DIY Cruise Control on 07-08 Yaris (step by step)

[CTScott]

Originally Posted by goat1of2

And yet *another* new Yaris owner gives this a try......

It seems that y'all are saying that we should disconnect the battery before pulling off ECM connector A21. Yet, won't I need the battery connected to check if 12V is present at pin 40? That's right, I've never messed with the electronics in a car before.

Also, I'm looking at the document so kindly provided by Vince87 and I cannot for the life of me find Connector D3 either. I have a very late model 2008 and wanted to make sure that the wires I need aren't already in the cabin. There's a whole passel of connectors under that dash, most of which I cannot see because of all the plastic covers. Do I need to remove some of them?

Check out this link for a comprehensive list of links related to installing cruise control:

http://www.yarisworld.com/forums/sho...ght=cruise+faq

This picture from my 09+ DIY shows D3 (the leftmost connector with the brown, blue and black wires):



You need to remove the lower steering column cover to gain access to it.

As far as disconnecting the battery goes, you should do so while doing the wiring to the ECM. Checking for 12V on pin 40 is really only necessary if you have issues with it not working, and in that case, you'd measure the voltage at that pin via the wire that you connected to it.

[goat1of2]

Originally Posted by CTScott

You need to remove the lower steering column cover to gain access to it.

As far as disconnecting the battery goes, you should do so while doing the wiring to the ECM. Checking for 12V on pin 40 is really only necessary if you have issues with it not working, and in that case, you'd measure the voltage at that pin via the wire that you connected to it.

Thank you sir. I found my Connector D3 and confirmed that I will need to run a wire from the ECM. Now to order the parts....

Perhaps the language in the pdf should be amended to read: "...connector D3 on the left side of the steering column (under the plastic housing)". I was taking "under the dash" to mean well, under the dash!

In case anyone finds it useful, the build date for my Yaris was May 2008; apparently they were not yet incorporating any features from the 2009 cruise control setup yet!

[lily]

I need some help from this install.

Got an '07 Yaris HB, base model, auto.

I did the 2 button setep from CTScott's PDF write-up.

I cannot get the 'cruise' to work after this mod.

What I did was soldered two resistors in series: a 270 and 380 for a 650 resistor. Then soldered the series as shown on the PDF for the 2 button setup.

I ran a wire to the PIN 40 on the ECU and grounded the other wire, but still nothing.

My questions are:

How far does the wire going into the ECU have to "stick" out to touch inside the ECU?........I have maybe 2 or 3 wires that stuck out from the harness, is that enough "contact" to make this work?

I grounded the other wire by just screwing/sandwiching into a grounded source on the driver's kick panel, <<< is this "good grounding"???

Is soldering a good idea to connect the series? <<< I soldered because the pins behind on the push buttons I got from Radio Shack were too small to work on.

I hope I am clear about my questions. It has been raining here so I would like some help soon so I could use this feature on my upcoming road-trip.

Thank you for your time.

[CTScott]

Originally Posted by lily

I need some help from this install.

Got an '07 Yaris HB, base model, auto.

I did the 2 button setep from CTScott's PDF write-up.

I cannot get the 'cruise' to work after this mod.

What I did was soldered two resistors in series: a 270 and 380 for a 650 resistor. Then soldered the series as shown on the PDF for the 2 button setup.

I ran a wire to the PIN 40 on the ECU and grounded the other wire, but still nothing.

My questions are:

How far does the wire going into the ECU have to "stick" out to touch inside the ECU?........I have maybe 2 or 3 wires that stuck out from the harness, is that enough "contact" to make this work?

I grounded the other wire by just screwing/sandwiching into a grounded source on the driver's kick panel, <<< is this "good grounding"???

Is soldering a good idea to connect the series? <<< I soldered because the pins behind on the push buttons I got from Radio Shack were too small to work on.

I hope I am clear about my questions. It has been raining here so I would like some help soon so I could use this feature on my upcoming road-trip.

Thank you for your time.

You really need to have good connection to the ECM pin and realllllly want it to still be waterproof, so using one of the correct pins for the connector is a good idea.

Soldering the resistors is definitely the way to go. In the example pictures of the two switch methods I just put them together to show the layout, but didn't solder the examples.

[lily]

how would the connection pin to the ECM look like?

i may have some extra pins left from the tacoma.

[CTScott]

Originally Posted by lily

how would the connection pin to the ECM look like?

i may have some extra pins left from the tacoma.

ECM Pin.jpg

[lily]

well, i re-wired new push buttons and added a new single 620 resistor to the 2-button setup but still no avail.

i'm thinking that the connection to PIN 40 is not so good.

how did you all establish "connection" to this PIN 40?

did you just simply push a strand of wire through the harness or actually got one of those little pins? (i just pushed a wire through the harness because i cannot figure out how to completly disassemble it).

can the head piece of harness be taken apart further? <<< i have take it off the ECU/ECM and the taken the little rubber plug off but cannot figure out if the head piece of the harness can be taken apart further.

Thank you.

[goat1of2]

Originally Posted by CTScott

Soldering the resistors is definitely the way to go. In the example pictures of the two switch methods I just put them together to show the layout, but didn't solder the examples.

Ah ha! I was wondering about that. This is like when we women give recipes by just mentioning a few ingredients...there are a whole LOT of steps which are simply assumed. As more inexperienced people like myself attempt this mod, you'll be getting all kinds of seemingly "dumb" questions. Like this one:

I've got some AWG 20 wire, but it is single-strand copper instead of the multi-strand silver-looking stuff I see all you guys used. Will this work? Can I solder it? Will it corrode if mixed with whatever other metals are involved?

See what I mean?

[Project status: resistors and switches on order from Digikey, proper ECM connector on order from Toyota]