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Circuit/System Testing

    WARNING:

    Always perform the High Voltage Disabling procedure prior to servicing any High Voltage component or connection. Personal Protection Equipment (PPE) and proper procedures must be followed.

    The High Voltage Disabling procedure will perform the following tasks:

    • Identify how to disable high voltage.
    • Identify how to test for the presence of high voltage.
    • Identify condition under which high voltage is always present and personal protection equipment (PPE) and proper procedures must be followed.

    Failure to follow the procedures exactly as written may result in serious injury or death.

  1. Disable the high voltage for servicing at the A4 Battery Pack, K1 14V Power Module and the T18 Battery Charger. Refer to High Voltage Disabling .
  2. Disconnect the X3 connector at the T18 Battery Charger, the X4 connector at the K1 14V Power Module, the X153 inline connector, and the X367 connector at the A4 Battery Pack.
  3. Verify that all HV harness connector and mating module connector terminals are free from moisture, corrosion and arc flash damage.
    • If any terminals show signs of damage 

      Replace the HV wiring harness and effected modules as necessary.

    • Go to next step: If no arc flash damage, moisture, or corrosion is found 
  4. Reconnect the inline high voltage harness connector X153.
  5. Test the following HV harness terminals for less than 2 Ω end to end:
    • X367-A to X3-1
    • X367-A to X4-B
    • X367-B to X3-2
    • X367-B to X4-A
    • If 2 Ω or greater 

      Replace the HV wiring harness.

    • Go to next step: If less than 2 Ω 
    6. NOTE:

    This test is performed at the module terminals with the test measurement initially several Meg ohms and slowly decreasing to a minimal value.

  6. Test the K1 14 V Power Module X4 terminals for greater than 10K Ω, X4-A to X4-B.
    • If 10K Ω or less 

      Replace the K1 14V Power Module and the A28 Hybrid/EV Battery Contactor Assembly.

    • Go to next step: If greater than 10 K Ω 
    7. NOTE:

    This test is performed at the module terminals with the test measurement initially several Meg ohms and slowly decreasing to a minimal value.

  7. Test the T18 Battery Charger terminals for greater than 10K Ω, X3-1 to X3-2.
    • If 10K Ω or less 

      Replace the T18 Battery Charger and the A28 Hybrid/EV Battery Contactor Assembly.

    • Go to next step: If greater than 10 K Ω 
  8. Replace the T18 Battery Charger, reassemble the vehicle, clear DTCs and repeat Circuit/System Verification.
    • If Circuit/System Verification is not OK 

      Replace the A28 Hybrid/EV Battery Contactor Assembly.

    • Go to next step: If Circuit/System Verification is OK 
  9. All OK.
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