Jan 7, 2023 · If your car has been displaying the P0128 code, don't panic! This article will walk you through everything you need to know about this code.

When your check engine light is illuminated due to trouble code P0128, you may have an issue with your engine thermostat. Here are some helpful steps to take to find out how do I fix trouble code P0128?

This guide explains the P0128 code’s meaning, symptoms, causes, and step-by-step diagnostics to fix it like a pro—potentially saving you $300-$600 from overpriced cooling system repairs.

Sep 7, 2024 · What can cause the OBDII code P0128 in a Chevrolet? - The code P0128 in a Chevrolet is often caused by a malfunctioning thermostat, low coolant levels, a faulty coolant temperature …

Jul 31, 2021 · In some GM cars when the code P0128 is set, the temperature gauge stops working and the radiator fans run constantly. Replacing the thermostat often solves the problem unless there are …

May 8, 2025 · Low coolant levels, a stuck engine coolant thermostat, and issues with the coolant temperature sensor or its wiring can cause code P0128. Symptoms of the P0128 code include an …

Jan 6, 2026 · Decode P0128 and resolve engine running too cool. Full guide to diagnosing thermostat failure, sensor issues, and step-by-step repair instructions.

Sep 12, 2024 · The P0128 error code on your car is officially known as "Coolant Thermostat (Coolant Temperature Below Thermostat Regulating Temperature)." We tell you what it means and what to do.

Your engine needs to operate at normal operating temperature for optimum performance. When the PCM observes that the coolant temperature is lower than the temperature set by the thermostat, it …

Coolant Thermostat (Coolant Temperature Below Thermostat Regulating Temperature) What does that mean? This diagnostic trouble code (DTC) is a generic powertrain code, which means that it applies …