Conditions for Setting the DTC: P0128
WARNING: This page is about a different car, the 2008 Suzuki Swift +, 2008 Pontiac Wave, and 2008 Chevrolet Aveo. However, it is still accessible from the selected car via links, so may be relevant.
The ECM detects that the amount of time it takes for the ECT to reach maximum temperature has exceeded a calibrated time.