Diagnostic Aids
WARNING: This page is about a different car, the 2002 Pontiac Montana, 2002 Oldsmobile Silhouette, and 2002 Chevrolet Venture. However, it is still accessible from the selected car via links, so may be relevant.
- A DTC P0128 is designed to detect a faulty thermostat.
- A skewed ECT sensor may cause a P0128 to set.
- If DTC P0125 and DTC P0128 are both set, a skewed ECT sensor is the most likely cause.
- A skewed IAT sensor may cause this DTC to set.