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Checking Powertrain Control Module Power & Ground Circuits

NOTE: After all repairs in this test, perform POWERTRAIN VERIFICATION TEST  under VERIFICATION TESTS.
  1. Turn ignition off. Disconnect PCM connectors. See Figure -Figure . PCM is located on firewall in right rear corner of engine compartment. Inspect connector for damaged pins, corrosion and loose terminals. Repair connector as necessary. Using a test light connected to ground, probe terminal A22 (Red/White wire) at PCM C1 harness connector. See Figure . If test light illuminates brightly, go to next step. If test light does not illuminate brightly, repair open fused B(+) circuit (Red/White wire) between fuse No. 9 (30-amp) in Power Distribution Center (PDC) and PCM. PDC is located in right side of engine compartment, next to battery. See POWER DISTRIBUTION in SYSTEM WIRING DIAGRAMS article in ELECTRICAL. Also check fuse No. 9 in PDC.
  2. Turn ignition on. Using a test light connected to ground, probe terminal C3 (Dark Blue/Yellow wire) at PCM C3 harness connector. See Figure . If test light illuminates brightly, power circuits are okay. Go to next step. If test light does not illuminate brightly, repair open fused ignition switch output circuit (Dark Blue/Yellow wire) between fuse No. 12 (10-amp) in fuse block and PCM. Also check fuse No. 12 in fuse block, located on firewall next to glove box.
  3. Turn ignition off. Using a test light connected to positive battery voltage, probe terminals A31 (Black/Tan wire) and A32 (Black/Tan wire) at PCM C1 connector. See Figure . If test light illuminates brightly at both terminals, ground circuits are okay. Test is complete. If test light does not illuminate brightly at one or both terminals, repair open in appropriate Black/Tan wire between PCM and ground. Ground connection is located on right rear of cylinder block.
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