Cruise Control not working KV6

StewartIngram · 15th September 2019, 17:37

The cruise control on my petrol KV6 appears to have failed. Though I am an infrequent user, I do remember using it; I only bought the car last November.
Symptons are:
1 - main switch operated, green light comes on. (I'm assuming switch and fuse are ok).
2 - steering wheel switch (SET) operated - dashboard icon comes on, but speed (say 50mph) is NOT maintained. (I'm assuming switch works as icon now lit).
3 - as 2, but switch used for (+) mode, no increase in speed. (Same assumption as 2).
4 - leaving SET selected, with icon lit, but using accelerator to drive; if brake pedal is now used, icon goes off. (thus I am assuming brake pedal switch is ok). Note - I have added an led repeater for the brake lights, I can confirm brake lights and icon go off together.
5 - Vacuum pipe to throttle body; I have checked for cracks and disconnection, but NFF, though I have yet to go under car to check vacuum pump closely.

Any suggestions?

Stewart

Ched · 15th September 2019, 21:52

I had the same, turned out the pump didn't work, replaced and all was well.

SD1too · 16th September 2019, 07:02

Quote:

Originally Posted by StewartIngram

I have added an led repeater for the brake lights ...

Stewart; have you tried temporarily disconnecting your modification to see if it makes any difference?

Simon

kaiser · 16th September 2019, 07:12

It could be as simple as the vacuum pipe off the diaphragm housing (activating the throttle) having come off, or the adjusting rod having lost "grip". Both are simple fixes.

StewartIngram · 16th September 2019, 07:26

Quote:

Originally Posted by SD1too

Stewart; have you tried temporarily disconnecting your modification to see if it makes any difference?

Simon

Actually no, but the modification is a simple led in parallel with the rear bulbs, would have no effect on the circuitry at all. I put that on (transferred from the previous car) as soon as I got the car, have used it for a number of years.

Stewart

StewartIngram · 16th September 2019, 07:28

Quote:

Originally Posted by kaiser

It could be as simple as the vacuum pipe off the diaphragm housing (activating the throttle) having come off, or the adjusting rod having lost "grip". Both are simple fixes.

As stated in (5) above, I have checked the vacuum pipe. Couldn't see anything amiss with the linkage either.

Stewart

buchanan · 16th September 2019, 18:13

Have you pressed the reset, my light come on the switch but the icon not showing on the screen, I operated the reset and icon appeared and cruised control worked,

StewartIngram · 16th September 2019, 19:36

As in (2) above, icon does come on. I have also tried the reset switch on the wheel.

Stewart

COLVERT · 16th September 2019, 19:49

Quote:

Originally Posted by Ched

I had the same, turned out the pump didn't work, replaced and all was well.

I have a diesel so it has to have a vacuum pump.

Does the V6 petrol have a vacuum pump ??

I thought the vacuum was taken off the inlet manifold.--

Ched · 16th September 2019, 20:53

Yes the v6 has a pump, its located in the engine bay side of the o/s wheel arch.
The vacuum pipe goes from the pump to the bellows unit mounted on the side of the throttle body.
Landrovers also use the same pump so not too hard to find a replacement.

15th September 2019, 17:37	#1
StewartIngram Gets stuck in Rover 75 Connoisseur 2.5 V6 auto Join Date: Jan 2008 Location: Chatteris, Cambridgeshire Posts: 902 Thanks: 320 Thanked 159 Times in 127 Posts	Cruise Control not working KV6 The cruise control on my petrol KV6 appears to have failed. Though I am an infrequent user, I do remember using it; I only bought the car last November. Symptons are: 1 - main switch operated, green light comes on. (I'm assuming switch and fuse are ok). 2 - steering wheel switch (SET) operated - dashboard icon comes on, but speed (say 50mph) is NOT maintained. (I'm assuming switch works as icon now lit). 3 - as 2, but switch used for (+) mode, no increase in speed. (Same assumption as 2). 4 - leaving SET selected, with icon lit, but using accelerator to drive; if brake pedal is now used, icon goes off. (thus I am assuming brake pedal switch is ok). Note - I have added an led repeater for the brake lights, I can confirm brake lights and icon go off together. 5 - Vacuum pipe to throttle body; I have checked for cracks and disconnection, but NFF, though I have yet to go under car to check vacuum pump closely. Any suggestions? Stewart

16th September 2019, 07:12	#4
kaiser This is my second home 75 Tourer 2.5 Auto, 1.8T, 75V8ZT Join Date: Jun 2007 Location: Johannesburg ZA Posts: 6,200 Thanks: 1 Thanked 859 Times in 613 Posts	It could be as simple as the vacuum pipe off the diaphragm housing (activating the throttle) having come off, or the adjusting rod having lost "grip". Both are simple fixes. __________________ Worth his V8 in gold

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15th September 2019, 21:52	#2
Ched I really should get out more....... MG ZT V8, MGZT 135 derv ,MG TF 135 Join Date: Dec 2011 Location: Romsey Posts: 2,293 Thanks: 553 Thanked 573 Times in 385 Posts	I had the same, turned out the pump didn't work, replaced and all was well.

16th September 2019, 18:13	#7
buchanan Buchanan Rover 75 connoisseur se ctdi Auto Join Date: Feb 2010 Location: Belfast Posts: 332 Thanks: 3 Thanked 30 Times in 18 Posts	Have you pressed the reset, my light come on the switch but the icon not showing on the screen, I operated the reset and icon appeared and cruised control worked,

16th September 2019, 19:36	#8
StewartIngram Gets stuck in Rover 75 Connoisseur 2.5 V6 auto Join Date: Jan 2008 Location: Chatteris, Cambridgeshire Posts: 902 Thanks: 320 Thanked 159 Times in 127 Posts	As in (2) above, icon does come on. I have also tried the reset switch on the wheel. Stewart

16th September 2019, 20:53	#10
Ched I really should get out more....... MG ZT V8, MGZT 135 derv ,MG TF 135 Join Date: Dec 2011 Location: Romsey Posts: 2,293 Thanks: 553 Thanked 573 Times in 385 Posts	Yes the v6 has a pump, its located in the engine bay side of the o/s wheel arch. The vacuum pipe goes from the pump to the bellows unit mounted on the side of the throttle body. Landrovers also use the same pump so not too hard to find a replacement.