Vehicle Electrical Isolation Procedure

Correction code 1701000017010000
  • 1076921-00-B Insulation Multimeter, Fluke 1507
  • 1130480-00-A Test Probes, Slim, Fluke TP38

SPECIAL TOOLS

Insulation Multimeter, Fluke 1507 (1076921-00-B)
Test Probes, Slim, Fluke TP38 (1130480-00-A)
Warning: This procedure verifies that high voltage power is no longer available to high voltage components (PTC heater, A/C compressor, inverters, etc). Perform this procedure before servicing high voltage components.
Warning: Remove all jewelry (watches, bracelets, rings, necklaces, earrings, ID tags, piercings, etc.) from your person, and all objects (keys, coins, pens, pencils, tools, fasteners, etc.) from your pockets before performing any procedure that exposes you to high voltage.
Warning: If corrective eyewear is necessary to safely perform any procedure, make sure that the eyewear is securely restrained to the head and cannot fall off.
Warning:

Only technicians who have been trained in High Voltage Awareness are permitted to perform this procedure. Proper personal protective equipment (PPE) and insulating HV gloves with a minimum rating of class 0 (1000V) must be worn at all times a high voltage cable, busbar, or fitting is handled. Refer to Tech Note TN-15-92-003, "High Voltage Awareness Care Points" for additional safety information.

Warning: Make sure that the insulation meter and leads are capable of handling at least 500V DC.
Parent topic: 1701 - 12V Battery and Fuses

Procedure

  1. Disconnect 12V power. See 12V Power (Disconnect and Connect).
  2. Set the insulation multimeter to measure the voltage across the 12V auxiliary battery terminals.
    Caution:
    If the voltage across the 12V auxiliary battery terminals is less than 10 volts or greater than 14 volts, the multimeter is not measuring reliably and must not be used. Use only a fully functional insulation multimeter.
  3. Remove all jewelry and empty your pockets before continuing this procedure.
  4. Put on HV insulating gloves and leather outer gloves before continuing this procedure.
  5. Remove the HV probe cover. See Cover - HV Probe - HV Battery (Remove and Replace).
  6. Use the insulation multimeter to probe the voltages.

    Component Test

    B+

    (LH probe opening)

    B-

    (RH probe opening)

    GND

    Measured Voltage Less Than 10 V

    Measured Voltage 10 V Or More

    HV

    Positive (+) Lead

    Negative (-) Lead

    		  

    Pass

    Fail

    Perform a HV battery contactor seize check. See HV Battery Contactor Seize Check.

    HV battery positive contactor

    Positive (+) Lead

    		  

    Negative (-) Lead

    Pass

    Fail

    HV battery positive contactor might be seized. See HV Battery Contactor Seize Check.

    HV battery negative contactor

    		  

    Positive (+) Lead

    Negative (-) Lead

    Pass

    Fail

    HV battery negative contactor might be seized. See HV Battery Contactor Seize Check.
  7. Install the HV probe cover. See Cover - HV Probe - HV Battery (Remove and Replace).
  8. Return to the procedure that required the vehicle to be electrically isolated.
    Note: After finishing the procedure that required the vehicle to be electrically isolated, perform a penthouse air leak test. See Penthouse Air Leak Test.
1Disconnect 12V power. See 12V Power (Disconnect and Connect).
2Set the insulation multimeter to measure the voltage across the 12V auxiliary battery terminals.
Caution:
If the voltage across the 12V auxiliary battery terminals is less than 10 volts or greater than 14 volts, the multimeter is not measuring reliably and must not be used. Use only a fully functional insulation multimeter.
3Remove all jewelry and empty your pockets before continuing this procedure.
4Put on HV insulating gloves and leather outer gloves before continuing this procedure.
5Remove the HV probe cover. See Cover - HV Probe - HV Battery (Remove and Replace).
6Use the insulation multimeter to probe the voltages.

Component Test

B+

(LH probe opening)

B-

(RH probe opening)

GND

Measured Voltage Less Than 10 V

Measured Voltage 10 V Or More

HV

Positive (+) Lead

Negative (-) Lead

  

Pass

Fail

Perform a HV battery contactor seize check. See HV Battery Contactor Seize Check.

HV battery positive contactor

Positive (+) Lead

  

Negative (-) Lead

Pass

Fail

HV battery positive contactor might be seized. See HV Battery Contactor Seize Check.

HV battery negative contactor

  

Positive (+) Lead

Negative (-) Lead

Pass

Fail

HV battery negative contactor might be seized. See HV Battery Contactor Seize Check.
7Install the HV probe cover. See Cover - HV Probe - HV Battery (Remove and Replace).
8Return to the procedure that required the vehicle to be electrically isolated.
Note: After finishing the procedure that required the vehicle to be electrically isolated, perform a penthouse air leak test. See Penthouse Air Leak Test.