Tesla Model 3: HV Battery Contactor Seize Check

SPECIAL TOOLS

Insulation Multimeter Fluke 1587 FC (1076921-00-A)

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.

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 multimeter and leads are capable of handling at least 500V DC.

Procedure

1. Remove the penthouse cover. See Cover - Penthouse (Remove and Replace).
2. Set the insulation multimeter to measure resistance, and touch the probe tips together.

Caution:

If the multimeter displays greater than 0.2 ohms, the leads are defective and must be replaced. Do not use defective leads.

3. Consider your next step:

• If the positive contactor is suspect to have seized, go to step 4.
• If the negative contactor is suspect to have seized, go to step 9.
• If both contactors are suspect, or there is uncertainty, start with step 4.

4. Inspect the center of the insulator caps on top of the HV battery positive contactor terminals:

• If the insulator caps have a probing hole, continue to step 5.
• If the insulator caps are solid, remove the insulator caps and continue to step 5.

5. Set the multimeter to measure the DC voltage across both terminals of the HV battery positive contactor, either through the probing hole of the insulator caps or directly onto the terminals:
6. If the measured voltage is outside the range of -0.1V to 0.1V, then the HV battery positive contactor is not seized. Continue to step 6.

Caution:  Do not make the resistance measurement below because it could damage the multimeter.

• If the measured voltage is between -0.1V and 0.1V, set the multimeter to measure resistance and measure the resistance across the HV battery positive contactor terminals:

• If the measured resistance is greater than 1M Ohm (1000K Ohm), then the HV battery positive contactor is not seized. Proceed to step 6.
• If the measured resistance is lower than 1M Ohm, then the HV battery positive contactor might be seized. Discontinue this procedure and replace the HV battery positive contactor. See Contactor - Positive - HV Battery (Remove and Replace), and then retest.

6. Set the multimeter to measure resistance, and then perform the following measurements:

7. Reinstall the HV battery positive contactor insulator caps, if they were removed earlier.
8. If the HV battery negative contactor is also suspect to have seized, or there is uncertainty, go to step 9. Otherwise, return to the Vehicle Electrical Isolation Procedure.

9. Inspect the center of the insulator caps on top of the HV battery negative contactor terminals:

• If the insulator caps have a probing hole at the center, continue to step 10.
• If the insulator caps are solid, remove the insulator caps and continue to step 10.

10. Set the multimeter to measure the DC voltage across both terminals of the HV battery negative contactor, either through the probing hole of the insulator caps or directly onto the terminals:

• If the measured voltage is outside the range of -0.1V to 0.1V, then the HV battery negative contactor is not seized. Continue to step 11.

Caution: Do not make the resistance measurement below because it could damage the multimeter.

• If the measured voltage is between -0.1V and 0.1V, set the multimeter to measure resistance and measure the resistance across the HV battery negative contactor terminals:

• If the measured resistance is greater than 1M Ohm (1000K Ohm), then the HV battery negative contactor is not seized. Proceed to step 11.
• If the measured resistance is lower than 1M Ohm, then the HV battery negative contactor might be seized. Discontinue this procedure and replace the HV battery negative contactor. See Contactor - Negative - HV Battery (Remove and Replace), and then retest.

Set the multimeter to measure resistance, and then perform the following measurements:

12. Reinstall the HV battery negative contactor insulator caps, if they were removed earlier.
13. Return to the Vehicle Electrical Isolation Procedure.

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