Most people who install the cruise control themselves are either technically
or mechanically inclined. If you are not comfortable working on cars,
we recommend you use a professional installer. Please e-mail
us if you need one, and we'll find one in your area.
These comments are from three customers, Clifford
Flath, Neil Adler and Ethan
Upper, based on their experiences installing the Rostra cruise control
in their Scions. The comments reflect their opinions, and not that of
Allscion or Rostra.
Clifford Flath's installation remarks
Should not instruct to remove the grommet. It doesn't help to remove
it, and it's terrible to get back in. It should also say that the grommet
has an outer membrane and an inner membrane and both need to be cut.
On mine it was impossible to use the factory cable clip. I just ignored
I have no suggestion regarding this step, but there's no way anyone
will ever get a torque wrench in there to tighten this nut. A little
more instruction about how to do this would help. Is it okay to take
the throttle to the stop and then torque it, or might that harm something?
Mine is tightened as tight as I could get it by holding the pulley segment
with my free hand. Is that tight enough -- I don't know, actually.
Good. Except perhaps add: be careful not to damage the wires from the
switch as the switch assembly is turned.
This step could be improved.
First, it's almost impossible to twist one's head around to see what
is in figure 16B and even more difficult to remove connectors and add
Figure 16A is a cumbersome picture and tells me nothing
Why refer to 1N when it's not written anywhere in my Scion XA?
Is picture 16C the pin side of the connector or the wire side? -- I
still don't know.
After much cursing, I finally got to the connector that I thought was
the correct one and unplugged it, but there was no green wire. So, I
thought I had the wrong connector. I painfully removed the adjacent
(outboard) and found no green wire there either. After rereading the
instructions, I noticed that an XB has a black & white wire. Since
I had a black & white in the first removed connector and it was
a fairly big wire and it was either in position 6 or 10 depending on
whether figure 16C is pin side or wire side, I assumed the instructions
made a mistake and the black and white was the wire I was looking for.
So I painfully attached my brown wire there -- it didn't work.
My fix was to go to AutoZone and a get an add-a-circuit fuse, which
I put in the unused fuse slot above the 15 amp ACC fuse. The add-a-circuit
fuse is far superior to the procedures in step #8, and in my opinion
should be included in the Scion cruise control kit.
This step isn’t very good either.
Why specify connector numbers when the numbers aren't written anywhere
on my XA?
Figure 20 is too poor to determine which connector is the one needed.
Figure 19 is the pin side of the connector, which is not specified,
and since the installer never sees the pin side, the installer would
assume the picture is of the wire side. This makes for confusion, especially
since the installer doesn't know at the time figure 19 is studied which
connector is the one needed.
This instruction should have just said: VSS is on the second connector
from the right, the rightmost wire in the second row up, which is a
violet & white wire.
Good. Except the instructions should specify if the hole is drilled
in front or in back of the rib on the inside of the column cover. If
I followed the 5/8" instruction, the hole came out on the rib.
I mounted mine to the back of the rib (closer to the steering wheel)
and it seems to me to be the ideal position for the control.
My XA is a manual, so I have no idea if there are any problems finding
the NSS wire.
My cruise control works very fine. I'm happy I bought it. All the parts
(except step 8) fit nicely. The control module location works well.
The throttle actuator fits easily and correctly on the throttle shaft.
The connectors for splicing into the brake switch and the included new
clutch switch are Scion-specific and fit perfectly. The kit is designed
for the Scion, and results in a nice installation."
It took me about 3 hours to install it. If I installed another one,
it would take about one hour assuming I used an add-a-circuit fuse.
I'm a retired computer repairman.
Hope this helps.
Neil Adler's installation remarks:
The mechanical portion of assemble is relatively easy,
the electronic portion is confusing because of the overly hard-to-decipher
diagrams. It took about 4½ hours and works well. Look at these
comments along with Clifford Faith's
comments and the manual.
Step 1 and 2
I agree, do not remove Main Wiring Grommet, simply cut it on engine
side, punch a screwdriver through, then cut in interior and threar Cruise
Cable Assembly follows Vehicles Throttle cable, but cannot easily tie
to it or fit in cable clip. Doesnt seem to matter as long as free and
#1. Hard to see which cable nut is "rear",
but either of the 2 will accept Throttle Lever bracket, and won't matter
as long of length is adjusted to slight slack (0.06 - 0.10) The comments
on the bottom of page 5 in box below #5 say to remove
threaded snap in connector to adjust slack but don't say how. Take a
screwdriver and gently pry out the fitting. Then is is easy to adjust
and readjust until there is slight play. Again not critical I think.
Brake switch is the black connector at the top of brake pedal, not the
white one further up under dash.
