Dodge Ram 2004 Service Manual page 305

*NO RESPONSE FROM RADIO —
TEST
4 Turn the ignition off.
Disconnect the Radio harness connector.
Using a 12-volt test light connected to 12-volts, probe both ground circuits.
Is the test light illuminated for both circuits?
Yes → Go To 5
→ Repair the ground circuit for an open.
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 Radio harness connector.
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 Radio 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 Radio.
→ Repair the PCI Bus circuit for an open.
No
Continued
ACTION
Perform BODY VERIFICATION TEST - VER 1.
Perform BODY VERIFICATION TEST - VER 1.
Perform BODY VERIFICATION TEST - VER 1.
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COMMUNICATION
APPLICABILITY
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All