I have been looking on the internet for technical information relating to fault finding the Volvo S60 Cruise Control system. I have a 2001 T5 with a problem cruise control. It will no longer stay switched on via the steering wheel on/off button. It's a strange fault because sometimes it will allow me to switch it on immediately after the engine has been started but within a few seconds it goes off again and will not switch back on. This tells me the electrical system basically works, but something is inhibiting it for whatever reason.
Could it be a dodgy sensor somewhere or a bad vacuum line? I would appreciate any help anybody can give me on this as even the owners guide does not mention fuses, relays etc for the cruise control.[:@]

Most of the time when it happens it is the brake pedal position sensor loctaed in the brake booster under the hood.

I would have thought the brake pedal position sensor may cause a problem when cruise control is on and the speed is set. The problem I have is the light will not stay on the dashboard and sometimes only operates when the car is first started. If you are still advising the brake position sensor is the main suspect could you please let me know exactly where to find it?
Thanks

That might still be it.
Have you had the car checked for codes in the cruise control module and the engine module?

Not yet, I have it booked in for a check over on 9th June.

let me know how you make out.

Thanks for all your help. I have had it looked at now by Volvo and it has turned out to be the Clutch Master Cylinder leaking fluid onto the Clutch Sensors below. This had the effect of not providing clutch lever positional info to the control unit.
It's a strange one because I also noticed there was no 'damping' on acceleration and deceleration as I was now used to with this model Volvo. This meant there was a lot of jerking when the accelerator was depressed and released and I was starting to think something mechanical was wearing out. Once these units were replaced both problems went away.
The cost was £331.53 for sensor and master cylinder including fitting and VAT.

Im glad you got it fixed.

Im having the same problem with my 02 I took it to the dealer and they changed the brake sensor and it helped for a couple of weeks but its doing it again now so back it goes

I have the same problem,

Could you send me any photo about the location of that sensor?

thank you!!!!