PCI Bus Communication Failure

NOTE: Determine modules vehicle is equipped with before performing diagnostic procedure.

NOTE: After making any repairs, perform BODY VERIFICATION TEST under VERIFICATION TESTS.

Connect Diagnostic Junction Port Tester (8339) to diagnostic junction port and scan tool. See COMPONENT LOCATIONS . Using scan tool, select JUNCTION PORT TOOL then PCI BUS MODULE SCAN and follow on screen instructions. If scan tool does not communicate with any modules, go to next step. If scan tool communicates with any modules on vehicle, go to appropriate diagnostic procedure for modules not responding. See DIAGNOSTIC TROUBLE CODE IDENTIFICATION table under SELF-DIAGNOSTIC SYSTEM.
Turn ignition off. Disconnect scan tool from Data Link Connector (DLC). Using DVOM, measure resistance of White/Violet wire between DLC terminal No. 2 and diagnostic junction port terminal No. 7. See Figure. If resistance is 5 ohms or less, go to next step. If resistance is greater than 5 ohms, repair open in White/Violet wire.
Reconnect scan tool to DLC. Connect diagnostic junction port tester to diagnostic junction port and scan tool. Using scan tool, select JUNCTION PORT TOOL then PCI BUS MODULE SCAN and follow on screen instructions. If scan tool displays NO MODULES RESPONDING from any pins that were scanned, go to next step. If scan tool does not display NO MODULES RESPONDING from any pins that were scanned, check for open or short to ground in White/Violet wire between DLC and diagnostic junction port. Repair as necessary.
Disconnect junction port tester from scan tool. Turn ignition on. Measure voltage at junction port tester terminal for suspect module(s) displaying NO MODULES RESPONDING. See Figure. If voltage is approximately 7 volts, go to next step. If voltage not approximately 7 volts, go to step 6.

NOTE: Turn the ignition off before disconnecting any module harness connector then turn the ignition on.

NOTE: If the problem occurred on a bus circuit that has more than one module on the same circuit, observe the voltmeter while disconnecting each module connector one at a time.

Measure the voltage of the PCI Bus circuit on the Diagnostic Junction Port tester that previously measured above 7 volts. Disconnect the module harness connector(s). If the voltage is steadily above 7 volts with the module(s) disconnected, repair the PCI Bus circuit that measured over 7 volts for a short to voltage. If the voltage is not steadily above 7 volts with the module(s) disconnected, replace the module that when disconnected the short to voltage was eliminated.
Turn ignition off. Disconnect negative battery cable. Using DVOM, measure resistance between junction port terminal of suspect module(s) displaying NO MODULES RESPONDING and ground. If resistance is 100 ohms or less, go to next step. If resistance is greater than 100 ohms, go to step 8.

NOTE: If the problem occurred on a bus circuit that has more than one module on the same circuit, observe the ohmmeter while disconnecting each module connector one at a time.

Disconnect the negative battery cable. Measure the resistance between ground and the PCI Bus circuit at the Diagnostic Junction Port tester that previously measured below 100 ohms. Disconnect the module harness connector(s). If the resistance is below 100 ohms with the module(s) disconnected, repair the PCI Bus circuit that measured below 100 ohms for a short to ground. If the resistance is above 100 ohms with the module(s) disconnected, replace the module that when disconnected the short to ground was eliminated.
Visually inspect suspect module harness and connectors for signs of damage. Check for intermittent poor connections or faulty circuits. Repair as necessary. If circuits and connectors are okay, test is complete.