December/January 2022

34 AFTERMARKET DECEMBER/JANUARY 2022 TECHNICAL/SNAP-ON www.aftermarketonline.net Fig.1 Fig.2 Fig.3 Fig.4 Fig.5 Fig.6 displayed the correct voltage of each battery block. Please refer to Fig.8, which shows the voltage for four battery blocks under hard acceleration. This results in a noticeable voltage drop on each block. All fourteen blocks should return a similar voltage under all conditions; Full electric mode, hard acceleration and regenerative braking. Next, refer to Fig.9, which shows the voltage for four battery blocks under regenerative braking. This results in voltage increase on each block. The Prius information display shows the driver the current driving mode through the energy monitor, which is helpful for fault finding. Fig.10 shows a vehicle stationary with engine off. Fig.11 shows normal driving with the CE operating. Fig.12 shows the vehicle operating in full electric mode. Fig.13 shows the high voltage battery being charged through regenerative braking. Conditions While road-testing the vehicle we can check the condition of the high voltage battery under certain operating conditions. Fig.14 and Fig.15 show the impact of regenerative braking. Fig.16 and Fig.17 shows what happens in EV mode. During this test we are looking for a difference of no greater than 0.3 volts between any of the battery blocks under load. Fig.18 show the relationship between current and voltage under regenerative braking, while Fig.19 shows the same relationship when the vehicle is in EV mode. After road-testing the vehicle and carrying out a post scan with the diagnostic tool, the vehicle was returned to the customer. www.aftermarketonline.net Each battery block has a sensing wire attached to a negative stud ”