Toyota Tundra Service Manual > Sfi System: Thermostat (P0128)
DESCRIPTION This DTC is stored when the Engine Coolant Temperature (ECT) does not reach 75°C (167°F) despite sufficient engine warm-up time having elapsed. DTC No. DTC Detection Condition Trouble Area P0128 Conditions (a), (b) and (c) met for 5 seconds (2 trip detection logic): (a) Cold start (b) ...
