P0128

P0128 THERMOSTAT FUNCTION

DTC Logic

DTC DETECTION LOGIC

NOTE: If DTC P0128 is displayed with DTC P0300, P0301, P0302, P0303 or P304, first perform the trouble diagnosis for DTC P0300, P0301, P0302, P0303, P0304. Refer to EC-243, "DTC Logic". P0300

Engine coolant temperature has not risen enough to open the thermostat even though the engine has run long enough.

This is due to a leak in the seal or the thermostat stuck open.

DTC CONFIRMATION PROCEDURE

Step 1-2:

Diagnosis Procedure

Step 1:

Component Inspection