Dodge Ram 2004 Service Manual page 295

*NO RESPONSE FROM INSTRUMENT CLUSTER —
TEST
4 Turn the ignition off.
Disconnect the Instrument Cluster harness connectors.
Using a 12-volt test light connected to ground, probe each Fused B+ circuit.
Is the test light illuminated for each circuit?
Yes → Go To 5
→ Repair the Fused B+ circuit for an open or short. Refer to the
No
5 Note: Ensure there is PCI Bus communication with other modules on the
vehicle before proceeding. If not, refer to the symptom list from the menu
and repair as necessary.
Disconnect the Instrument Cluster harness connectors.
Use Scope input cable CH7058, Cable to Probe adapter CH7062, and the red and
black test probes.
Connect the scope input cable to the channel one connector on the DRB. Attach the
red and black leads and the cable to probe adapter to the scope input cable.
With the DRBIII select Pep Module Tools.
Select lab scope.
Select Live Data.
Select 12 volt square wave.
Press F2 for Scope.
Press F2 and use the down arrow to set voltage range to 20 volts. Press F2 again
when complete.
Connect the Black lead to the chassis ground. Connect the Red lead to the PCI Bus
circuit in the Instrument Cluster connector.
Turn the ignition on.
Observe the voltage display on the DRB Lab Scope.
Does the voltage pulse from 0 to approximately 7.5 volts?
Yes → Replace the Instrument Cluster in accordance with the service
→ Repair the PCI Bus circuit for an open.
No
ACTION
wiring diagrams in the service information.
Perform BODY VERIFICATION TEST - VER 1.
information.
Perform BODY VERIFICATION TEST - VER 1.
Perform BODY VERIFICATION TEST - VER 1.
281
COMMUNICATION
Continued
APPLICABILITY
All
All