Circuit/System Testing

WARNING: This page is about a different car, the 2019 Chevrolet Malibu. However, it is still accessible from the selected car via links, so may be relevant.

Ignition/Vehicle - Off
Disconnect the electrical connector: G18 High Pressure Fuel Pump
Connect a test lamp between the test points: Control circuit terminal 1 & Control circuit terminal 2
Ignition - On / Vehicle - In Service Mode
Perform the scan tool control function: Fuel Pressure Regulator - On and Off
Verify the test lamp turns On and Off.
- If the test lamp does not turn On and Off
1. Ignition/Vehicle - Off & Remove - Test lamp
2. Disconnect the electrical connector: X3 @ K20 Engine Control Module
3. Ignition - On / Vehicle - In Service Mode
4. Test for less than 1 V between the test points:
  - Control circuit terminal 1 @ Component harness & Ground
  - Control circuit terminal 2 @ Component harness & Ground
  - If 1 V or greater - Repair the short to voltage on the circuit.
  - Go to next step: If less than 1 V
5. Ignition/Vehicle - Off
6. Test for infinite resistance between the test points:
  - Control circuit terminal 1 @ Component harness & Ground
  - Control circuit terminal 2 @ Component harness & Ground
  - If less than infinite resistance - Repair the short to ground on the circuit.
  - Go to next step: If infinite resistance
7. Test for less than 2 ohms between the test points:
  - Control circuit terminal 1 @ Component harness & Terminal 72 @ Control module harness
  - Control circuit terminal 2 @ Component harness & Terminal 52 @ 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 the test lamp turns On and Off
Test or replace the component: G18 High Pressure Fuel Pump