P0127 Buick Intake Air Temperature Too High

P0128 Buick Engine Coolant Temperature Below Thermostat Regulating Temperature

Possible causes
– Leaking or stuck open thermostat
– Low engine coolant level
– Insufficient warm up time
– Faulty engine coolant temperature sensor
– Engine coolant temperature sensor harness is open or shorted
– Engine coolant temperature sensor circuit poor electrical connection
Tech description
If cooling system is not leaking and the fluid level is OK, replacing the thermostat usually takes care of the problem.
What about the obd code?
If the Powertrain Control Module (PCM) detects the calibrated amount of air flow and engine run time have been met, and the Engine Coolant Temperature (ECT) has not met the minimum thermostat regulating temperature, the code P0128 Buick will set.
Symptoms
– Engine Light ON (or Service Engine Soon Warning Light)
P0128 Buick Description

An Engine Coolant Temperature (ECT) sensor monitors the temperature of the coolant. This input is used by the Powertrain Control Module (PCM) for engine control and as an enabling criteria for some diagnosis.

The air flow coming into the engine is accumulated and used to determine if the vehicle has been driven within the conditions that would allow the engine coolant to heat up normally to the thermostat regulating temperature. If the coolant temperature does not increase normally or does not reach the regulating temperature of the thermostat, the diagnostic that use ECT as enabling criteria may not run when expected.

Buick Vehicle:Buick Regal – ?Buick Riviera – ?Buick LaCrosse – ?David Dunbar Buick – Buick Century – Buick LaCrosse – Buick LeSabre – Buick Lucerne – Buick Park Avenue – Buick Regal – Buick Verano – Buick Enclave – Buick Encore – Buick Rainier – Buick Rendezvous – Buick Terraza – Buick Riviera