Circuit/System Testing

WARNING: This page is about a different car, the 2016 Cadillac CT6. However, it is still accessible from the selected car via links, so may be relevant.

NOTE:

It may take up to 2 min for all vehicle systems to power down before an accurate ground or low reference circuit continuity test can be performed.

Ignition/Vehicle Off and all vehicle systems Off.
Disconnect the electrical connector:P19B Speaker - Center Instrument Panel
Test for less than 10 ohm; between the test points:Ground circuit terminal 10 @Component harness&Ground
- If 10 ohm; or greater
1. Disconnect the ground connection: G202
2. Test for less than 2 ohm; between the test points:Ground circuit terminal 10@Component harness&;Ground
  - If 2 ohm; or greater » Repair the open/high resistance in the circuit.
  - If less than 2 ohm; » Repair the open/high resistance in the ground connection.
- If less than 10 ohm;
Verify a test lamp turns On between the test points:B+ circuit terminal 5&Ground
- If the test lamp does not turn On and the circuit fuse is OK
1. Remove the test lamp.
2. Test for less than 2ohm; between the test points:B+ circuit terminal 5& Fuse
  - If 2ohm; or greater » Repair the open/high resistance in the circuit.
  - If less than 2ohm; » Verify the fuse is OK and there is voltage at the fuse.
- If the test lamp does not turn On and the circuit fuse is open
1. Remove the test lamp.
2. Test for infinite resistance between the test points:B+ circuit terminal 5&Ground
  - If less than infinite resistance » Repair the short to ground on the circuit.
  - If infinite resistance » Replace the component:P19B Speaker- Center Instrument Panel.
- If the test lamp turns On
Ignition/Vehicle Off, remove the test lamp.
Disconnect the electrical connector:T3 Audio Amplifier
Ignition On/Vehicle in Service Mode.
Test for less than 1 V between the test points:
- Signal circuit terminal 3@Component harness&Ground
- Signal circuit terminal 4@Component harness&Ground
- Signal circuit terminal 7@Component harness&Ground
- Signal circuit terminal 8@Component harness&Ground
- Signal circuit terminal 9@Component harness&Ground
- If 1 V or greater » Repair the short to voltage on the circuit.
- If less than 1 V
1. Test for infinite resistance between the test points:
  - Signal circuit terminal 3&Ground
  - Signal circuit terminal 4&Ground
  - Signal circuit terminal 7&Ground
  - Signal circuit terminal 8&Ground
  - Signal circuit terminal 9&Ground
  - If less than infinite resistance » Repair the short to ground on the circuit.
  - If infinite resistance
2. Test for less than 2 ohm; between the test points:
  - Signal circuit terminal 3@Component harness&Terminal 13@Control module harness
  - Signal circuit terminal 4@Component harness&Terminal 12@Control module harness
  - Signal circuit terminal 7@Component harness&Terminal 11@Control module harness
  - Signal circuit terminal 8@Component harness&Terminal 15@Control module harness
  - Signal circuit terminal 9@Component harness&Terminal 14@Control module harness
  - If 2 ohm; or greater » Repair the open/high resistance in the circuit.
  - If less than 2 ohm;Replace the component:P19B Speaker - Center Instrument Panel
Ignition On/Vehicle in Service Mode.Radio=
Verify the center speakers raise from dashboard.
- If speakers do not raise from dashboard
  Replace the component:T3 Audio Amplifier
- If speakers do raise from dashboard
All OK.