FixVault

Circuit description

When the E.F.I. water temperature sensor detects the coolant temperature, at the same time the ECM estimates the engine coolant temperature. If the difference between the estimated coolant temperature and the actual engine coolant temperature exceeds the predetermined setup value, the DTC is stored and thermostat functional fault is reported.

DTC DETECTION CONDITION

DTC No. DTC detection condition Suspected parts
P0128 A fault in thermostat function is detected.
(2 trips detection logic)
  • Thermostat
  • Cooling system
  • E.F.I. water temperature sensor
  • ECM