Ground Circuit
- Turn ignition off. Locate ECM in engine compartment, between front and rear firewall partitions, on left side. Connect negative lead of ohmmeter to ground. Backprobe ECM terminals No. 24 (Black/White wire), No. 25 (Black/White wire), No. 46 (Black wire), and No. 47 (Black wire). Resistance should be zero ohms for each wire. If resistance is as specified, go to next step. If resistance is not as specified, repair open to ground.
- Connect negative lead of DVOM to a good ground. Backprobe each terminal specified in step 1). With vehicle running, DVOM should indicate less than one volt. If voltage is not as specified, inspect for open, corrosion, or loose connection on appropriate ground lead.