What is the P0128 engine fault codes? How can you fix P0128 fault code What are the causes and symptoms of P0128 fault code How to fix Coolant Thermostat Failure ?….
P0128, “Coolant Temperature Malfunction”, is a condition in which the coolant does NOT reach its normal temperature after the engine has started. The PCM calculates the time by measuring vehicle’s running times and rpm using the Intake Air Temperature Sensors (IAT) and Engine Coolant Temperature Sensors (ECT). The Engine Check Lamp will be on, but you won’t feel any driving problems.
Causes of Fault Code P0128
- The most common cause of a thermostat that is not properly closed or sealed is a leaky, stuck-open, or prematurely open thermostat.
- – Problems with wiring or the engine coolant temperature sensor (ECT).
- Low coolant level
- – Bad cooling fan (works too hard, won’t turn on)
- – Wiring problems or defective intake air temperature sensor (IAT).
What are the symptoms of P0128 Fault code?
- – Engine Malfunction Lamp illuminates
- – It takes longer for your engine to warm up in colder temperatures
- – High speeds can cause the engine temperature to drop.
- – Heaters do not blow hot air
How can P0128 fault be diagnosed?
There may be a variation in diagnostic methods from master to master. First, check the temperature of coolant in the radiator hose that is connected to the thermostat. When the thermostat opens, the hose should be warmed up. Once the thermostat is turned on the hose will heat quickly and hot water will start flowing. Be careful not to burn yourself.
The thermostat may be left open if the hose heats slowly or is not heating up. The temperature sensor will tell you if the hose is heating up correctly. A diagnostic device is required to check this. Temperature should not exceed 200 degrees Fahrenheit. This value should be compared using an infrared thermometer. If these values are not consistent, the sensor may be defective. The sockets and sensor cables should be checked in this instance. If there are no problems with the sockets or cables, the sensor may be defective and should be replaced.
Rarely, the problem may be with the engine control module’s supply voltage. Reprogramming the PCM with the most recent software might resolve the problem if no errors are found.
Common Mistakes when diagnosing code P0128
Nine out of ten mechanics will tell you the thermostat problem is P0128. Although the vast majority of people will be correct, it’s sometimes impossible to fix the problem by simply changing the thermostat.
What’s the significance of the P0128 fault code?
P0128 does not cause any significant damage to your vehicle. It is possible for the oil to contaminate with water and cause engine damage if the problem isn’t addressed immediately. It can take approximately one year for engine damage symptoms to develop. We recommend that you get to the source of the problem quickly.
The P0128 fault code is also common during winter months. Extreme temperatures in summer help the vehicle heat up normally. In cold weather, however, the engine will not warm up as quickly.
