Note On Intermittents
Manipulate wiring on circuits No. 410 and 1076 (coolant temperature sensor and PCM connector) while observing PCM parameter ED04. If failure is induced, coolant temperature will jump from normal value to open reading (-38°C or less). Repair intermittent open on circuit No. 410 or 1076. Disconnect and reconnect coolant sensor and PCM connectors, and ensure they properly latch. If wiring and connectors are okay, substitute a known good sensor, and retest.