Test NTC-12: Checking Pcm Power & Grounds

NOTE: For connector terminal ID, see CONNECTOR IDENTIFICATION . For wiring diagram, see WIRING DIAGRAMS article.

Ensure ignition is off. Disconnect connectors at Powertrain Control Module (PCM). PCM is located in engine compartment, between air cleaner and radiator. Using test light, check for voltage at fused B+ circuit at PCM connector terminal No. 46 (Red/White wire). If test light illuminates brightly, go to next step. If test light does not illuminate brightly, repair high resistance on Red/White between PCM, fuse No. 21 and the battery. Fuse No. 21 is located in Power Distribution Center (PDC) at driver's side rear corner of engine compartment. Perform TEST VER-1A .
Ensure ignition is on with engine off. Using test light, check for voltage at PCM connector terminal No. 20 (Dark Blue/White wire). If test light illuminates brightly, go to next step. If test light does not illuminate brightly, repair open Dark Blue/White wire between fuse No. 10 and PCM. This is the fused ignition switch output circuit which goes from the ignition switch, through fuse No. 10 and to PCM and several other components. Fuse No. 10 is located in fuse block on end of instrument panel at driver's side door opening. Perform TEST VER-1A .
Turn ignition off. Connect lead of test light to positive battery connection. Using test light, check for voltage at PCM connector terminals No. 10 (Black/Tan wire), No. 47 (Black/White wire) and No. 50 (Black/Tan wire). These are the ground circuits for the PCM. If test light illuminates brightly, ground circuit is okay. If test light does not illuminate brightly, repair appropriate open ground circuit between PCM and ground. Perform TEST VER-1A .