Ground Circuits
- Using an ohmmeter, check for continuity to ground on ECU terminals No. 6, 13, 39, 48, 108, and 116 on G20 model, or ECU terminals No. 10, 20, 50, 60, 107, 108 and 116 on M30. Resistance should be zero ohm. If reading is not zero ohm, repair open to ground.
- Using a DVOM, touch negative lead of voltmeter to a good ground. Using positive lead of voltmeter, backprobe each ground terminal at ECU connector. With vehicle running, voltmeter should indicate less than one volt. If voltmeter reading is greater than one volt, check for open, corrosion or loose connection on ground lead.