Circuit/System Testing

WARNING: This page is about a different car, the 2019 Buick Cascada, 2018 Buick Cascada, and 2017 Buick Cascada. 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 & All vehicle systems - Off
Disconnect the electrical connector: B22 Brake Pedal Position Sensor
Test for less than 10 ohms between the test points: Low Reference circuit terminal 6/A & Ground
- If 10 ohms or greater
1. Disconnect the appropriate electrical connector: K20 Engine Control Module
2. Test for less than 2 ohms between the test points: Low Reference circuit terminal 6/A@Component harness & The other end of the circuit@ Control module harness
  - If 2 ohms or greater - Repair the open/high resistance in the circuit.
  - If less than 2 ohms - Replace the component: K20 Engine Control Module
- Go to next step: If less than 10 ohms
Ignition - On / Vehicle - In Service Mode
Test for 4.8 to 5.2 V between the test points: 5 V Reference circuit terminal 5/B & Low Reference circuit terminal 6/A
- If less than 4.8 V
1. Ignition/Vehicle - Off
2. Disconnect the appropriate electrical connector: K20 Engine Control Module
3. Test for infinite resistance between the test points: 5 V Reference circuit terminal 5/B@ Component harness & 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: 5 V Reference circuit terminal 5/B@ Component harness & The other end of the circuit@ Control module harness
  - If 2 ohms or greater - Repair the open/high resistance in the circuit.
  - If less than 2 ohms - Replace the component: K20 Engine Control Module
- If greater than 5.2 V
1. Ignition/Vehicle - Off
2. Disconnect the appropriate electrical connector: K20 Engine Control Module
3. Ignition - On / Vehicle - In Service Mode
4. Test for less than 1 V between the test points:5 V Reference circuit terminal 5/B@Component harness & Ground
  - If 1 V or greater - Repair the short to voltage on the circuit.
  - If less than 1 V - Replace the component: K20 Engine Control Module
- Go to next step: If between 4.8 and 5.2 V
Verify the scan tool parameter: Brake Pedal Position Sensor =Less than 0.25 V
- If 0.25 or greater
1. Ignition/Vehicle - Off
2. Disconnect the appropriate electrical connector: K20 Engine Control Module
3. Ignition - On / Vehicle - In Service Mode
4. Test for less than 1 V between the test points: Signal circuit terminal 4/C@Component harness & Ground
  - If 1 V or greater - Repair the short to voltage on the circuit.
  - If less than 1 V - Replace the component: K20 Engine Control Module
- Go to next step: If less than 0.25 V
Connect a 3 A fused jumper wire between the test points: Signal circuit terminal 4/C & 5 V Reference circuit terminal 5/B
Verify the scan tool parameter: Brake Pedal Position Sensor =Greater than 4.8 V
- If 4.8 V or less
1. Ignition/Vehicle - Off & Remove - Jumper wire(s)
2. Disconnect the appropriate electrical connector: K20 Engine Control Module
3. Test for infinite resistance between the test points: Signal circuit terminal 4/C@Component harness & 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 4/C@Component harness & The other end of the circuit@Control module harness
  - If 2 ohms or greater - Repair the open/high resistance in the circuit.
  - If less than 2 ohms - Replace the component: K20 Engine Control Module
- Go to next step: If greater than 4.8 V
Test or replace the component: B22 Brake Pedal Position Sensor