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No Response From Radio

  1. Turn ignition on. Using scan tool, select BODY, then BCM. Determine if communication was able to be established. Select PASSIVE RESTRAINTS, then AIR BAG. Determine if communication was able to be established. If communication is possible with both modules, go to next step. If communication cannot be established with one or both modules, go to PCI BUS COMMUNICATIONS FAILURE . Perform BODY VERIFICATION TEST  under VERIFICATION TESTS.
  2. Turn ignition off. Remove and inspect fuse No. 30 (15-amp) located in Power Distribution Center (PDC) located in right front corner of engine compartment between right fender and battery. See Figure. If fuse is blown, go to next step. If fuse is okay, go to step  6.
  3. Replace blown fuse No. 30 with a good fuse. Turn ignition on. Remove and inspect fuse No. 30 again. If fuse is blown, go to next step. If fuse is okay, check for intermittent short to ground in White/Red wire between radio and junction block. Perform BODY VERIFICATION TEST  under VERIFICATION TESTS.
  4. Replace blown fuse No. 30 with a good fuse. Disconnect radio connectors. Turn ignition on. Remove and inspect fuse No. 30 again. If fuse is blown, go to next step. If fuse is okay, replace radio. Perform BODY VERIFICATION TEST  under VERIFICATION TESTS.
  5. Turn ignition off. Disconnect junction block connector C3. See Figure. Using DVOM, measure resistance between radio connector C1 terminal No. 6 (White/Red wire) and ground. See Figure. If resistance is less than 5 ohms, repair short to ground in White/Red wire between radio and junction block. Perform BODY VERIFICATION TEST  under VERIFICATION TESTS. If resistance is greater than 5 ohms, replace junction block. Perform BODY VERIFICATION TEST  under VERIFICATION TESTS.
  6. Ensure fuse No. 30 is installed in junction block. Disconnect Gray radio connector C1. Using DVOM, measure voltage between radio connector C1 terminal No. 6 (White/Red wire) and ground. See Figure. If voltage is greater than 10 volts, go to next step. If voltage is less than 10 volts, repair open in White/Red wire between radio and junction block. Perform BODY VERIFICATION TEST  under VERIFICATION TESTS.
  7. Disconnect Gray radio connector C1. Using DVOM, measure voltage between radio connector C1 terminal No. 7 (Red/White wire) and ground. See Figure. If voltage is greater than 10 volts, go to next step. If voltage is less than 10 volts, repair open in Red/White wire between radio and junction block. Perform BODY VERIFICATION TEST  under VERIFICATION TESTS.
  8. Using DVOM, measure resistance between radio ground strap terminal connection at radio and ground (this is a ground strap that attaches to rear of radio). If resistance is less than 5 ohms, go to next step. If resistance is greater than 5 ohms, replace radio ground strap. Perform BODY VERIFICATION TEST  under VERIFICATION TESTS.
  9. Disconnect White radio connector C3. Use Scope Input Cable (CH7058), Cable-To-Probe Adapter (CH7062) and Red and Black test probes. Connect scope input cable to channel one connector on scan tool. Attach Red and Black test probes and cable-to-probe adapter to scope input cable. Select scan tool STANDALONE function. Select LAB SCOPE. Select LIVE. Select 12 VOLT SQUARE WAVE. Press F2 for scope display. Press F2 and use down arrow to select voltage range to 20 volts. Press F2 after selecting 20 volts. Connect Black test probe lead to ground and Red test probe lead to radio connector C3 terminal No. 1 (Yellow/Violet/Dark Blue wire). See Figure. Turn ignition on. Observe voltage readings on scan tool. If reading pulses from zero to approximately 7.5 volts, go to next step. If reading is steady at zero volts, repair PCI bus circuit (Yellow/Violet/Dark Blue wire) between radio and diagnostic junction port. See appropriate wiring diagram in DATA LINK CONNECTORS article in WIRING DIAGRAMS. Perform BODY VERIFICATION TEST  under VERIFICATION TESTS.
  10. Replace radio. Perform BODY VERIFICATION TEST  under VERIFICATION TESTS.
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