PCI BUS Communication Failure

Possible Causes:

No commununication from module(s) on PCI Bus.
PCI Bus circuit open at the DLC.
PCI Bus circuit shorted to ground.
PCI Bus circuit shorted to voltage.
Faulty Module(s).
Wiring harness intermittent failure.

CAUTION: Always turn ignition off before disconnecting or connecting any control module connector. Failure to do so could result in damage to control module.

NOTE: Ensure vehicle being tested has a fully charged battery. If it does not, false symptoms may occur.

NOTE: For component location, see appropriate illustration under COMPONENT LOCATIONS . For terminal identification, see appropriate illustration under CONNECTOR IDENTIFICATION . For circuit and wire color identification, see WIRING DIAGRAMS . For component removal and installation procedures, see appropriate component under REMOVAL & INSTALLATION .

NOTE: Determine which modules this vehicle is equipped with before beginning. To determine which modules this vehicle is equipped with, see WIRING DIAGRAMS .

NOTE: Diagnostic Junction Port and DLC are both Black 16-pin connectors located under left side of instrument panel. However, all wires connected to Diagnostic Junction Port are Violet/Yellow.

Testing:

Turn ignition off. Connect DRBIII(R) to DLC. Connect Diagnostic Junction Port Tester (8339) to DRBIII(R) and Diagnostic Junction Port. Using the DRBIII(R) and diagnostic Junction Port Tester, select JUNCTION PORT TOOL, then PCI BUS MODULE SCAN. Follow instructions on DRBIII(R) and attempt to communicate with modules on PCI Bus. Is DRBIII(R) able to identify or communicate with any modules? If yes, perform appropriate PCI Bus-related NO RESPONSE DTC or symptom test. See DIAGNOSTIC TROUBLE CODE DEFINITIONS and SYMPTOM IDENTIFICATION . If no, go to next step.
Measure resistance between DLC terminal No. 2 and Diagnostic Junction Port terminal No. 5. Is resistance less than 5 ohms? If yes, go to next step. If no, repair open in PCI Bus circuit between Diagnostic Junction Port and DLC. Perform BODY VERIFICATION TEST under VERIFICATION TESTS.
Using the DRBIII(R) and Diagnostic Junction Port Tester, select JUNCTION PORT TOOL, then PCI BUS CONTROL MODE. Follow instructions on DRBIII(R) for each pin that is equipped with a PCI BUS circuit. Does DRBIII(R) display NO MODULES RESPONDING from any of the pins that were scanned? If yes, go to next step. If no, check PCI Bus circuit between Diagnostic Junction Port and DLC for short to ground or short to voltage. Repair as necessary. Perform BODY VERIFICATION TEST under VERIFICATION TESTS.
Disconnect Diagnostic Junction Port Tester from DRBIII(R), but leave connected to Diagnostic Junction Port. Turn ignition on. Using Diagnostic Junction Port Tester, measure voltage on PCI Bus circuit that DRBIII(R) displayed as NO MODULES RESPONDING. Is reading steadily more than 7 volts? If yes, go to next step. If no, go to step 6 .
Measure voltage on PCI Bus circuit(s) on the Diagnostic Junction Port Tester that previously measured more than 7 volts. Turn ignition off. Disconnect the related module harness connector(s). Turn ignition on. Is the voltage steadily more than 7 volts? If yes, repair PCI Bus circuit that measured more than 7 volts for a short to voltage. Perform BODY VERIFICATION TEST under VERIFICATION TESTS. If no, replace module that when disconnected, eliminated the short to voltage. Perform BODY VERIFICATION TEST under VERIFICATION TESTS.
Turn ignition off. Disconnect negative battery cable. Measure resistance between ground and PCI Bus circuit at Diagnostic Junction Port Tester that DRBIII(R) displayed as NO MODULES RESPONDING. Is resistance less than 100 ohms? If yes, go to next step. If no, go to step 8 .
Measure resistance between ground and PCI Bus circuit at Diagnostic Junction Port Tester that previously measure less than 100 ohms. Disconnect module on PCI Bus circuit that scan tool displayed as NO MODULES RESPONDING. Is resistance less than 100 ohms with module disconnected? If yes, repair PCI Bus circuit that measured less than 100 ohms for a short to ground. Perform BODY VERIFICATION TEST under VERIFICATION TESTS. If no, replace module that when disconnected, eliminated the short to ground. Perform BODY VERIFICATION TEST under VERIFICATION TESTS.
Visually inspect PCI Bus-related wiring harness for any chafed, pierced, pinched or partially broken wires. Visually inspect related harness connectors for broken, bent, pushed out or corroded terminals. Were any problems found? If yes, repair as necessary. Perform BODY VERIFICATION TEST under VERIFICATION TESTS. If no, test is complete.