Circuit/System Testing

WARNING: This page is about a different variant/trim than selected.

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: B150 Fuel Tank Pressure Sensor
Test for less than 5 ohms between the test points: Low Reference circuit terminal 2 & Ground
- If 5 ohms or greater
1. Disconnect the electrical connector: K20 Engine Control Module
2. Test for less than 2 ohms between the test points: Low Reference circuit terminal 2@Component harness & Terminal 20 X3@ 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 5 ohms
Ignition - On / Vehicle - In Service Mode
Test for 4. 8 to 5. 2 V between the test points: 5 V Reference circuit terminal 3 & Low Reference circuit terminal 2
- If less than 4. 8 V
1. Ignition/Vehicle - Off
2. Disconnect the electrical connector: K20 Engine Control Module
3. Test for infinite resistance between the test points: 5 V Reference circuit terminal 3@ 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 3@ Component harness & Terminal 8 X3@ 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 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 3@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: Fuel Tank Pressure Sensor = Less than 0. 2 V
- If 0. 2 V or greater
1. Ignition/Vehicle - Off
2. Disconnect the 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 1@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. 2 V
Connect a 3 A fused jumper wire between the test points: Signal circuit terminal 1 & 5 V Reference circuit terminal 3
Verify the scan tool parameter: Fuel Tank Pressure Sensor = Greater than 4. 7 V
- If 4. 7 V or less
1. Ignition/Vehicle - Off & Remove - Jumper wire(s)
2. Disconnect the electrical connector: K20 Engine Control Module
3. Test for infinite resistance between the test points: Signal circuit terminal 1@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 1@Component harness & Terminal 68 X3@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. 7 V
Test or replace the component: B150 Fuel Tank Pressure Sensor