The P0128 error code on a Nissan Altima is related to the engine’s coolant temperature sensor. This code is triggered when the engine control module (ECM) detects that the engine is not reaching its proper operating temperature within a certain amount of time after starting.
Possible causes of a P0128 error code on a Nissan Altima include:
- A faulty engine coolant temperature sensor: This is the most common cause of the P0128 code. The sensor may be malfunctioning or sending incorrect data to the ECM.
- A stuck open thermostat: If the thermostat is stuck open, the engine may not reach its proper operating temperature, triggering the P0128 code.
- A low coolant level: If the coolant level is low, the engine may not be able to reach its proper operating temperature, triggering the P0128 code.
- A malfunctioning radiator fan: If the radiator fan is not functioning properly, it may prevent the engine from reaching its proper operating temperature.
- A faulty ECM: In rare cases, the engine control module may be malfunctioning and triggering the P0128 code incorrectly.
To diagnose and repair a P0128 error code on a Nissan Altima, it is recommended to take the car to a certified mechanic or Nissan dealership. They can use a diagnostic tool to read the error code and determine the exact cause of the problem. Repairs may involve replacing the engine coolant temperature sensor, thermostat, or other components as needed.