The Prius That Shook.. - VFAQ Prius Site

engine noise is present at all times while the car is moving
while driving. However, in a hybrid vehicle, the engine stops
when the car is driven in EV mode or when waiting at a
traffic light. The clicking noise of the relay is quite obvious
when the car engine is silent.
However, when this problem was pointed out,
development was at the final stage, and design changes would
have been impossible. Rather than try to deal with the
problem at the assembly stage, it was a better idea to modify
the part itself, even though that would be more costly. Oi
decided to wrap the relay in sound-insulating material as
the final solution.
Unfortunately, the assembly processes were already rigidly
set at the Takaoka Plant, and it was impossible to add the new
process of wrapping the relay. Oi then asked Denso, the
manufacturer of this relay, to wrap the relay before shipment.
At this point, both the new car presentation and Tokyo
Motor Show were over, and the next major event was the
launch of Prius. This improvement was made at the very last
moment.
During these days, Oi was making a three-point
commute every day from his home in Nagoya to the Head
Office to Takaoka Plant to his home. He frequently came
home after four in the morning.
Some parts were unique to the hybrid vehicle, and
Toyota was buying parts for the first time from certain
suppliers. It was necessary that these new suppliers understand
Toyota's design philosophy from the beginning
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