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Circuit/System Testing - T19 Multifunction Power Supply Converter Input/Output Circuit Test

NOTE:

Circuit/System Verification must be performed before proceeding with Circuit/System Testing.

    NOTE:

    Do not replace the T19 Power Supply control module if you cannot reproduce the codes during a drive cycle.

  1. Ignition Off, disconnect the connector at the T19 Multifunction Power Supply Converter.
  2. Verify a test lamp illuminates between ground circuit terminal 7 and B+.
    • If the test lamp does not illuminate 

      Repair the open/high resistance on circuit 250 or the ground connection.

    • Go to next step: If the test lamp illuminates 
  3. Verify a test lamp illuminates between ground circuit terminal 12 and B+.
    • If the test lamp does not illuminate 

      Repair the open/high resistance on circuit 250 or the ground connection.

    • Go to next step: If the test lamp illuminates 
  4. Verify a test lamp illuminates between B+ circuit terminal 11 and ground.
    • If the test lamp does not illuminate and the circuit fuse is good 
    1. Test circuit 8040 for an open/high resistance.
      • if an open/high resistance is found, repair the fault on the circuit.
      • Go to next step: If an open or high resistance is not found
    2. Verify the fuse is not open and there is voltage at the fuse.
    • If the test lamp does not illuminate and the circuit fuse is open 
    1. Test circuit 8040 for a short to ground
      • If a short to ground is found, repair the fault on the circuit.
      • Go to next step: If a short to ground is not found
    2. Test circuit 2172 for a short to ground
      • If a short to ground is found, repair the fault on the circuit.
      • Go to next step: If a short to ground is not found
    3. Replace the T19 Multifunction Power Supply Converter.
    • Go to next step: If the test lamp illuminates 
  5. Ignition On vehicle in Service mode.
  6. Verify a test lamp does not turn on between control circuit terminal 10 and ground.
    • If the test lamp turns on 

      Repair the short to voltage on circuit 2172.

    • Go to next step: if the test lamp does not turn on 
  7. Remove all appropriate fuses supplied by circuit 2172.
  8. Test for infinite resistance between Terminal 10 at the T19 Multifunction Power Supply Converter and ground.
    • If less than infinite resistance 

      Repair the short to ground on circuit 2172.

    • Go to next step: If infinite resistance 
  9. Connect all connectors.
  10. Clear all DTCs.
  11. Road test the vehicle allowing a minimum of 5 engine auto stop/start events to occur.
  12. Verify DTC P3051, P3053, or P3055 did not reset.
    • If any of the DTCs reset 
    1. Verify the Ignition circuit 439 at the K20 Engine Control Module is within 1 V of control circuit 2172 at the T19 Multifunction Power Supply Converter.
      • if not within the specified value 

        Repair the open/high resistance in circuit 439.

      • Go to next step: If within the specified value 
    2. Replace the T19 Multifunction Power Supply Converter.
    • Go to next step: If any of the DTCs did not reset 
  13. A fault is not currently present and may be an intermittent condition.
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