DTC P0128 Coolant Thermostat (Coolant Temperature Below Thermostat Regulating Temperature): Description
WARNING: This page is about a different car, the 2008 Lexus IS 350. However, it is still accessible from the selected car via links, so may be relevant.
This DTC is set when the Engine Coolant Temperature (ECT) does not reach 75°C (167°F) despite sufficient engine warm-up time.
DTC DETECTION CONDITION CHART
| DTC No. | DTC Detection Condition | Trouble Area |
|---|---|---|
| P0128 | Conditions (a), (b) and (c) are met for 5 seconds (2 trip detection logic):
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