No Response From PCM (PCI Bus)

WARNING: This page is about a different car, the 2002 Dodge Dakota. However, it is still accessible from the selected car via links, so may be relevant.

Possible Causes:

PCM PCI no response.
PCI Bus circuit open.
PCM.

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 .

Testing:

Turn ignition off. Connect DRBIII(R) to DLC. Turn ignition on. Select BODY, then BODY COMPUTER. Using the DRBIII(R), attempt to communicate with the CAB, EMIC, then ACM. As soon as one or more modules communicates with the DRBIII(R), answer the question. Is DRBIII(R) able to identify or communicate with either the CAB, EMIC or ACM? If yes, go to next step. If no, see PCI BUS COMMUNICATION FAILURE .

NOTE: If vehicle will not start and DRBIII(R) displays a no start DTC, refer to NO-START DIAGNOSIS in BASIC DIAGNOSTIC PROCEDURES - DAKOTA & DURANGO article in ENGINE PERFORMANCE.

Using the DRBIII(R), attempt to display PCM DTCs (this will ensure Power and Ground circuits to PCM are operational). Is DRBIII(R) able to display PCM DTCs? If no, see NO RESPONSE FROM PCM (SCI ONLY) . If yes, turn ignition off. Disconnect PCM C3 harness connector. Connect Scope Input Cable (CH7058) to channel one connector on DRBIII(R). Connect Cable-To-Probe Adapter (CH7062) and Black and Red test probes to scope input cable. Using the DRBIII(R), select PEP MODULE TOOLS, LAB SCOPE, LIVE DATA and 12 VOLT SQUARE WAVE. Press F2 for SCOPE. Press F2 and use DOWN arrow to set voltage scale to 20 volts. Set probe to x10. Press F2 again when complete. Connect Black test probe to ground. Connect Red test probe to PCM C3 harness connector terminal No. 30. Turn ignition on. Observe DRBIII(R) lab scope. Does voltage toggle from zero to approximately 7.5 volts? See Figure -Figure . If yes, replace PCM. Perform POWERTRAIN CONTROL MODULE VERIFICATION TEST under VERIFICATION TESTS. If no, repair open in PCI Bus circuit. Perform POWERTRAIN CONTROL MODULE VERIFICATION TEST under VERIFICATION TESTS.