P0128low severityPowertrain
Coolant Thermostat Below Regulating Temperature
on 2024 Chevrolet Equinox EV Electric Dual Motor AWD ยท AWD
What this code means
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.
๐ Don't have a code reader?
Any of these will read and clear this code โ pick by how deep you want to go.
Budget handheld~$40
ANCEL AD410 โ
No-phone-needed handheld โ reads, clears, live data, freeze frame.
โ ANCEL official store
Serious DIY~$100
BlueDriver Pro โ
Enhanced codes (ABS, airbag, TPMS) plus repair reports.
SHOP FAVORITEShop-grade tablet~$300
Autel MaxiCOM MK808S โ
Bidirectional tests, service resets, all systems.
โ Autel official store
Pro diagnostics$1,500+
Autel MaxiSys MS906 Pro โ
Full-system pro platform โ topology mapping, ECU coding, the works.
โ Autel official store
As an Amazon Associate and Autel/ANCEL partner, OLP earns from qualifying purchases โ how we link. This never changes the specs we publish.
Other Powertrain codes on this vehicle
P0070
Ambient Air Temperature Sensor Circuit
P0071
Ambient Air Temperature Sensor Range/Performance
P0072
Ambient Air Temperature Sensor Circuit Low
P0073
Ambient Air Temperature Sensor Circuit High
P0115
Engine Coolant Temperature (ECT) Sensor 1 Circuit
P0116
ECT Sensor 1 Circuit Range/Performance
P0117
ECT Sensor 1 Circuit Low Input
P0118
ECT Sensor 1 Circuit High Input
P0119
ECT Sensor 1 Circuit Intermittent
P0125
Insufficient Coolant Temperature for Closed Loop Fuel Control