Have you ever wondered how safe from electrical shock are you in an electric vehicle? Watch as I create direct high voltage shorts to the vehicle chassis, shorts through conductive liquids, and how the vehicle detects these short circuits. A 2017 Chevrolet Bolt EV is used as an example vehicle. Timeline:
Introduction at 0:07
Safety Warning at 0:25
High Voltage (HV) Insulation/Isolation example at 0:40
On-Car high voltage power distribution at 2:50
Live HV measurements (Car Powered Off) at 4:55
Live HV measurements (Car Powered On) at 6:15
MUST SEE: Shorting the 381V battery positive cable to vehicle chassis at 7:36
Which Diagnostic Trouble Codes (DTC)s were set at 9:57
MUST SEE: Shorting the 381V battery negative cable to vehicle chassis at 11:18
What can happen in an automobile accident at 13:25
MUST SEE: How loss of isolation can occur through conductive liquids at 13:50
How the car performs active isolation testing and passive isolation testing at 14:41
Normal passive scan tool data values for loss of isolation detection at 16:10
See the results of an 11 Million ohm connection to vehicle chassis at 18:30
See the results of a 4.65 Million ohm connection to vehicle chassis at 20:50
See the results of a 1.16 Million ohm connection to vehicle chassis at 22:20
See the results of a 551 thousand ohm connection to vehicle chassis at 23:00
See the results of a 222 thousand ohm connection to vehicle chassis at 23:35
MUST SEE: The 318-265 k ohm threshold to trigger a loss of isolation DTC at 23:40
MUST SEE: GM On-Star notification of battery problem at 24:50
See the results of a 110 thousand ohm connection to vehicle chassis at 25:15
MUST SEE: See the results of a 0 (zero) ohm connection to vehicle chassis at 25:51
See my voltage drop measurement table at 26:54
MUST SEE: See the results of a conductive liquid connection to vehicle chassis at 27:35
How to determine the location of a loss of isolation problem at 30:00
Clearing Secured High Voltage DTCs with a GM GDS2 scan tool at 32:08
Hybrid/EV battery pack active isolation test at 33:00
Hybrid/EV battery pack heater passive isolation test at 34:35
The Megohmeter and the factory specifications for isolation resistance at 37:28
Example of using the Fluke 1587 Insulation Tester (Megohmeter) at 40:30
Video summary at 44:05
Weber State University (WSU) - Department of Automotive Technology - Ardell Brown Technology Wing - Transmission Lab.
This episode covers what happens with the high voltage system looses isolation with the vehicle chassis of an electric vehicle (EV), plug-in electric vehicle (PHEV), or hybrid electric vehicle (HEV). A 2017 Chevrolet Bolt EV is used as an example vehicle in this video.
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This video was created and edited by Professor John D. Kelly at WSU. For a full biography, see
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