2007 FG cruise control project.

[pugslyyy]

I've decided to get serious about doing a better cruise control for my FG. The reality is that there are often significant highway miles between where I am and where I want to be, and this will make them easier.

I want something that will maintain RPMs, not speed. Since I have a manual transmission I'll only be using it once I'm at-speed, not from a stop.

I'm figuring out fitment. The signals that I am looking at are -

1. B34 Accelerator Position Sensor 1
2. B46 Accelerator Position Sensor 2
3. A20 Accelerator Switch
4. B51 Clutch Switch
5. Stop Lamp Switch
6. A25 Tachometer

The outputs I will be manipulating are
1. Accelerator Position Sensor 1
2. Accelerator Position Sensor 2
3. Accelerator Switch

Except for the brake light switch I can pick up all the signals at the ECU instead of having to go to the individual sensors.

 

[yabanja]

You have my attention!!:luxhello:

 

[pugslyyy]

The actual throttle control is pretty darn simple - made a little more complex by the redundancy built in to the accelerator position sensor, which means that two signals need to track pretty much the same to avoid a fault.

What takes time is identifying all the signals you want to pay attention to that should cut the cruise out (like when you tap the brakes, push in the clutch, etc).

 

[boostin]

Oh boy this is my dream to add cruise to my 06. I can help any way I can

 

[pugslyyy]

Here's what I have so far, mainly just collecting data right now.

I've pulled the connectors off of the ECU, taken them apart, and labeled the wires shown. One sign that I'm on the right track is that the one I thought was the VSS already had a splice in it for the nav system.

https://drive.google.com/file/d/0B-qpL8lXUBMLSERONjhhNXF3MG8/view?usp=sharing

(the images are too small to read, you need to get the pdf from google drive)

 

[boostin]

So What are you using for the actual cruise control system?

 

[SkiFreak]

Have you identified an aftermarket cruise control stalk for the steering column or will you simply use a button panel on the dash?

I have often thought of doing something like this myself, but sadly my electronics skills are nothing short of pathetic, which has been my main reason for not perusing a project like yours.

 

[pugslyyy]

So What are you using for the actual cruise control system?

Right now I'm just trying to understand the signals from the vehicle. I may adapt a cheap system or roll my own with an arduino. You can buy systems from Australia, but they are quite pricey.

 

[SkiFreak]

You can buy systems from Australia, but they are quite pricey.

That is true, but on the plus side for you guys on the other side of the planet, you get a 30% discount, as the value of our dollar is in the toilet at the moment.

 

[pugslyyy]

Have you identified an aftermarket cruise control stalk for the steering column or will you simply use a button panel on the dash?

I have often thought of doing something like this myself, but sadly my electronics skills are nothing short of pathetic, which has been my main reason for not perusing a project like yours.

I'm just going to use buttons on the dash, or possibly a Rostra Switch like this http://www.amazon.com/Rostra-Wireless-Cruise-Control-250-1483/dp/B008BHGN82

 

[dtruzinski]

subscribed! Was just commenting to my wife that we needed a cruise control.

 

[pugslyyy]

That is true, but on the plus side for you guys on the other side of the planet, you get a 30% discount, as the value of our dollar is in the toilet at the moment.

If I were a businessman at heart I would just buy it... but I'm an engineer, so if it is electrical and costs more than say $200 I think "I could make that myself" - even though it may take hundreds of hours of my time.

 

[gait]

keep up the good work,

I find this sort of project totally frustrating as (as identified) all the info is inside the ECU and all that's required is that little bit of logic that says control engine rpm by simulating accelerator input rather than respond to accelerator input. Instead of writing it into the ECU, or communicating sensibly with the ECU, we end up having to cobble it onto the outside.

Do you have thoughts on how to fudge the accelerator position yet?

Just a thought. It occurs to me that on my 2005 FG there's a switch/knob to right (right hand drive) of steering column. Pull it out and rotate it operates as a hand throttle. I believe it connects to ECU with two wires. It may be that those two wires could be coerced for cruise control use. I don't know if there is sufficient range to fully simulate the accelerator pedal as the knob seems mainly intended for quick engine warm up in cold weather.

 

[pugslyyy]

The hand throttle could be used, but I'm going to set mine up in a more conventional cruise configuration (and I also find the hand throttle useful as is).

I worked on the PCB layout for the cruise control module today, here's the current look.





The three relays are the fail safe - I have to intercept and modify three signals (accelerator signal 1, accelerator signal 2, accelerator switch) which is only possible when the relays are actuated.

 

[SkiFreak]

Have you considered using SSRs?