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No Response From PCM (PCI Bus)

NOTE: After making any repairs, perform POWERTRAIN VERIFICATION TEST  under VERIFICATION TESTS.
  1. Turn ignition off. Connect scan tool to Data Link Connector (DLC). DLC is located on bottom of instrument panel, to left of brake pedal. See Figure. Turn ignition on. Using scan tool, attempt to communicate with other modules. If scan tool communicates with other modules, go to next step. If scan tool does not communicate with other modules, proceed to NO RESPONSE FROM PCI (PCI BUS)  test.
  2. Turn ignition off. Disconnect Powertrain Control Module (PCM) 40-pin C1 Black and 40-pin C2 Gray connectors. See Figure. Check, clean and repair connectors as necessary. Turn ignition on. Connect 12-volt test light between PCM C2 connector terminal No. 46, fused B+ circuit (Red/White wire) and ground. If test light illuminates brightly, go to next step. If test light does not illuminate brightly, repair Red/White wire for open or high resistance.
  3. Connect 12-volt test light between battery voltage and PCM connector C1 terminal No. 10, ground circuit (Black/Tan wire), PCM connector C2 terminal No. 50, ground circuit (Black/Tan wire) and PCM connector C2 terminal No. 47, ground circuit (Black/White wire) one at a time. If test light illuminates brightly at all ground circuit terminals, go to next step. If test light does not illuminate brightly at one or more ground circuit terminals, repair wire(s) for open or high resistance.
  4. Turn ignition on. Connect 12-volt test light between PCM C1 connector terminal No. 20, fused ignition switch output circuit (Dark Blue/White wire) and ground. If test light illuminates brightly, go to next step. If test light does not illuminate brightly, repair Dark Blue/White wire for open or high resistance.
  5. Ensure ignition is off. Reconnect PCM connectors. Using scan tool, read PCM DTCs. If scan tool reads DTCs, go to next step. If vehicle starts and scan tool cannot read DTCs, perform NO RESPONSE FROM PCM (SCI ONLY) test under STARTING in SELF-DIAGNOSTICS - PT CRUISER article in ENGINE PERFORMANCE. If vehicle does not start and scan tool cannot read DTCs, perform ENGINE CRANKS DOES NOT START test under STARTING in SELF-DIAGNOSTICS - PT CRUISER article in ENGINE PERFORMANCE.
  6. Turn ignition off. Disconnect PCM connectors. Connect Scope Input Cable (CH7058) to channel one connector on scan tool. Connect Red and Black leads, and Cable-to-Probe Adapter (CH7062) to scope input cable. Using scan tool, select DRB STANDALONE, LAB SCOPE, LIVE, then 12-VOLT SQUARE WAVE. Press F2 for scope. Press F2 again and use down arrow to set voltage range to 20 volts. Press F2 again. Connect Black lead to PCM C2 harness connector terminal No. 47, ground circuit (Black/White wire). Connect Red lead to Gray 40-pin PCM C2 connector terminal No. 59, PCI bus circuit (Violet/Yellow wire). Go to next step.
  7. Turn ignition on. Observe voltage display on scan tool lab scope. If voltage pulses from zero to about 7.5 volts, replace PCM. See POWERTRAIN CONTROL MODULE  under REMOVAL & INSTALLATION. If voltage remains at zero volts, repair open Violet/Yellow wire to PCM.
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