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Scalix Mar 21st, 2019 22:00

S80 AWD issue mechanical faillure
Good evening All,

I have a VIDA message saying mechanical faillure of the oil pump. No pressure actuator sliping (something like that)

2000 miles ago the AWD of the car was working fine on gravel. No idea if the message was already there.

I changed the filter and the oil but still the same DTC message and no AWD.

When the car in P position I can't move the prop shaft or rear wheel shaft.

What can be the problem ? faulty pump ? faulty sensor ?

Thanks for the help.

100K+ Mar 22nd, 2019 00:09

What is the actual DTC code?
You can check whether or not the haldex oil pump is working by removing electrical connector and connecting a 9v radio battery across the terminals.
You should be able to hear the pump.

You can also get live data via VIDA/DICE of some haldex/dem conponents.

As you cant rotate propshaft it would suggest issue is in the Haldex unit/components or the DEM.



Scalix Mar 30th, 2019 13:25

1 Attachment(s)
Thanks for the reply. I was abroad. I will have a look tomorrow.

By 9v battery you mean something like this ?

Attachment 119389


100K+ Mar 30th, 2019 23:20


Originally Posted by Scalix (Post 2508931)

By 9v battery you mean something like this ?

yes. Thats what I used.


jgjones095 Mar 31st, 2019 23:35

What’s your mileage. My xc70 had a knackered pump at 200k
Haldex filter had never need changed since 06.

Scalix Apr 2nd, 2019 13:25

I have 71000 miles. I noticed the AWD stop working arround 70000 miles so I decided to change oil and filter. The oil was black but not too bad. Changing oil and filter didn't solve the problem.

I will try to have a go with the 9V battery

Tannaton Apr 3rd, 2019 12:17

It's likely the pump in the AOC coupling, probably the most common failure of them. You should have an error on the dash.

Testing the pump with a 9v battery will tell you if there have been an electrical failure but not mechanical.

Get the oil and filter changed at the same time as the pump.

Scalix Apr 7th, 2019 17:58

Thanks for the help all.

So i had a look and...

The error code is DEM-P188974

The pump works with the 9v battery and i can reach a pressure of 0.18MPa on VIDA.

I can also activate the pump with VIDA. I can ear it however the pressure goes up to 0,15mpa. The pump start for 2 seconds and stop. This is normal ?

Scalix Apr 25th, 2019 22:51

Any idea ? Or lead so i can have a look at ?


100K+ Apr 28th, 2019 10:44

look here -

issue appears to be pressure switch inside the DEM

Good luck


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