FixVault

Circuit/System Testing

  1. Ignition ON, with a scan tool verify the Run/Crank Terminal status is ACTIVE.
    • If not the specified value, test the ECM ignition circuit listed below for a short to ground or an open/high resistance. If the circuit tests normal, replace the K20 Engine Control Module.
  2. Ignition OFF, disconnect the KR27 Starter Relay.
  3. Ignition OFF and scan tool disconnected, open and close the driver door, and wait 1 min. Test for less than 5 Ω between the relay ground circuit terminal 85 and ground.
    • If greater than the specified range, test the ground circuit for an open/high resistance.
  4. Ignition ON, verify a test lamp illuminates between the B+ circuit terminal 30 and ground.
    • If the test lamp does not illuminate, test the B+ circuit for a short to ground or an open/high resistance. If the circuit tests normal and the B+ circuit fuse is open, test the control circuit terminal 87 for a short to ground.
  5. Ignition ON, verify that a test lamp does not illuminate between the control circuit terminal 87 and ground.
    • If the test lamp illuminates, test the control circuit for a short to voltage.
  6. Ensure the parking brake is applied and the transmission is in NEUTRAL on manual transmission or PARK on automatic transmissions. Momentarily install a 40 A fused jumper wire between the B+ circuit terminal 30 and the control circuit terminal 87. Verify the starter is activated.
    • If the starter does not activate, test the control circuit for a short to ground or an open/high resistance. If the circuit tests normal, test or replace the starter.
  7. Connect a test lamp between the control circuit terminal 85 and the ground circuit terminal 86.
  8. With the transmission range selector in park/neutral, or the clutch pedal fully applied, place the ignition switch between the OFF and CRANK position. The test lamp should turn ON and OFF when changing between the commanded states.
    • If the test lamp is always ON, test the control circuit for a short to voltage. If the circuit tests normal, replace the K20 Engine Control Module.
    • If the test lamp is always OFF, test the control circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the K20 Engine Control Module.
  9. If all circuits test normal, test or replace the KR27 Starter Relay.