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View Full Version : Sloppy snow --loss of AWD, antilock brakes+cruise



Rickpro67
01-09-2012, 01:25 PM
2004 XC70 -- SUDDEN FAILURE OF AWD, ABS and CRUISE CONTROL

CONDITIONS: sub-freezing with fresh wet snow accumulating in the wheel wells.

SYMPTOMS: All "engine trouble" lights come on and a warning reads "Brake system failure". Stopping and turning off the car, clearing the snow out of the wheel wells and restarting cleared the "Brake system failure" warning and replaced it with "Anti-skid needs servicing".

Am able to drive the vehicle and all is AOK except:
-no AWD (front drive only)
-no anti-lock braking
-no cruise control

ADDITIONAL INFO: I had exactly the same experience a year ago, which was fixed by the dealer by removing and replacing 2 axles to install 2 new ring gears.

QUESTION: unlike for my first 2 Volvos, I didn't buy the shop manuals for this one. I'll be driving the 120 mi/200 kms to Ottawa for repairs, but would like to be armed with some info. Can anyone tell me why a Swedish (:confused:) car fails like this in "normal" winter conditions? Is there a seal or a guard missing? Is there anything I can do to prevent recurrence? Waiting for the snow to go away is not always an option.....

Thanks,

Rick

goldxc70
01-09-2012, 04:12 PM
Are you sure your AWD is gone? I get the "Brake Failure" message intermittently on my MY 2004 but ABS, Cruise Control and Tachometer readings appear to be the only functions affected. As I'm not doing much driving these days it doesn't bother me too much. I've been told that the ABS rings get gummed up and they need to be blown out with high pressure air.

dpaton
01-10-2012, 09:25 AM
My guess is one of the connectors to or the ABS sensors in the wheel wells is failing due to the abnormal condition - could be a broken ABS ring or a loose axle bolt - all easy to check.

Alternatively, does anyone where the ABS unit (is it the BCM in the wiring schematic?) and yaw sensor is located in this 2004 car so he can check those connectors too?

Forkster
01-10-2012, 11:27 AM
Or your battery is acting up and needs replacement.

Rickpro67
01-12-2012, 01:18 PM
Or your battery is acting up and needs replacement.
Thanks,

The Volvo battery is new and was installed by independent Volvo mechanic just two weeks previously. That could be a clue.......but it appears to be working AOK in all other respects, such as cold weather starting and prolonged operation on two 9-hour trips within the past week.

Rickpro67
01-12-2012, 01:23 PM
Are you sure your AWD is gone? I get the "Brake Failure" message intermittently on my MY 2004 but ABS, Cruise Control and Tachometer readings appear to be the only functions affected. As I'm not doing much driving these days it doesn't bother me too much. I've been told that the ABS rings get gummed up and they need to be blown out with high pressure air.
I don't recall my tach being affected, and I'm sure I would've noticed that in 18 hrs of driving. My cruise was definitely not working, and my anti-skid service indicator was on, so I must assume that was out. I am absolutelly certain that my AWD was out at times, but I have no way of knowing if it kicked-in intermittently -- for sure, I didn't notice it.

Rickpro67
01-12-2012, 01:36 PM
My guess is one of the connectors to or the ABS sensors in the wheel wells is failing due to the abnormal condition - could be a broken ABS ring or a loose axle bolt - all easy to check.

Alternatively, does anyone where the ABS unit (is it the BCM in the wiring schematic?) and yaw sensor is located in this 2004 car so he can check those connectors too?
Thanks for those possibilities to check out I'm driving the 200 kms to Ottawa tomorrow to get it serviced. I'll let everyone know what the shop finds/does (but not 'til next Tuesday). Thanks!

Rickpro67
01-14-2012, 05:22 AM
I'm not sure that I'm posting this correctly, but this is a promised update to my 12 Dec post. Thanks for your inputs to date!

Yesterday, my Volvo mechanic was able to repair the ABS but I was told that I need a new differential module which costs $1900 and isn't even available in Canada. He's now trying to find me one (used?) and I'll be calling him on Monday for results.

I was told that the reader returned a permanent fault (or failure?). What I don't know is "is this measured/read at the module itself, or through a wiring system?". In other words, could the reading be the result of a connectivity problem, only?

At a related thread, I noted advice that the pressure sensor on/with the differential module should be addressed first.....

I'd appreciate any advice on how to proceed.

Astro14
01-14-2012, 06:31 AM
Responded to your other post...

Read up on the Haldex...and don't have your mechanic just throw parts at it, new or used...he needs to really trouble shoot it, not just rely on codes...throwing parts at a problem, based solely on codes, is inefficient and can get really expensive...