Temperature

2010-2021 Fiat Uno 1.0L I4 Flex Fire Evo

Low SeverityPowertrainGeneric (SAE)

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

  1. Monitor ECT warmup curve
  2. Check thermostat
  3. Verify fan operation
  4. Test ECT sensor

Repair Notes

Replace thermostat.

Related Codes

P0115Engine Coolant Temperature (ECT) Sensor 1 CircuitP0116ECT Sensor 1 Circuit Range/PerformanceP0125Insufficient Coolant Temperature for Closed Loop Fuel Control

Other Powertrain Codes

P0128 on Other Vehicles

Fiat 124 Spider

2017-2020 1.4L I4 Turbo

Fiat 126p Maluch

1973-2000 0.65L I2 Air-Cooled

Fiat 126p Maluch

1987-2000 0.7L I2 Air-Cooled

Fiat 500

2012-2019 1.4L I4

Fiat 500 Abarth

2012-2019 1.4L I4 Turbo

Fiat 500 BR

2011-2020 1.4L I4 Flex Fire Evo

Fiat 500 PL

2007-2025 1.0L I3 Hybrid FireFly 70

Fiat 500 PL

2007-2025 1.2L I4 Fire 69

Common Questions

What does code P0128 mean on a 2010-2021 Fiat Uno?

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 Fiat Uno?

Common symptoms of P0128 include: Check Engine Light, Poor fuel economy, Heater not getting hot, Engine running cool.

What causes P0128 on a 2010-2021 Fiat Uno?

Common causes of P0128 include: Stuck-open thermostat, Missing thermostat, Faulty ECT sensor, Cooling fan stuck on.

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