Circuit/System Testing

WARNING: This page is about a different car, the 2018 Chevrolet Suburban 3500 HD. However, it is still accessible from the selected car via links, so may be relevant.

Ignition/Vehicle & All vehicle systems - Off
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.
Disconnect the electrical connector: B22 Brake Pedal Position Sensor
Test for less than 10 ohms between the test points: Low Reference circuit terminal 5 & 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 5 @ 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 6 & Low Reference circuit terminal 5
- 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 6 @ Component harness & Ground
  - If less than infinite resistance - Repair the short to ground on the circuit.
  - If infinite resistance
4. Test for less than 2 ohms between the test points: 5 V Reference circuit terminal 6 @ 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 6 @ 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 @ 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 & 5 V Reference circuit terminal 6
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 @ Component harness & Ground
  - If less than infinite resistance - Repair the short to ground on the circuit.
  - If infinite resistance
4. Test for less than 2 ohms between the test points: Signal circuit terminal 4 @ 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