Cruise control stopped working

[dmz]

Morning All,

 

Hope this is the right place for this, I've had a quick scan over and haven't found something exactly like this so here goes...

 

In a nutshell, the factory fitted cruise control on my fabia has stopped without warning, came as a bit of a surprise on the way up the M6 after getting comfy for a long trip.

 

I've got access to vagcom/vcds and have had a quick look and not really knowing what the results should be on a working model, this is what I've found:

 

BP Up - CC Switch on

----------------------

Brake Pedal

F/F47/F36

1/0  /0

 

Cruise System 1.0

 

BP Up - CC Switch off

----------------------

Brake Pedal

F/F47/F36

1/0  /0

 

Cruise System 0.0

 

BP Pressed - CC Switch on

----------------------

Brake Pedal

F/F47/F36

1/1  /1

 

Cruise System 17.0

 

BP Pressed - CC Switch off

----------------------

Brake Pedal

F/F47/F36

1/1  /1

 

Cruise System 0.0

 

Pressing the clutch doesn't seem to change any values.

 

Figured if it was something simple I'd dig out a manual and try to fix it myself, I've heard that the switches in the pedals sometimes go, but I'd rather not go blindly replacing parts without knowing at least the basics.

 

I'm open to any ideas, gotta learn this stuff at some point 

 

Thanks

 

dmz

 

[dmz]

Bit more investigation yielded that it's looking like the clutch switch that's gone.

VCDS measuring blocks group 6 didn't yield the normal bin dump in field 3 (was a %age instead)

Looking thru the blocks, and a bit of label file tinkering, block 22 yielded the right array of switch settings to see what switch was dodgy.

On the assumption that the active bit didn't change on pressing the pedal, but shorting the 2 pins yielded a change, it's a fair guess.

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[fabiamk2SE]

Good of you to keep the thread updated.

Id like to help, but iv no idea what most those codes mean haha.

Out of interest, what year is the car mate?

[bluecar1]

yep, either brake or clutch switch would have been my guess

 

surprised you don't have issues starting it if the clutch switch playing up? as if like my fabia you have to push the clutch down to start it

 

curiosity can you start it without pushing the clutch down? i.e. the switch has failed so the ECU thinks the clutch is down all the time?

[fabiamk2SE]

That must depend on engine?

I can start mine without pressing the clutch. I do press it on start up though, cos i think its good practice. Take a little stress off the starter motor n all that

[bluecar1]

mine displays "CLUTCH" on the display (not got maxidot) and starter will not turn until the clutch is depressed

[fabiamk2SE]

What year n engine is it?

I cant see on my phone aha.

[jonro2009]

My 13plate Monte starts without pressing the clutch.

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[dmz]

It's an 08 reg 1.9 BSW, so no maxidot.

Interestingly no fault codes..

I've had the switch in bits and there is a little bit of copper strip that's snapped off what closes the circuit.

Going to local dealers tomorrow to see if they got a spare, car starts fine without it, since from looks of it it was reading clutch as permanently disengaged/down.

Afaik, since it's not an auto it has no other effect other than to disengsge CC. (if that's wrong let me know, it's just a calculated guess).

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[Tech1e]

The engine ECU uses the clutch signal for altering fueling and timing when changing gear and or stopped/stopping.

[dmz]

That explains why is been a bit twitchy as of late

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[dmz]

Right, final update then

Just fitted new clutch switch, like a muppet didn't take the lower dash off, so was playing contortionist... Came out easy enough but getting new one back in was fun.

New revision switch looks a lot more substantial which is good.

All checks out OK on vcds, cruise control back working again, and there is no longer the stutter as I lift off the throttle. Job done!

Thanks for those who commented, the input is appreciated

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Edited 27 May, 2014 by dmz

[fabiamk2SE]

Glad you've sorted it .

[jonro2009]

Enjoyed reading this thread, means nothing to me as I don't have VCDS or CC but it was interesting and kept well up to date

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[freelanderman]

Shows just how useful vcds is.