Possible Causes
WARNING: This page is about a different car, the 2003 Nissan Pathfinder. However, it is still accessible from the selected car via links, so may be relevant.
DTC P0128 sets when the engine coolant temperature does not reach to specified temperature even though the engine has run long enough. Possible cause is:
- Faulty or open thermostat.
- Leakage from sealing portion of thermostat.
- Engine coolant temperature sensor fault.