Circuit/System Testing

WARNING: This page is about a different car, the 2022 Cadillac CT4. However, it is still accessible from the selected car via links, so may be relevant.

Ignition OFF, disconnect the harness connector at the appropriate P19 Speaker.
Ignition On/Vehicle in Service Mode. Infotainment system ON, mute OFF.
Test for 5 - 7 V between the appropriate signal circuit terminals listed below and ground.
- door, I/P speakers, surround audio, and subwoofer (-) circuit terminal 1
- door, I/P speakers, surround audio, and subwoofer (+) circuit terminal 2
- If less than 5 V
1. Ignition OFF, disconnect the X1 and X2 harness connectors at the T3 Audio Amplifier.
2. Test the appropriate circuit for a short to ground.
  - If a short to ground is found, repair the circuit fault.
  - Go to next step: If a short to ground is not found
3. Test the appropriate circuit for an open/high resistance.
  - If an open/high resistance is found, repair the circuit fault.
  - Go to next step: If an open/high resistance is not found
4. Replace the T3 Audio Amplifier
- If greater than 7 V
1. Ignition OFF, disconnect the X1 and X2 harness connectors at the T3 Audio Amplifier. Ignition On/Vehicle in Service Mode.
2. Test the appropriate circuit for a short to voltage:
  - If a short to voltage is found, repair the circuit fault.
  - Go to next step: If a short to voltage is not found
3. Replace the T3 Audio Amplifier
- Go to next step: If 5 - 7 V
Disconnect the appropriate harness connector at the T3 Audio Amplifier
Test for infinite resistance between signal circuit terminal 1 and signal circuit terminal 2 at the appropriate P19 Speaker.
- If less than infinite resistance
  Repair the short between the two signal circuits.
- Go to next step: If infinite resistance
Test or replace the P19 Speaker.