Checking Powertrain Control Module (PCM) Power & Ground Circuits (Cherokee)
- Turn ignition off. Disconnect PCM Black C1 connector. PCM is located in engine compartment on left front fender, near radiator support. Inspect connector for damaged pins, corrosion and loose terminals. Repair connector as necessary. Using a test light connected to ground, probe terminal No. 22 (Dark Green/Black wire) at PCM C1 connector. See Fig 1
. If test light illuminates brightly, go to next step. If test light does not illuminate brightly, repair open fused B(+) circuit (Dark Green/Black wire) between PCM and fuse No. 22 (15-amp) in Power Distribution Center (PDC). PDC is located in right side of engine compartment, next to battery. Also check fuse No. 22 in PDC. See WIRING DIAGRAMS article.
- Turn ignition on. Using a test light connected to ground, probe terminal No. 2 (Dark Blue/White wire) at PCM C1 connector. See Fig 1
. 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/White wire) between PCM and fuse No. 11 (20-amp) in junction block. Junction block is located behind passenger-side kick panel. Also check fuse No. 11 in junction block.
- Turn ignition off. Using a test light connected to positive battery voltage, probe terminals No. 31 (Black/Tan wire) and No. 32 (Black/Tan wire) at PCM C1 connector. 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 location is located at right front of cylinder block, near generator.
Courtesy of DAIMLERCHRYSLER CORPORATION