Ground Circuits
- Turn ignition off. Using ohmmeter, backprobe each ECM ground terminal. (Terminal Nos. 17, 18, 19, 20, 42, 46, 69, 94, & 94). See appropriate WIRING DIAGRAMS article. Resistance should be zero ohms. If resistance is not close to zero ohms, repair open to ground.
- Start engine. Using voltmeter, backprobe each ground terminal. Voltage should be less than one volt. If voltage is greater than one volt, check for open, corrosion, or loose connection on ground lead.