Circuit/System Testing

Test 1

1. Ignition/Vehicle - Off
NOTE:
• For detailed component terminal information, refer to: Engine Controls Wiring Schematics
• This procedure uses the following circuit names:
  • Voltage Control = Control circuit terminal 1@Q17 Fuel Injector
  • Voltage Supply = Control circuit terminal 2@Q17 Fuel Injector
• Perform this diagnostic for the component that set the DTC.
2. Disconnect the appropriate electrical connector: K20 Engine Control Module
3. Test for infinite resistance between the test points: Voltage Supply & Ground
   • If less than infinite resistance 
   1. Disconnect the appropriate electrical connector: Q17 Fuel Injector
   2. Test for infinite resistance between the test points: Voltage Supply @ Control module harness & Ground
      • If less than infinite resistance - Repair the short to ground on the circuit.
      • Go to next step: If infinite resistance
   3. Test for infinite resistance between the test points: Voltage Control @ Control module harness & Ground
      • If less than infinite resistance - Repair the short to ground on the circuit.
      • If infinite resistance - Test or replace the component: Q17 Fuel Injector
   • Go to next step: If infinite resistance 
4. Ignition - On/Vehicle - In Service Mode
5. Test for less than 1 V between the test points: Voltage Supply @ Control module harness & Ground
   • If 1 V or greater 
   1. Disconnect the appropriate electrical connector: Q17 Fuel Injector
   2. Test for less than 1 V between the test points: Voltage Supply @ Control module harness & Ground
      • If 1 V or greater - Repair the short to voltage on the circuit.
      • If less than 1 V - Repair the short to voltage on the circuit: Voltage Control
   • Go to next step: If less than 1 V 
6. Ignition/Vehicle - Off
7. Test for less than 3 ohms between the test points: Voltage Supply & Voltage Control@ Control module harness
   • If 3 ohms or greater 
   1. Disconnect the appropriate electrical connector: Q17 Fuel Injector
   2. Test for less than 2 ohms between the test points:
      • Voltage Control @ Control module harness & The other end of the circuit@Component harness
      • Voltage Supply @ Control module harness & The other end of the circuit@Component harness
      • If 2 ohms or greater - Repair the open/high resistance in the circuit.
      • If less than 2 ohms - Test or replace the component: Q17 Fuel Injector
   • Go to next step: If less than 3 ohms 
8. Replace the component: K20 Engine Control Module

Test 2

1. Ignition/Vehicle - Off
NOTE:
• For detailed component terminal information, refer to: Engine Controls Wiring Schematics
• This procedure uses the following circuit names:
  • Voltage Control = Control circuit terminal 1@Q17 Fuel Injector
  • Voltage Supply = Control circuit terminal 2@Q17 Fuel Injector
• Perform this diagnostic for the component that set the DTC.
2. Disconnect the appropriate electrical connector: K20 Engine Control Module
3. Test for infinite resistance between the test points: Voltage Supply & Ground
   • If less than infinite resistance 
   1. Disconnect the appropriate electrical connector: Q17 Fuel Injector
   2. Test for infinite resistance between the test points: Voltage Supply @ Control module harness & Ground
      • If less than infinite resistance - Repair the short to ground on the circuit.
      • Go to next step: If infinite resistance
   3. Test for infinite resistance between the test points: Voltage Control @ Control module harness & Ground
      • If less than infinite resistance - Repair the short to ground on the circuit.
      • If infinite resistance - Test or replace the component: Q17 Fuel Injector
   • Go to next step: If infinite resistance 
4. Ignition - On/Vehicle - In Service Mode
5. Test for less than 1 V between the test points: Voltage Supply @ Control module harness & Ground
   • If 1 V or greater 
   1. Disconnect the appropriate electrical connector: Q17 Fuel Injector
   2. Test for less than 1 V between the test points: Voltage Supply @ Control module harness & Ground
      • If 1 V or greater - Repair the short to voltage on the circuit.
      • If less than 1 V - Repair the short to voltage on the circuit: Voltage Control
   • Go to next step: If less than 1 V 
6. Ignition/Vehicle - Off
7. Disconnect the appropriate electrical connector: Q17 Fuel Injector
8. Test for less than 2 ohms between the test points:
   • Voltage Control @ Control module harness & The other end of the circuit@Component harness
   • Voltage Supply @ Control module harness & The other end of the circuit@Component harness
   • If 2 ohms or greater 

     Repair the open/high resistance in the circuit.

   • Go to next step: If less than 2 ohms 
9. Test for infinite resistance between the test points: Voltage Control & Voltage Supply@Component harness
   • If less than infinite resistance 

     Repair the short between the circuits.

   • Go to next step: If infinite resistance 
10. Perform the following procedure/test: Component Testing

    Verify the procedure/test passes.

    • If the procedure/test does not pass 

      Replace the component: Q17 Fuel Injector

    • Go to next step: If the procedure/test passes 
11. Replace the component: K20 Engine Control Module

Test 3

1. Ignition/Vehicle - Off
2. Disconnect the appropriate electrical connector: K20 Engine Control Module
3. Disconnect the appropriate electrical connector: Q17 Fuel Injector
4. Test for infinite resistance between the test points: Control circuit terminal 1 & Control circuit terminal 2@Component harness
   • If less than infinite resistance 

     Repair the short between the circuits.

   • Go to next step: If infinite resistance 
5. Perform the following procedure/test: Component Testing

   Verify the procedure/test passes.

   • If the procedure/test does not pass 

     Replace the component: Q17 Fuel Injector

   • Go to next step: If the procedure/test passes 
6. Replace the component: K20 Engine Control Module