Circuit/System Testing

WARNING: This page is about a different car, the 2009 Cadillac DTS. However, it is still accessible from the selected car via links, so may be relevant.

With UE1

Ignition OFF, disconnect the X3 harness connector at the communication interface module.
Ignition ON, test for 9.5-10.5 volts between the voice recognition signal circuit terminal 2 and ground.
- If less than specified range, test the signal circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the radio.
- If greater than specified range, test the signal circuit for a short to voltage. If the circuit tests normal, replace the radio.
Test for 9.5-10.5 volts between the voice recognition signal circuit terminal 2 and the voice recognition low reference circuit terminal 4.
- If less than the specified range, test the low reference circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the radio.
If all circuits test normal, replace the communication interface module.

Without UE1

Ignition OFF, disconnect the harness connector at the cellular microphone.
Ignition ON, test for 9.5-10.5 volts between the signal circuit terminal B and ground.
- If greater than the specified range, test the signal circuit for a short to voltage. If the circuit tests normal, replace the radio.
- If less than the specified range, test the signal circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the radio.
Test for test for 9.5-10.5 volts between the signal circuit terminal B and the drain circuit terminal A.
- If less than the specified range, test the drain circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the radio.
If all circuits test normal, replace the cellular microphone.