speed signal.

[ajmackie]

Hi

I have an audi a4 1999. i am retrofitting cruise control using an aftermarket kit (not oem audi) and i need to give it a speed input. Does anyone know what signal the auto volume system on the conert radio receives. is it encoded or is it a simple pulse?

does the speedo signal receive a pulse for every revolution of the driveshaft?

jst wondering as it comes with a magnetic sensor which attaches to the drive shaft, but if i can use one of these signals then it would save a bit of time and hassle!

Thanks a lot /ubbthreads/images/graemlins/beerchug.gif

 

[dunk]

if you use the gala signal from the back of the radio, you get 8 pulses per wheel revolution (newer gala models) or 45 pulses for older cars using the ABS signal

your should be using the gala - its a simple pulse

 

[ajmackie]

darn! i just need 1 pulse per wheel revolution!
if i had bought the more expensive kit it would have "learned", but this one will think it's going 8 times as fast when i press resume. i think! or will that still work??? hmmmmmm!

it might work depending on whether it is programmed to recognised 20 pulses per second as say 70mph or whether it counts how many pulses it gets when travelling at 70mph.

Will have to just wait and see methinks! Do you know what signal the speedo receives, or for that matter the revs as it can work off both.

Thanks for your help

 

[audi5e]

I would imagine that it would work from the pulse readout. Only problem might come if the unit restricts top speed. I know a lot of modern cruise control units have set 180km/h as the highest usable cruise speed. If you are getting 8 pulses instead of 1 then your unit would quickly get to its limit.

 

[ajmackie]

Does anyone know which wire it is on the back of the headunit?

Might try it and then if it doesn't work i'll use the magnetic speed sensor. I can adjust the sensitivity of the unit so that i won't count every pulse.

 

[audi5e]

Worth a try. Not sure about the wire from the headunit though.

 

[ajmackie]

no probs!!! wire up the vacuum and no vacuum!! going to go to a garage to ask which hose it is! There are rigid plastic hoses on the brake vacuum, must probably be that one as I took a soft rubber hose from after the carburettor!

trial and error!!

 

[ajmackie]

sorry i didn't mean carburettor. i meant the throttle!
i'm going to go to a garage and ask which hose it is and where the non return valve is!

 

[audi5e]

probably wisest. at the least they ought to know which pipes not to touch...

 

[ajmackie]

yep got the working!! wahoo! just need to find the speed signal now!!!

 

[RichA3Turbo]

[ QUOTE ]
ajmackie said:
yep got the working!! wahoo! just need to find the speed signal now!!!

[/ QUOTE ]

Are we talking mph speed or rpm speed?

Rich

 

[ajmackie]

either. pref mph, but can work off either!

it is all tested and working bar the speed input

 

[dunk]

GA is the gala signal - does your car have a wire going to this connector from the car loom? if so, then gala is connected properly.

 

[ajmackie]

yeah it does and it is blue/white. it must not be compatible with the cruise control speed input. will have to use the magnetic sensor on the drive shaft methinks!

Would the gala signal be exactly the same signal as the speedo receives?

 

[ajmackie]

I've had a look with the multimeter at the magnetic proximity sensor. i was checking continuity and with the magnet there, there is none. i checked votage and it is generating an ac voltage of about 20mv with each pass.

Is there any speed related signal on the car which I could use to replicate this, ie the speedo signal to the speedo clusters? Is this the same signal that gala uses?

Any help really appreciated as otherwise I'm going to have to get my car on ramps and fit the sensor that comes with it!

 

[ajmackie]

Wahoo!!!!!!!!! Just spent an afternoon under my car and i've got the cruise control working now after fitting the supplied sensor!!!! Wahoooooo!!

 

[imported_Yaseen]

/ubbthreads/images/graemlins/dancing.gif

congratulations man! You put a lot of effort into that, glad its all sorted /ubbthreads/images/graemlins/dancing.gif

 

[ajmackie]

i know!!! a lot!! i could do it so easily now it's done!
Was annoying as I didn't have all the right tools so took a while to work around or go and get them!!
Just been 50 miles on the motorway and it is so so so much easier to drive with cruise control! lurving it!!!

 

[audi5e]

well done mack!

 

[ajmackie]

Cheers, thanks for your help!