Dodge Ram 2004, Service Manual

Page: 314 / 642

TEST ACTION APPLICABILITY
3 Turn the ignition off.
Disconnect the PCM/ECM harness connector. Note: If equipped with NGC follow the
caution below.
CAUTION: DO NOT PROBE THE PCM HARNESS CONNECTORS. PROBING
THE PCM HARNESS CONNECTORS WILL DAMAGE THE PCM TERMI-
NALS RESULTING IN POOR TERMINAL TO PIN CONNECTION. INSTALL
MILLER SPECIAL TOOL #8815 TO PERFORM DIAGNOSIS.
Disconnect the DRB from the Data Link Connector (DLC).
Disconnect the negative battery cable.
Measure the resistance of the PCI Bus circuit between the Data Link Connector
(DLC) and the PCM/ECM harness connector.
Is the resistance below 5.0 ohms? All
Yes
→
Go To 4
No
→
Repair the PCI Bus circuit for an open.
Perform BODY VERIFICATION TEST - VER 1.
4 NOTE: Reconnect the PCM/ECM harness connector and the negative bat-
tery cable.
Turn the ignition on.
Measure the voltage of the PCI Bus circuit at the Data Link Connector (DLC).
Is the voltage above 7.0 volts? All
Yes
→
Go To 5
No
→
Go To 6
5 Turn the ignition off.
Using a voltmeter, connect one end to the PCI Bus circuit at the DLC, and the other
end to ground.
Note: When performing the next step turn the ignition off (wait one minute)
before disconnecting any module. When the module is disconnected turn
the ignition on to check for a short to voltage.
Turn the ignition on.
While monitoring the voltmeter, disconnect each module the vehicle is equipped with
one at a time.
Is the voltage steadily above 7.0 volts with all the modules disconnected? All
Yes
→
Repair the PCI Bus circuit for a short to voltage.
Perform BODY VERIFICATION TEST - VER 1.
No
→
Replace the module that when disconnected the short to voltage
was eliminated.
Perform BODY VERIFICATION TEST - VER 1.
300
COMMUNICATION
*PCI BUS COMMUNICATION FAILURE —
Continued