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PCI Bus Communication Failure

NOTE: After all repairs in this test, perform BODY VERIFICATION TEST  under VERIFICATION TESTS.
NOTE: If communication errors exist, scan tool will display NO RESPONSE or BUS +/- SIGNALS OPEN.

Possible Causes:

Testing

  1. Confirm vehicle equipment level and module application. Turn ignition on. Using scan tool, attempt to communicate with Air Bag Control Module (ACM), instrument cluster and Sentry Key Immobilizer Module (SKIM), if equipped. If one or more modules communicates, go to next step. If none of the modules communicates, go to step  3 .
  2. Turn ignition off. Check harness connectors, terminals and wiring. Repair as necessary. If all modules communicate test is complete. If one or more modules do not communicate, go to appropriate test.
  3. Turn ignition off. Disconnect Powertrain Control Module (PCM) connector C3. See Figure . Remove scan tool from vehicle. Disconnect negative battery cable. Check resistance of Violet/Yellow wire between PCM connector C3 terminal No. 30 and Data Link Connector (DLC) terminal No. 2. See Figure and Figure . If resistance is less than 5 ohms, go to next step. If resistance is 5 ohms or more, repair open on Violet/Yellow wire.
  4. Connect PCM connector and negative battery cable. Turn ignition on. Measure voltage of PCI bus circuit at DLC terminal No. 2. See . Figure . If voltage is 1.5 volts or more, go to next step. If voltage is less than 1.5 volts, go to step  6 .
  5. Turn ignition off. Wait 2 minutes. Disconnect ACM. See Figure . Turn ignition on. Connect negative battery cable. Measure voltage of PCI bus circuit at DLC terminal No. 2. See Figure . If voltage is less than 1.5 volts, replace ACM. If voltage is still 1.5 volts or more, turn ignition off. Wait one minute. Remove instrument cluster. See INSTRUMENT CLUSTER  under REMOVAL & INSTALLATION. Turn ignition on. Measure voltage of PCI bus circuit at DLC terminal No. 2. If voltage is less than 1.5 volts, replace instrument cluster. If voltage is still 1.5 volts or more and vehicle is not equipped with SKIM, repair short to voltage on Violet/Yellow wire. If voltage is still 1.5 volts or more and vehicle is equipped with SKIM, turn ignition off. Wait one minute. Disconnect SKIM connector. See Figure . Turn ignition on. Measure voltage of PCI bus circuit at DLC terminal No. 2. See Figure . If voltage is less than 1.5 volts, replace SKIM. See SENTRY KEY IMMOBILIZER MODULE  under REMOVAL & INSTALLATION. If voltage is still 1.5 volts or more, repair short to voltage on Violet/Yellow wire.
  6. Turn ignition off. Disconnect negative battery cable. Using ohmmeter, measure resistance between DLC terminal No. 2 and ground. See Figure . Disconnect each module, one at a time. If resistance changes to more than 1000 ohms when a module is disconnected, replace the disconnected module. If resistance is still less than 1000 ohms with all modules disconnected, repair short to ground on Violet/Yellow wire.
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