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Home >> Cadillac >> 2007 >> SRX 3.6 7, AWD >> Repair and Diagnosis >> External Pages >> Different car >> Section 13 (Cellular System, Entertainment System, And Navigation System) >> Diagnostic Information and Procedures >> Radio Poor Reception >> Circuit/System Testing
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Circuit/System Testing

WARNING: This page is about a different car, the 2007 Cadillac STS. However, it is still accessible from the selected car via links, so may be relevant.
IMPORTANT: Perform the Audio System Troubleshooting Hints  to properly identify the customers concern before using this diagnostic.
  1. Disconnect the antenna module harness connector. Turn ON the ignition and the radio. With a DMM verify the battery positive voltage circuit receives B+.
  2. With the ignition OFF, disconnect the coax cable from the radio. With a DMM, verify there is less than 0.20 ohms between the negative battery cable and the coaxial cable metal outer shield.
    • Inspect the antenna module ground (case ground) for a proper connection. If greater than 0.20 ohms, test the antenna module ground for an open. If the antenna module is properly grounded replace the antenna coax cable.
  3. Disconnect the coax cable from the antenna module bracket. With a DMM, verify there is less than 3.5 ohms between the radio end coaxial cable conductor and the antenna module end coaxial cable conductor.
    • If greater than 3.5 ohms, replace the coax cable.
    • If B+ is not present on the remote enable circuit with the ignition and radio ON, test or repair open or short to ground on the remote enable circuit. If open or short to ground can not be found, replace the radio.
  4. Reconnect the coax cable to the radio and the antenna module. Reconnect the antenna module harness connector. Turn ON the ignition and radio. With the scan tool observe and record the signal strength dBuV in the radio data list. Disconnect the coax cable from the radio antenna module bracket and observe the dBuV for a drop in signal strength.
    • If the dBuV displayed on the scan tool did not drop signal strength with the antenna module unplugged, replace the antenna module.
  5. Test for continuity of the individual lines of the antenna grid. Inspect for a improper button connection at the antenna connector (front and rear glass). With a DMM, verify every antenna grid line has continuity end to end.
    • If there is no continuity one or more of the antenna grid lines replace the suspect glass.
    • If all circuits test normal, replace the radio.
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