After seeing so many post from people here wanting to have cruise control in
their Prius, I felt guilty having installed cruise control in my Prius and not
sharing the information with anyone. So I decided to come out of lurk mode and
briefly describe how cruise control can be installed in a Prius.

I would first like to mention that this is something someone who is reasonably
competent and possesses the service manuals could easily do themselves. I would
recommend, however, to have this done by the dealer, considering that it should
take less than an hour and that they have the proper tools. Also considering the
cost of the parts, the dealer labor costs are negligible.

Let me quickly explain what is already in place in the Prius for cruise control:
The wiring is already in place along with the ECU that controls the cruise
functions and the instrument "CRUISE CONTROL" light is in place.

What is not present is obviously the cruise control switch. The existing brake
switch, which has one contact, also needs to be replaced with one that has two
contacts.

The brake switch can be replaced rather easily. The cruise control switch could
in theory be installed rather easily too if it weren't for the fact that the
plastic housing of the steering wheel has no mounting places or cutouts for the
new switch. Unfortunately, a new plastic housing with the proper cutouts and
mounting locations is currently not available from Toyota. You will have to buy
a complete new cruise control steering wheel (minus the airbag). The parts
breakdown shows the cruise control stalk as a separate part, but it actually
comes mounted with the cruise control steering wheel (at least it did on mine).

So installation of the cruise control amounts to replacing the brake switch and
steering wheel. The steering wheel is held in place with a nut and is splined
and press fitted. A special tool described in the service manual is used to
remove the steering wheel.

The parts needed for this are

NAME Part # Price
-------------------- --------------- -----
Stop Switch assembly 84340-32070 $46
Steering wheel assembly 45100-47020-B0 $600
Plastic insert for SW 45187-30060-B3 $3

These are the same parts which are used in a Prius with cruise control. The
plastic insert for SW is a rectangular piece of plastic which covers a hole on
the left side of the steering wheel. In case you wanted to know, the cruise
control switch is part #84630-47010 for $131, but you won't need this since it's
included with the steering wheel.

Currently this is a very costly option. If Toyota where to offer the steering
wheel housing separately along with a rubber boot for the cruise control stalk,
the parts cost should be well under $300.

I hope this helps,

Alex Karahalios