Crazy cruise control problem

[Jon1796]

If you’re sure it’s 200-50 lower then it’s not same box.


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[KitS]

Hmmmmm, the plot thickens.

[Steel]

Just been having a play with my Bosch ESI software and there are various configuration settings to enable and disable cruise control and ESP and to configure for different transmissions, but I can't see how any of that would have been changed given the fact that they only changed the casing. I know you can also program for different tyre sizes which could account for the speed differential, but why would any of that have changed either?

[Jon1796]

Just been having a play with my Bosch ESI software and there are various configuration settings to enable and disable cruise control and ESP and to configure for different transmissions, but I can't see how any of that would have been changed given the fact that they only changed the casing. I know you can also program for different tyre sizes which could account for the speed differential, but why would any of that have changed either?

They haven’t changed any of your settings they’ve changed your box as you said earlier your now rev 200-50 lower in every gear probably the 2.2 ratio. So you can ether take it back and explain to them what’s wrong or try and and reconfigure cim to 2.2 to see if that gets cc working.


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[KitS]

I've tried explaining the problem to them, but I get the '...nuffin to do wiv us guv, we just fixed the box....' response.

They can't see there's any connection between my lack of cruise control and replacing the gearbox casing. And of course it's just a co-incidence that the CC stopped working on 4 of the six gears at the same time as they repaired it.

Yeah, right.............

[Dog_Book]

What on earth has the gearbox got to do with the cruise control then since it works at different revs and speeds?

[Jon1796]

What on earth has the gearbox got to do with the cruise control then since it works at different revs and speeds?

quite a lot, do forty mph N put on cc no go. Now forty mph in ‘A’ gear cc will work, with no other sensors on lever or in box it’s the only way it can figure out your in a gear.
So a preset engine with gearbox ratio will let it determine rev+speed=gear if as he says 200-250 lower then he’s outside parameters until he’s in 3rd and 4 with a small amount off error for tyre size and wear.


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[Dog_Book]

quite a lot, do forty mph N put on cc no go. Now forty mph in ‘A’ gear cc will work, with no other sensors on lever or in box it’s the only way it can figure out your in a gear.
So a preset engine with gearbox ratio will let it determine rev+speed=gear if as he says 200-250 lower then he’s outside parameters until he’s in 3rd and 4 with a small amount off error for tyre size and wear.


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So how does the ECU know what gear its in as apart from the reverse switch Ive not seen any gear sensors on the F40 boxes?

[Jon1796]

Speed and revs, 30 mph at say 2000 rpm would put you in gear ‘B’, 70 mph at 2000 rpm would put you in gear ‘F’, every gear has a rpm and speed which is unique, you can’t do 130 mph in first, you can’t do (well you can)10 mph in sixth


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[Jon1796]

So how does the ECU know what gear its in as apart from the reverse switch Ive not seen any gear sensors on the F40 boxes?

Is your doda manual, does it tell you to change up to gear ‘X’, no sensor on lever or box for gear.


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