Notes On Intermittents
WARNING: This page is about a different car, the 1988 Cadillac Seville and 1988 Cadillac Eldorado. However, it is still accessible from the selected car via links, so may be relevant.
Manipulate Transmission connector, ECM connector, and wiring of circuit No. 520 while observing ECM parameter ED26. If fault is induced, the data value will jump from a normal reading to a low or high reading. If so, repair open or short in circuit No. 520.
Unplug and plug the ECM transmission connectors and ensure they are latched properly. If wiring and connectors are okay, substitute a known good sensor and retest.
Review snapshot data parameters stored with this code to verify failure. If failure is verified, check and repair intermittent wiring connections or sensor.