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Home >> Cadillac >> 2000 >> Seville STS >> Repair and Diagnosis >> Engine Performance >> System >> Engine Control System - Self-Diagnostics - 4.6L >> Diagnostic Tests >> DTC P1258: Engine Coolant OVERTEMPERATURE Protection Mode Active >> Circuit Description
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Circuit Description

PCM has the ability to disable 4 injectors during an engine overtemperature (overheating) condition. Engine is considered overtemperature whenever ECT reaches 268°F (131°C). This protection mode allows the PCM to alternate between groups of cylinders, thereby reducing coolant temperature. This is accomplished by disabling the fuel injectors. This DTC is set to show that an overheating condition was or is observed by the PCM and that the protection mode has been engaged.