troubleshooting cruise control

Chriss · Post by **Chriss** » 10 Jan 2011, 05:07

Can anyone recommend a troubleshooting approach for the cruise control on a 1996 850? The cruise section on the PDF manual addresses a 1995 model with the on board diagnostic unit. I don't have that on the 1996 and after replacing the brake pedal switch I am not sure where to go next in a methodical fashion.

I would appreciate any insight you might be able to offer.

Thank you,

Chris

Post by **Ozark Lee** » 10 Jan 2011, 05:20

VOL-FCR with a VAG-COM OBD to serial cable will go a long way since you can actually retrieve the codes and run the diagnostics. That said, since you were working on the brake pedal switch, that is where I would start. The method to reset the switch is the same on your '96 is the same as the '95 that is detailed in the manual. Beyond that the line under the battery tray can crack and leak.

...Lee

Post by **jblackburn** » 10 Jan 2011, 07:08

There are two brake pedal switches - one that has a vacuum line attached to it for cruise, and one with 4 electrical pins on it for brake lights/shiftlock. Which did you replace?

The most common failure point is the vacuum line at the CC pump itself (under the battery tray). I currently have to pull up with my foot on the brake pedal to set the cruise; I was futzing around with the lower brake switch a few weeks ago and must have knocked the other out of alignment.

Chriss · Post by **Chriss** » 10 Jan 2011, 10:55

jablackburn: I replaced the upper switch with the vacuum line.
Lee: You are speaking Greek to me with VOL-FCR etc. Can you dumb it down for the slow witted I'll check the line under the batt tray when the deep freeze lifts of i can work indoors.

Post by **renns** » 10 Jan 2011, 11:43

If the switch is only slightly out of adjustment, you may find that cruise engages properly when the brake pedal is lifted up slightly with your toe. That's an easy test to try next time you're driving the car.

Post by **Ozark Lee** » 10 Jan 2011, 12:07

Lee: You are speaking Greek to me with VOL-FCR etc. Can you dumb it down for the slow witted I'll check the line under the batt tray when the deep freeze lifts of i can work indoors.

VOL-FCR is a diagnostic computer program that reads many of the Volvo specific codes when hooked up with a VAG-COM cable.

...Lee

Chriss · Post by **Chriss** » 10 Jan 2011, 20:30

It it worth the money? The software and cable?

Post by **jblackburn** » 10 Jan 2011, 21:16

I have never used it myself - I have managed to get by with a generic OBDII scanner. If you can not isolate the problem with the cruise control system to one of the usual suspects (brake switch, vacuum line, relay) it might be a good investment. There's a "free" torrent floating around for VIDA out there somewhere.

Post by **Ozark Lee** » 10 Jan 2011, 23:31

Chriss wrote:It it worth the money? The software and cable?

Rumor has it that a cracked version of the software is floating around on Pirate Bay for free. The serial VAG-COM cable is under $20.00 on eBay but it must be the serial cable and your computer must have a serial port for the rumored version to work.

It will also reset the service light which is what I use it for the most.

...Lee

Chriss · Post by **Chriss** » 11 Jan 2011, 07:51

Where would one go to make a legitimate purchase for the software?
Can you recommend a vendor for the software and the cable?

Chris