LEMON Manuals: Even more car manuals for everyone: 1960-2025
Home >> Cadillac >> 2018 >> CT6 Plug-In >> Repair and Diagnosis >> Electrical >> Body Electrical >> Plug-In Charging >> Diagnostic Information and Procedures >> Plug-In Charging Malfunction >> Circuit/System Testing
April 5, 2026: LEMON Manuals is launched! Read the announcement.

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 includes the following steps:

  • 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.

Before working on any high voltage system, be sure to wear the following Personal Protection Equipment:

  • Safety glasses with appropriate side shields when within 15 meters (50 feet) of the vehicle, either indoors or outdoors.
  • Certified and up-to-date Class "0" Insulation gloves rated at 1000V with leather protectors.
    • Visually and functionally inspect the gloves before use.
    • Wear the Insulation gloves with leather protectors at all times when working with the high voltage battery assembly, whether the system is energized or not.

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

  1. Connect the customer's drive motor battery charger cable to household power outlet, but not the vehicle battery charger receptacle.
  2. After 25 seconds, verify drive motor battery charger cable AC Present Indicator illuminates solid green.
    • If drive motor battery charger cable AC Present Indicator does not illuminate solid green 
    1. Connect a known good drive motor battery charger cable to the same household power outlet.
      • If known good drive motor battery charger cable AC Present Indicator illuminates solid green, replace the customer's drive motor battery charger cable.
      • If known good drive motor battery charger cable AC Present Indicator does not illuminate solid green, have the service provider inspect the household power outlet for insufficient voltage, high frequency noise, or open/high resistance.
    • Go to next step: If drive motor battery charger cable AC Present Indicator does illuminate solid green 
  3. GM4177682Courtesy of GENERAL MOTORS COMPANY

    Test for greater than 1 V between the low voltage circuits listed below on drive motor battery charger cable.

    • Proximity status signal circuit terminal 5
    • Control pilot signal circuit terminal 2
    • If less than 1 V 

      Replace drive motor battery charger cable.

    • Go to next step: If greater than 1 V 
  4. GM4177681Courtesy of GENERAL MOTORS COMPANY
    NOTE:

    The following tests are performed at the X98 Hybrid/EV Battery Charger Receptacle face and not at the harness connector to the X98 Hybrid/EV Battery Charger Receptacle.

    NOTE:

    When measuring resistance observe proper meter polarity by connecting the common/ground meter probe to ground/vehicle chassis.

    NOTE:

    You must measure with a high-impedance Digital Multimeter (DMM) such as the EL-39200 or equivalent.

    Vehicle OFF and all vehicle systems OFF. It may take up to 2 minutes for all vehicle systems to power down. Test for 100k Ω - 4M Ω between the control pilot signal terminal 2 at the X98 Hybrid/EV Battery Charger Receptacle and ground.

    • If 4M Ω or greater 
    1. Disconnect the X2 harness connector from K114B Hybrid/EV Powertrain Control Module 2
    2. Test for 2 Ω in the control pilot signal circuit end to end.
      • If 2 Ω or greater, repair the open/high resistance in the circuit.
      • If less than 2 Ω, replace the K114B Hybrid/EV Powertrain Control Module 2.
    • If less than 100k Ω 
    1. Disconnect the X2 harness connector from K114B Hybrid/EV Powertrain Control Module 2
    2. Test for infinite resistance between the control pilot signal circuit and ground.
      • If less than infinite resistance, repair the short to ground in the circuit.
      • If infinite resistance, replace the K114B Hybrid/EV Powertrain Control Module 2.
    • Go to next step: If within the specified range 
  5. GM4177681Courtesy of GENERAL MOTORS COMPANY

    Test for less than 1 V between the control pilot signal terminal 2 at the X98 Hybrid/EV Battery Charger Receptacle and ground.

