Note On Intermittents
WARNING: This page is about a different car, the 1990 Cadillac Seville and 1990 Cadillac Eldorado. However, it is still accessible from the selected car via links, so may be relevant.
Manipulate circuit No. 472 wiring, MAT sensor and ECM connector while observing ECM parameter ED05. If failure is induced, manifold air temperature will jump from its normal value to shorted reading of 142-151°C. If wiring and connectors are okay, substitute a known good sensor and retest.