Power & Ground Circuits
Locate Powertrain Control Module (PCM) in engine compartment, on left side of firewall. Using DVOM, backprobe appropriate power and ground circuits. For terminal identification, see PIN VOLTAGE CHART S article. If power and ground circuits are open or have excessive resistance, clean or repair circuit. See appropriate WIRING DIAGRAMS article. PCM chassis ground is located next to PCM, on firewall.