Note On Intermittents
Manipulate circuit No. 410 wiring, ECT sensor connector and PCM connector while observing PCM Data PD04. If engine coolant temperature jumps from normal reading to 298°F (148°C) or greater, repair intermittent short to ground on circuit No. 410. Remove and reconnect both ECT and PCM connectors and retest before replacing any components. If wiring and connectors are okay, substitute a known good ECT sensor and retest.