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Home >> Infiniti >> 2003 >> Q45 >> Repair and Diagnosis >> Engine Performance >> System >> Engine Controls - Self-Diagnostics >> Diagnostic Tests >> DTC P0128: Thermostat Function >> Description
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DTC P0128: Thermostat Function: Description

Engine coolant temperature has not risen enough to open the thermostat even though the engine has run long enough. This is due to a leak in a seal or the thermostat is stuck open.