Ground Circuits

Using an ohmmeter, check for continuity to ground at PCM ground terminals. Resistance should be zero ohms. If not, repair open to ground.
Using a voltmeter, connect negative lead of a voltmeter to a good ground. Backprobe positive lead of voltmeter to each ground terminal. With vehicle running, voltmeter should indicate less than one volt. If voltmeter reading is more than one volt, check for open, short to voltage, corrosion or loose connection on ground circuit.