P0126moderate severityPowertrain
Insufficient Coolant Temperature for Stable Operation
on 2015 Kia Forte 1.8L I4 · FWD
What this code means
The engine is not reaching or holding a stable operating temperature. This is often caused by a thermostat stuck open.
Symptoms
- Poor heater output
- Poor fuel economy
- Longer warm-up time
Common causes
- Thermostat stuck open
- Faulty engine coolant temperature sensor
- Low coolant level
- Faulty cooling fan running constantly
Diagnostic steps
- Monitor coolant temperature at warm-up
- Inspect thermostat operation
- Test coolant temperature sensor
- Replace thermostat or sensor as needed
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Other Powertrain codes on this vehicle
P0001
Fuel Volume Regulator Control Circuit/Open
P0002
Fuel Volume Regulator Control Circuit Range/Performance
P0003
Fuel Volume Regulator Control Circuit Low
P0004
Fuel Volume Regulator Control Circuit High
P0005
Fuel Shutoff Valve A Control Circuit/Open
P0006
Fuel Shutoff Valve A Control Circuit Low
P0007
Fuel Shutoff Valve A Control Circuit High
P0008
Engine Position System Performance - Bank 1
P0009
Engine Position System Performance - Bank 2
P0010
Intake Camshaft Position Actuator Circuit/Open Bank 1