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

[yongtaufoo]

Hi guys,

Im trying to install cruise controls for my Yaris (Automatic Transmission) and would like to get some advice from the experts here before proceeding with my DIY:

My ECM A21-40 has a 12V with ignition on. So now all i need to do is to connect the cruise control stalk CCS pin to A21-40 and ECC pin to ground correct?

Do i need to do any other modifications for cruise control to work?

Thanks!!

[CTScott]

Originally Posted by yongtaufoo

Hi guys,

Im trying to install cruise controls for my Yaris (Automatic Transmission) and would like to get some advice from the experts here before proceeding with my DIY:

My ECM A21-40 has a 12V with ignition on. So now all i need to do is to connect the cruise control stalk CCS pin to A21-40 and ECC pin to ground correct?

Do i need to do any other modifications for cruise control to work?

Thanks!!

That's it for an Auto.

[yongtaufoo]

Originally Posted by CTScott

That's it for an Auto.

Hi Scotts,

Thank you so much for your reply.

But im puzzle about another thing. If referring to the cruise control switch schematic, turning cruise control ON-OFF will short ECM Pin40 12V to ground. Will I then damage my ECM by doing this since it is outputing a 12V? And ECM Pin40 is an input or output port?

Thanks!

[yarstar]

One more CC done! Thanks to CTScott and all who contributed. A suggestion if you have the TB upgrade: you will need to disconnect the battery while doing this DIY so the ECM resets. Only disconnecting the one plug causes the initial ocillation to return. For some reason it won't learn until you completely reset the ECM.

I want to pass on a couple of 680 ohm resistors that I was given to anyone who needs them. You only need one to do the 2-button setup. PM me with an address and I'll mail one to you.

Thanks again CTScott. This was the only thing my car was missing.

[weaver615]

Originally Posted by yarstar

I want to pass on a couple of 680 ohm resistors that I was given to anyone who needs them. You only need one to do the 2-button setup. PM me with an address and I'll mail one to you.

I too have a few of the 680 ohm resistors that I can donate to someone looking to do the 2 button setup. I also have some 120 ohms too if someone wants to do the 3 button setup like I did. PM me your address and I can send them out to you.

[CTScott]

Originally Posted by yongtaufoo

Hi Scotts,

Thank you so much for your reply.

But im puzzle about another thing. If referring to the cruise control switch schematic, turning cruise control ON-OFF will short ECM Pin40 12V to ground. Will I then damage my ECM by doing this since it is outputing a 12V? And ECM Pin40 is an input or output port?

Thanks!

Pin 40 is an analog to digital port on the ECM. The 12 volts is a reference voltage and the ADC has about 2k ohms of internal resistance, so shorting that pin to ground just brings the ADC to the bottom of it's 0-12 volt input range.