Cruise control intermittant

[BrianJ]

At first it seemed to cut out and the light on the dash would dissappear for a moment when the blinker arm was moved, but after prodding around the blinker arm I cannot get it to turn on at all.

I got an auto electrician to remove the steering wheel and check the wires from the cruise lever but they found nothing wrong. I then got a vag-com printout for the van and it came up with the following:

Address 09: Cent Elect
3 faults found.
00895 - Cruise Control Xwitch (E45)
008 - Implausable Signal - (intermittant)
00905 - Fuse for back-up lamps (S40)
014 - Defective - intermittant
00967 - Left Turn Signals
011 - Open Circuit - intermittant

My question is, which fuse is being referred to as S40
Is it anything to do with fuse 9 in the C fuse box as seen here: http://www.vwwatercooled.org.au/foru...ion-64343.html

9-Fuse -5 A-Steering column electronics control unit -30 J527- Adaptive cruise control unit -J428-

Does anyone know which fuses are involved with the cruise control or anything else I can check?

Thanks in advance
Brian

[4wheels]

Hi BrianJ,
This happened to mine twice (fixed under warranty). Was a while ago, but as I recall, it was something to do with the sensor/switches on the clutch and/or brake pedals (which turn it off when you use them) becoming oversensitive. Initial symptoms were Cruise switching out on bumps, which gradually got worse/more sensitive until I couldn't turn it back on. You sure miss it when it's gone.
BrianR
2007 Trakkadu.

[Umai Naa!!]

Yeah, I'd go with the clutch switch. It's pretty common.

[h100vw]

00895 - Ross-Tech Wiki

Ross-tech wiki

Have a look at the fuse though....

Gavin

[BrianJ]

The problem with the clutch/brake idea (apart from being an AUTO) is that if any of these operate they make the cruise drop out, but the light on the dash would still stay on. In mine the dash light was going on and off, and now it cannot be turned on at all.

Thanks for the Rosh-Tech link, what it describes is what I thought it would be but I have had the stalk opened several times and there are no voltages there at all.

Without a circuit, this is how I think it all connects:
Fuse 9 a 5A connects to the controller via F plug then after going through the relevant circuits 12V or a logic high is sent back to the stalk on the various wires. When the switch is moved on the stalk it connects these signals to ground creating a logic low (0V) which tells the controller what action to perform. If anyone thinks differently for how it functions please let me know.

My theory is that the problem could be that the 12V from fuse 9 does not get into the controller due to a break, or that the controller is faulty. Considering that the controller still works for all other functions that is unlikely but you never know.

If anyone could supply the circuit for this it would be very helpful, its a 2006 2.5 diesel auto kombi beach (same as multivan).

Thanks for the help
Brian

[BrianJ]

Update
After spending another 3hrs trying out a few theories, I can report that my description of how the cruise stalk works is incorrect.
I have found that fuse box C, fuse13 5A goes through the loom and up the steering column to the plug that goes onto the stalks, and from there the blue wire delivers 12V to the common track on the printed circuit board in the stalk so when the switches are connected, a signal of 12V goes to the controller.

I have now temporarily connected 12V from the fuse to the stalk and the cruise burst into life. I then removed the top of the column covers and found the black/blue loom wire and found that there was 12V getting to the plug. This proves conclusively that the 12V blue wire is broken as it goes into the stalk which the wiki link above says is the most common fault and what i suspected in the beginning of this saga.

This leads me to why I paid $88 for an auto electrician to test these wires a couple of days ago and received a report saying that the wires are all ok. This really put me off track because I thought it must be something else.

The biggest problem is that you cannot just work on this to fix the wire without removing the steering wheel and first the airbag which I am reluctant to do. So maybe for now i will run a temporary new wire from the fuse box and solder it in the stalk. If at a later time the arm fails or wears out I can get a new complete blinker arm with cruise switches.

If you want something done right then do it yourself

Brian

[Sunny43.5]

Brian I can not agree more with you , without casting aspersions on all auto electricians there are some who verge on the useless side , I have had so many repair jobs in my industry that were taken to auto elecs for diagnosis only to have the owner ring me and I find the problem quick smart and fix it . One case the owner was told the electronic control unit of his sunroof was gone so the owner called me to check quick as a flash first thing I checked fuses and voila one blown fuse fixed the prob , is it that hard for them to do something that easy and I am NOT an auto elec I only fit ands repair sunroofs .The reason the fuse had blown was a local trimmer had pinched the wire up the pillar a test meter told me the circuit was grounding .