Test 41, Check Saw For Short In EDIS Module
WARNING: This page does not describe the selected car, but rather 11 other vehicles, including the 1991 Ford Ranger, 1991 Ford RV Cutaway, 1991 Ford Pickup, 1991 Ford F-Super Duty, and 1991 Ford Explorer. However, it is still accessible from the selected car via links, so may be relevant.
With key off, connect ECA. Set DVOM to 20-volt scale. Push EDIS diagnostic cable SAW button. Start engine, and measure voltage between breakout box pins No. (+) J21 (EDIS diagnostic cable SAW detector) and (-) J7 (BAT -). If voltage is 5-7 volts, SAW is shorted in EDIS module. Replace EDIS module. Remove all test equipment, and reconnect all components. Clear Continuous Memory, and check for fault codes. If voltage is not 5-7 volts, go to next test.