This is where the instruction fails. You cannot intepret or find the
so called Black 1N connector or wire 6. Ignore all diagrams. What is
needed is only to get ignition switchable power to the brown wire of
the Harness Assembly. This is easily done by cutting off its connector
and clamping or soldering a 'U' connector on and then placing this on
an unused terminal of the front of the fuse box. You can test or trial
and error for a power slot that is switchable, i.e. has power only when
ignition is on. Since the cruise has 2 fuses of its own I can't see
why you need to use the specific #6 wire as mentioned. Mine is working
perfect. For what it's worth, Fig 16C and Fig 19 do refer to pin side
connectors, thus are mirror images to what you see.
Really easy, as Clifford states, VSSin #17s on second connector from
right, wire is second row up , righmost violet and white wire. By same
method NSS is Third row up, right most Black wire. Snap on connectors
work well and fit under snap on plastic cover.
This was hard until I realized the lower steering cover has 3 screws
and requires rotating the asymetrical steerng wheel to access. When
you measure carefully you will drill precisely at a plastic fin on the
back side, which you must trim or tear off with pliers to get shroud,
lock and jam nuts to fit. The location came out fine, and can be further
adjusted for precise access.
When finally attaching to control switch to module assembly remember
to use the 4 pin adn 2 pin connector housings in the parts, or you may
blow the 4 amp fuse as I did.
The only parts left over were the clutch assembly (mine is automatic)
and the larger M-6 bolt which I am yet to find.
Ethan Upper's installation remarks:
Definitely no need to remove the grommet. Just make the cuts with an
Xacto knife in the place shown, on the inside and outside membrane.
I taped a length of thin wire to a screwdriver and poked it through
the slit in the grommet. Then I wrapped the wire around the cruise harness
and used a 'pull-feed" to get it through. This was the step I was
most nervous about since it involved actually cutting into something,
but it was no big deal. The supplied putty works very well for sealing
the slit around the cruise harness.
No major problems, but the mounting bracket forced me to install the
control module at an angle, with the front canted upward, in order to
accommodate the throttle cable that runs beneath it.
I was not able to run the cruise throttle cable through the throttle
cable clip (unless I wanted to bend it at an awkward angle), nor was
there really a convenient place to use wire ties to secure it. I did
loop one around the cruise throttle cable and engine throttle cable
right next to the throttle cable clip, but I didn't tighten it. I don't
think there will be a problem.
Step 4: This step took some fiddling to figure out and
get right. You will probably want to remove the throttle cable bracket
(Part 2A) from the cable before attaching to the OE throttle cable.
Unclip the plastic 'Threaded Snap-In Adapter" from the cable bracket.
I had already attached everything before I realized that I had about
3 inches of slack in the cruise throttle cable, so I had to remove the
cable bracket, unclip the threaded adapter from the bracket, adjust
the threaded adapter and then reassemble everything. I don't own a torque
wrench, so I just tightened everything as tight as seemed prudent.
Step 5: Where is step 5??? I don't see a step 5! Oh well…Moving
Step 6: Piece of cake.
Step 7: (My xB is an automatic transmission so I skipped
Step 8: This was a VERY frustrating step. But I don't
think it has to be, and I figured it out without changing anything or
buying any other parts. I read the other installation notes and decided
I wanted to do it the way the manual said. I tried unsuccessfully for
about 30 minutes to disconnect the connector and then left it and moved
on. After I finished with everything else, I went up and got a flashlight
and borrowed a small handheld mirror from my wife. Using those I was
able to identify the wire running to pin #6 and fish it out enough to
get the T-tap connector on it. In the xB at least, it is indeed a black/white
wire. The diagram shows you the pins with connector facing you, as if
you were going to plug it into your face. (Hee hee) So the wire you're
looking for is on the bottom row, the second wire in. (Starting from
the outboard side of the car.) I got the right wire, as my cruise control
works perfectly and only switches on with the ignition.
Step 9: No problems. Just had to take it slow and make
sure I had the proper connector for my vehicle and matched up the wires
properly. Keep in mind that the diagrams show the pins with the the
plug's 'business end" facing toward you.
Step 10: No problems at all. Good instructions. Had to
clean up the hole with the Xacto knife and remove a little bit of the
inside reinforcing rib.
In conclusion: I had intended on getting a professional
installer to take care of this for me, but now I'm glad I just did it
myself. When I first read the instructions and looked at the tangled
wiring harness I was pretty apprehensive. I don't generally work on
cars, but I am trained as an electronic technician and I guess some
of the basic skills came in handy. The other installation notes on this
site were VERY helpful. I read through the whole manual about three
times first, which I would recommend.
This will sure make my upcoming 3500 mile road trip a