Ground Circuit Checks
Check ground circuits to ECM for continuity to ground. Using a DVOM, touch negative voltmeter lead to a good ground. Touch positive voltmeter lead to each ground terminal. With vehicle running, voltmeter should indicate less than one volt. If volt-meter reading is greater than one volt, check for open, corrosion or loose connection on ground lead. To identify ECM ground terminals, see WIRING DIAGRAMS article in this section.