    • If greater than 1 V 
    1. Disconnect the X2 harness connector from K114B Hybrid/EV Powertrain Control Module 2
    2. Test for less than 1 V between the control pilot signal circuit and ground.
      • If greater than 1 V, repair the short to voltage in the circuit.
      • If less than 1 V, replace the K114B Hybrid/EV Powertrain Control Module 2.
    • Go to next step: If less than 1 V 
  6. Vehicle in Service Mode.
  7. GM4177681Courtesy of GENERAL MOTORS COMPANY

    Test for 4.2 - 5.2 V between the proximity status signal terminal 5 at the X98 Hybrid/EV Battery Charger Receptacle and ground.

    • If less than 4.2 V 
    1. Vehicle OFF, test for infinite resistance between the proximity status signal circuit and ground.
      • If less than infinite resistance, repair the short to ground on the circuit.
      • Go to next step: If infinite resistance
    2. Disconnect the X2 harness connector from K114B Hybrid/EV Powertrain Control Module 2.
    3. Test for less than 2 Ω in the proximity status signal circuit end to end.
      • If 2 Ω or greater, repair the open/high resistance in the circuit.
      • If less than 2 Ω, replace the K114B Hybrid/EV Powertrain Control Module 2.
    • If greater than 5.2 V 
    1. Disconnect the X2 harness connector from K114B Hybrid/EV Powertrain Control Module 2
    2. Test for 0 V between the proximity status signal circuit and ground.
      • If greater than 0 V, repair the short to voltage in the circuit.
      • If 0 V, replace the K114B Hybrid/EV Powertrain Control Module 2.
    • Go to next step: If within the specified range 
  8. Vehicle OFF and all vehicle systems OFF. It may take up to 2 minutes for all vehicle systems to power down. Disconnect the X2 harness connector from T18 Battery Charger and the X2 harness connector from the K114B Hybrid/EV Powertrain Control Module 2.
  9. GM4177681Courtesy of GENERAL MOTORS COMPANY

    Test for infinite resistance between the terminals listed below at the X98 Hybrid/EV Battery Charger Receptacle:

    • Voltage AC Line 1 terminal 3 and Voltage AC Neutral Line 2 terminal 4
    • Voltage AC Line 1 terminal 3 and Voltage AC Ground terminal 1
    • Voltage AC Line 1 terminal 3 and Control pilot signal circuit terminal 2
    • Voltage AC Line 1 terminal 3 and Proximity status signal circuit terminal 5
    • Voltage AC Neutral Line 2 terminal 4 and Voltage AC Ground terminal 1
    • Voltage AC Neutral Line 2 terminal 4 and Control pilot signal circuit terminal 2
    • Voltage AC Neutral Line 2 terminal 4 and Proximity status signal circuit terminal 5
    • Voltage AC Ground terminal 1 and Control pilot signal circuit terminal 2
    • Control pilot signal circuit terminal 2 and Proximity status signal circuit terminal 5
      • If less than infinite resistance 

        Repair the short between the circuits.

    • Go to next step: If infinite resistance 
  10. Disconnect the harness connector from the X98 Hybrid/EV Battery Charger Receptacle.
  11. GM4177681Courtesy of GENERAL MOTORS COMPANY

    Test for 2.56 - 2.84k Ω between the Voltage AC Ground terminal 1 and Proximity status signal circuit terminal 5 at the X98 Hybrid/EV Battery Charger Receptacle face.

    • If not within the specified range 

      Replace the X98 Hybrid/EV Battery Charger Receptacle.

    • Go to next step: If within the specified range 
    12. NOTE:

    This test is performed on the vehicle side of the harness connector.

  12. Test for infinite resistance between the Voltage AC Ground terminal 1 and Proximity status signal circuit terminal 5 of the harness connector.
    • If less than infinite resistance 

      Repair the short between the circuits.

    • Go to next step: If infinite resistance 
  13. Replace and program the K114B Hybrid/EV Powertrain Control Module 2.
  14. Repeat Circuit/System Verification and confirm vehicle is All OK.
    • If Circuit/System Verification was not All OK 

      Replace the T18 Battery Charger.

    • Go to next step: If Circuit/System Verification was All OK 
  15. All OK.
scientia non olet · About LEMON Manuals