Diagnostic Aids
WARNING: This page is about a different variant/trim than selected.
- DTC P0128 is designed to detect a faulty thermostat.
- A skewed low ECT sensor can cause a DTC P0128 to set.
- A thermostat that is stuck open can cause a DTC P0128 to set. A high resistance short from the signal circuit to the low reference circuit can cause this DTC to set.