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: B47 Fuel Pressure Sensor
- Test for less than 10 ohms between the test points: Low Reference circuit terminal 2 & Ground
- If 10 ohms or greater
- Disconnect the electrical connector: X1@K20 Engine Control Module
- Test for less than 2 ohms between the test points: Low Reference circuit terminal 2@Component harness & Terminal 44@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 1 & Low Reference circuit terminal 2
- If less than 4.8 V
- Ignition/Vehicle - Off
- Disconnect the electrical connector: X3@K20 Engine Control Module
- Test for infinite resistance between the test points: 5 V Reference 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
- Test for less than 2 ohms between the test points: 5 V Reference circuit terminal 1@Component harness & Terminal 39@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
- Ignition/Vehicle - Off
- Disconnect the electrical connector: X3@K20 Engine Control Module
- Ignition - On/Vehicle - In Service Mode
- Test for less than 1 V between the test points: 5 V Reference 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
NOTE:Internal control module or component damage may occur if the circuit shorts to B+.
- Go to next step: If between 4.8 and 5.2 V
- Verify the scan tool parameter: Fuel Pressure Sensor = Less than 0.2 V
- If 0.2 V or greater
- Ignition/Vehicle - Off
- Disconnect the electrical connector: X3@K20 Engine Control Module
- Ignition - On/Vehicle - In Service Mode
- Test for less than 1 V between the test points: Signal 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 less than 0.2 V
- Connect a 3 A fused jumper wire between the test points: Signal circuit terminal 3 & 5 V Reference circuit terminal 1
- Verify the scan tool parameter: Fuel Pressure Sensor = Greater than 4.8 V
- If 4.8 V or less
- Ignition/Vehicle - Off & Remove - Jumper wire(s)
- Disconnect the electrical connector: X3@K20 Engine Control Module
- Test for infinite resistance between the test points: Signal 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
- Test for less than 2 ohms between the test points: Signal circuit terminal 3@Component harness & Terminal 59@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: B47 Fuel Pressure Sensor