Hi all --

Been lurking for a bit here but first-time poster. Hope you like a challenge, because I have one for you.

A little while back, my car (2004 V70 AWD) was giving me an error message that my tailgate was open when it was not. No big deal, didn't see a reason to fix it.

Then, after a month or so, it resolved itself on its own. Now, as of yesterday, the rear defog stopped working. And then today, my back wiper stopped working. And, judging from my getting stuck in my alleway today, my AWD isn't working either.

I say this because I got my tail end onto dry concrete in my garage while the front end remained in the icy alleyway. The front wheels spun and spun and the rears did exactly zero to help.

So, I checked the fuses in the rear cargo area (wiper, defog, AWD module). All fine. So now what? Harness, maybe? Or is my electrical system dying a slow death from the back on forward? Any advice much appreciated ...

Hi,
in the left rear fender there are electronic boxes influenced by moisture even condensed water. these pcb boards have no lack to protect the small on-board-mounted chips, which are thus at risk. check these.
br tapsa

Great advice, thanks again!

Two separate problems, the defog and wiper are probably electrical and stopped because the wires cracked in the wire bundle at the top of the lift gate. It happens.

When was the last time you had the Haldex system serviced? Did you know that it needs the oil and filter changed regularly, at 50K? It also has a logic board inside that cannot get wet, but that usually sets a code or two when that happens.

I found this online which may explain my AWD problem -- suggests Volvo is barely AWD at all??

http://4x4abc.com/4WD101/volvo.html

I, personally, do not like 4WD. I have seen too many 4WD things in the ditch! The owners give it gas, all 4 wheels spin, and the car then slides down the slope and is off the road.

AWD, on the other hand, may not get you out of a ditch, but it will not put you in one just because you got on the gas pedal.

I have never been stuck with my AWD cars. I have never had to worry about shifting my transfer case stick to enable/disable 4WD. I also never go off road where 4WD is king at low speeds - especially when all for wheels are 'locked'.

The Haldex system generates more than 5% (closer to 25%) at the rear wheels. Volvo also integrates the throttle response with the slip control - when slip is detected, throttle is reduced and braking on the spinning wheel is initiated until slip goes away. IE., you cannot make the Volvo spin out.

Haldex does not respond as fast as viscous coupling, but it is easier on the drivetrain as it does not immediately fully engage the prop shaft when one of the front wheels looses traction. Haldex, in combination with the slip control software, is used by AUDI, BMW, Mercedes, Subaru, and others.

The unit does require maintenance. The transfer (bevel gear) box oil needs to be flushed, the haldex oil/filter, also need to be flushed. There isn't a lot of oil and it does get hot in slipping conditions.

Great advice on the maintenance; as far as I know, this has never been done in the 8 years I've owned the car. With any luck, that will solve the issue, because I have been spinning a lot this winter -- rough one in central Canada -- and may have strained the system as you suggest. Just found it odd with the rears on dry concrete being useless, as the fronts spun at high speed.

I didn't know anything about a Haldex system -- thanks!