Circuit/System Testing

WARNING: This page is about a different car, the 2020 Buick Regal TourX, 2020 Buick Regal, 2019 Buick Regal TourX, and 2019 Buick Regal. However, it is still accessible from the selected car via links, so may be relevant.

NOTE:

This diagnostic is only to be used when the P17 Display and the A22 Controls are separate units.

Ignition/Vehicle & All vehicle systems - Off
Disconnect the electrical connector: @ A22 Radio Controls
Test for less than 10 ohms between the test points: Low Reference circuit terminal 4 & Ground
- If 10 ohms or greater
1. Disconnect the electrical connector: X1 @ P17 Info Display Module
2. Test for less than 2 ohms between the test points: Low Reference circuit terminal 4 & The other end of the circuit
  - If 2 ohms or greater - Repair the open/high resistance in the circuit.
  - If less than 2 ohms - Replace the component: P17 Info Display Module
- Go to next step: If less than 10 ohms
Ignition/Vehicle - On
Test for 3 to 3.5 V between the test points:
- Signal circuit terminal 3 @ A22 Radio Controls & Ground
- Signal circuit terminal 6 @ A22 Radio Controls & Ground
- Signal circuit terminal 7 @ A22 Radio Controls & Ground
- Signal circuit terminal 8 @ A22 Radio Controls & Ground
- If less than 3 V
1. Ignition/Vehicle & All vehicle systems - Off
2. Disconnect the electrical connector: X1 @ A11 Radio
3. Test for infinite resistance between the test points:
  - Signal circuit terminal 3 @ A22 Radio Controls & Ground
  - Signal circuit terminal 6 @ A22 Radio Controls & Ground
  - Signal circuit terminal 7 @ A22 Radio Controls & Ground
  - Signal circuit terminal 8 @ A22 Radio Controls & Ground
  - If less than infinite resistance - Repair the short to ground on the circuit.
  - Go to next step: If infinite resistance
4. Test for less than 2 ohms between the test points:
  - Signal circuit terminal 3 @ A22 Radio Controls & Terminal 24 X1 @ A11 Radio
  - Signal circuit terminal 6 @ A22 Radio Controls & Terminal 25 X1 @ A11 Radio
  - Signal circuit terminal 7 @ A22 Radio Controls & Terminal 26 X1 @ A11 Radio
  - Signal circuit terminal 8 @ A22 Radio Controls & Terminal 27 X1 @ A11 Radio
  - If 2 ohms or greater - Repair the open/high resistance in the circuit.
  - If less than 2 ohms - Replace the component: A11 Radio
- If greater than 3.5 V
1. Ignition/Vehicle & All vehicle systems - Off
2. Disconnect the electrical connector: X1 @ A11 Radio
3. Test for less than 1 V between the test points:
  - Signal circuit terminal 3 @ A22 Radio Controls & Ground
  - Signal circuit terminal 6 @ A22 Radio Controls & Ground
  - Signal circuit terminal 7 @ A22 Radio Controls & Ground
  - Signal circuit terminal 8 @ A22 Radio Controls & Ground
  - If greater than 1 V
    Repair the short to voltage on the circuit.
  - If less than 1 V - Replace the component: A11 Radio
- Go to next step: If between 3 and 3.5 V
Replace the component: A22 Radio Controls