T5 Cruise Control Failure

[vrixon]

Hi all,

The cruise control on my recently purchased 2012 T5 LWB Transporter apparently stopped working last year (according to previous owner). I have been unable to identify which fuse is associated with the cruise control (although the link to the missing fuse panel description in this thread was a bonus find - T5 ESSENTIALS (from September 2009), Fuses location,) .

Is there any collective wisdom out there on fault finding the cruise control system? Grateful for all and any help.

[MIG]

Are any warning lights on? It could be a wheel speed sensor or something. See if anyone local with a scan tool can scan it for fault codes.

I don't think there is any additional fuse for the T5 for the cruise; it's all just wired from the stalk to the ECU.

Note: retrofitting cruise was pretty common on the T5s, maybe check if the new wire had been added?

Retrofitting T5 Cruise Control into a T5 with VCDS - YouTube

[BrianJ]

Almost anything can stop it working, a classic cause is a faulty brake light switch, that's the first thing I would check.

[vrixon]

Are any warning lights on? It could be a wheel speed sensor or something. See if anyone local with a scan tool can scan it for fault codes.

I don't think there is any additional fuse for the T5 for the cruise; it's all just wired from the stalk to the ECU.

Note: retrofitting cruise was pretty common on the T5s, maybe check if the new wire had been added?

Retrofitting T5 Cruise Control into a T5 with VCDS - YouTube

Thanks, no warning lights and nothing on my OBDII reader (although it is pretty junk and often missed stuff on my Pug). I can’t see any additional wires in the engine bay … it looks like the ccs is original fit.

Thanks for the link.

[vrixon]

Almost anything can stop it working, a classic cause is a faulty brake light switch, that's the first thing I would check.

How faulty does the switch have to be? As best I can tell the switch is working (lights go on when hear the switch activate).

[BrianJ]

How faulty does the switch have to be? As best I can tell the switch is working (lights go on when hear the switch activate).

I thought this through a bit more after posting, when the brake lights activate that will normally cancel any set speed, so for it to prevent the cruise from working the stop lights would have to be stuck on (unlikely).

I have the factory cruise control on mine, about five years ago it got a fault where if I was on the highway and put the left blinker on to move into the left lane the cruise control would cancel. It turned out to be a broken wire in the blinker stalk that carries to current for the cruise ON switch. So sometimes when I turn left the wire would disconnect, and in that case the light on the dash would go out like it wasn't on. In the case of applying the stop lights to cancel the cruise the light on the dash stays on, just the set speed cancels.

I am assuming that when you move the cruise ON switch to ON, you don't see a light in the speedo. This means a loss of power as you have indicated it could be a fuse or a broken wire in the blinker stalk. If the light in the speedo comes on but you cannot set a speed that holds, then it will be a signal from one of the things that can cause a cancel.

By the way, the solution for mine was an entire new replacement blinker and wipers assembly installed by Austral Motors at Newstead for a mere $500 approx.

[vrixon]

I thought this through a bit more after posting, when the brake lights activate that will normally cancel any set speed, so for it to prevent the cruise from working the stop lights would have to be stuck on (unlikely).
...
By the way, the solution for mine was an entire new replacement blinker and wipers assembly installed by Austral Motors at Newstead for a mere $500 approx.

Thanks for that, all makes sense. I see NOTHING changing when I switch the cruise control on/off so your assessment that it is not getting power seems to be spot on.

My "go-to" VW bloke here in Canberra is not taking on any more customers (despite my previous custom), so I will start shopping around for someone with the right skills to diagnose this properly (I have had poor experiences with the dealers here).

[BrianJ]

The light that should come on when it is turned on is in the 10 o'clock position of the tacho meter, on my beach that is the left and the speedo is the right. This video descibes a fault similar to what mine had and also shows where the light comes on in the tacho if everything is working. 2003-2009 VW T5 Transporter intermittent cruise control - YouTube

As someone mention above in this thread, if the cruise had been retro fitted then its anyone guess what the problem might be or whether the light has ever come on.

This diagram here: Fuse Box Diagram Volkswagen Transporter (T5.1; 2010-2015) says that the power fuse for your model in SC9

Good luck.

[vrixon]

The light that should come on when it is turned on is in the 10 o'clock position of the tacho meter, on my beach that is the left and the speedo is the right. This video descibes a fault similar to what mine had and also shows where the light comes on in the tacho if everything is working. 2003-2009 VW T5 Transporter intermittent cruise control - YouTube

As someone mention above in this thread, if the cruise had been retro fitted then its anyone guess what the problem might be or whether the light has ever come on.

This diagram here: Fuse Box Diagram Volkswagen Transporter (T5.1; 2010-2015) says that the power fuse for your model in SC9

Good luck.

Thank you so much for that … explains a lot and that fuse information is GOLD. Will check SC9 first thing tomorrow and let you know what happens. Bit disturbing if the 30A fuse has simply failed … or it will be an interesting short to isolate

[BrianJ]

Isn't that 30A SB9, SC9 the lower one is 5A and called 'Cruise control system switch'.