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

[CTScott]

Originally Posted by weaver615

Ok Guys I tried this MOD today and it doesn't work. I used 2 NO Switches and 1 680ohm 1/2 5% cfr resistor, grounded to chasis at the drivers side door and hot to PIN 40 of the ECM. Jumpered the Clutch switch and took it for a test drive. NADA.
I'm wondering if the resistor may be the problem or if the problem could be that I used 20 Gauge solid and not stranded wire, (shouldn't make a difference I wouldn't think), to build the circuit and run the hot and ground. every thing checked and doubled checked, any Ideas? BTW, I am using the 2 switch method not the 4.

How did you make the connection to pin 40?

Solid vs stranded shouldn't make a difference, but with the 680 ohm resistor being near the top end of the range (567-693 ohms), if your 5% tolerance is off in the + direction, then you may be out of range for the set function. +5% on 680 puts you up to 714 ohms.

[weaver615]

I made the connection direct to PIN 40 on the ECM. Ran positive wire thru firewall to the ECM pushed out the rubber block and fed the wire down til it came out the other side and trimmed it as close to the connector as possible. Put the wire shield back on and re-connected the ECM....Should I try using 2 - 330ohm resistors they are a quarter watt but the wattage shouldn't make that much of a difference I don't think should it?

[CTScott]

Originally Posted by weaver615

I made the connection direct to PIN 40 on the ECM. Ran positive wire thru firewall to the ECM pushed out the rubber block and fed the wire down til it came out the other side and trimmed it as close to the connector as possible. Put the wire shield back on and re-connected the ECM....Should I try using 2 - 330ohm resistors they are a quarter watt but the wattage shouldn't make that much of a difference I don't think should it?

Since you are using a wire, rather than the connector pin, make sure that the connection is good. You can measure the voltage at the other end of that wire and with the ignition on it should be 12V.

For the resistor(s), 1/4 watt is fine (even 1/8 watt would be fine, as the current draw is negligible).

[weaver615]

Whatt would you suggest? Leave the wires as they are and cut at the switches and rebuild the circuit then splice back into the wires already ran, I would rebuild it using a radioshack 560 ohm 1/2W 5% Carbon Film Resistor. Or, should I just tear everything out and start fresh, new circuit, new wires, etc. Thanks for the help I really appreciate it. I want Cruise soo bad!!!! lol

[weaver615]

Would it be safe to leave the clutch jumpered until I can buy the acutal switch from the dealer? I know I would have to be careful NOT to push the clutch down until after I disengaged the cruise.

[CTScott]

Originally Posted by weaver615

Whatt would you suggest? Leave the wires as they are and cut at the switches and rebuild the circuit then splice back into the wires already ran, I would rebuild it using a radioshack 560 ohm 1/2W 5% Carbon Film Resistor. Or, should I just tear everything out and start fresh, new circuit, new wires, etc. Thanks for the help I really appreciate it. I want Cruise soo bad!!!! lol

You could rebuild it and splice it back in.

[CTScott]

Originally Posted by weaver615

Would it be safe to leave the clutch jumpered until I can buy the acutal switch from the dealer? I know I would have to be careful NOT to push the clutch down until after I disengaged the cruise.

It is, as long as you do remember.

[CTScott]

Originally Posted by weaver615

ok Scott I'm gonna try to rebuild the circuit and splice it back in. The 560 ohm 1/2w resistor with 5% CFR would be ok right? It would put me at 588 ohms almost at the middle of the scale but better than 714 ohms. Another thing I just noticed is the switches I bought Radioshack catalog #: 275-644 don't say whether they are NO or NC, Would these switches Radioshack catalog #: 275-1566, be better? I know they have to be NO switches, just wondering if that could be the problem I got NC instead of NO switches.

A 560 is probably too low. The 5% can go either way, so if you use a resistor close to either end, you really should check it with an ohm meter to verify what the actual value is. Being within the range is critical. If you are out of band, the ECM will not recognize the function.

The 275-644 switches are N.O., so they are fine.

[weaver615]

ok I checked my NEW switch and have 12 volts at the circuit end of the run wires with the ignition in the "on" position, so I have a connection to the ECM. Still nada. I'm stumped.

I'm thinking I should use 2- 330 ohm resistors, that would put with in the band +/- 5%.

[CTScott]

Did you check the actual resistance of your resistor?

[weaver615]

Scott, just replaced risistors with 2 330 ohm resistors, still nada, resistance at 630 well with in the band...I am perplexed....now what?

[CTScott]

Originally Posted by weaver615

Scott, just replaced risistors with 2 330 ohm resistors, still nada, resistance at 630 well with in the band...I am perplexed....now what?

Take pictures of everything - Switch wiring, clutch switch bypass wiring, ECM connection point.

[weaver615]

ok here are pics of my DIY cruise control on a 2007 Yaris 5 speed Manual transmission.

PIC 1: switch with circuit Used 680 ohm resistor. Splice in place after redoing circuit. Red wire to PIN 40 on ECM Black wire to ground at drivers side door.

PIC 2: ECM with Red wire at PIN 40.

PIC 3: Clutch jumpered at fuse box done using nickhjort's method.

PROBLEM: Cruise doesn't work. ON/OFF swtich doesn't seem to get power. SET doesn't engage.

HYPOTHESIS: Either bad switches (second set), or ECM doesn't support Cruise Control.

Where do I go from here?

[CTScott]

On the ECM you have the correct position.

The clutch switch bypass is in the correct position.

The switches look fine. In the pic the top one is on/off and the bottom one is set.

With the ignition on, if you measure from the red to the black wire on the top switch, what do you see for voltage?

[weaver615]

Voltage with ignition in on position Almost 13 volts (analog meter here). With Ignition off 0 (zero) volts.

[CTScott]

And, if you press the top switch it goes to 0 volts?

[weaver615]

Yupper goes to Zero Volts. BTW< the resistor I used is the 680 Ohm resistor from radioshack that you get in the $12.99 package of resistors.

[CTScott]

OK. How about the clutch switch bypass - Do you have definite contact between the connector pins and your jumper? With the ignition on, both the blue and white wire terminals should measure 12 V.