Coolant Thermostat Below Regulating Temperature
2023-2023 Tesla Model 3 Standard Range Single Motor RWD
The 2023 Tesla Model 3 is equipped with a Standard Range Single Motor RWD engine (RWD). Below you'll find detailed p0128 diagnostic code information including labor time estimates, cost ranges, and technician notes specific to this engine configuration.
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
- P0070Ambient Air Temperature Sensor Circuit
- P0071Ambient Air Temperature Sensor Range/Performance
- P0072Ambient Air Temperature Sensor Circuit Low
- P0073Ambient Air Temperature Sensor Circuit High
- P0115Engine Coolant Temperature (ECT) Sensor 1 Circuit
- P0116ECT Sensor 1 Circuit Range/Performance
- P0117ECT Sensor 1 Circuit Low Input
- P0118ECT Sensor 1 Circuit High Input
- P0119ECT Sensor 1 Circuit Intermittent
- P0125Insufficient Coolant Temperature for Closed Loop Fuel Control
P0128 on Other Vehicles
Tesla Cybertruck
2024-2024 Cyberbeast Tri Motor AWD
Tesla Cybertruck
2024-2024 Dual Motor AWD
Tesla Cybertruck
2024-2024 Single Motor RWD
Tesla Model 3
2017-2017 Long Range Dual Motor AWD
Tesla Model 3
2017-2017 Performance Dual Motor AWD
Tesla Model 3
2017-2017 Standard Range Plus Single Motor RWD
Tesla Model 3
2018-2018 Long Range Dual Motor AWD
Tesla Model 3
2018-2018 Performance Dual Motor AWD
Common Questions
What does code P0128 mean on a 2023-2023 Tesla Model 3?
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 Tesla Model 3?
Common symptoms of P0128 include: Check Engine Light, Poor fuel economy, Heater not getting hot, Engine running cool.
What causes P0128 on a 2023-2023 Tesla Model 3?
Common causes of P0128 include: Stuck-open thermostat, Missing thermostat, Faulty ECT sensor, Cooling fan stuck on.
Last updated: March 2026