2004 V70 power steering problems

68lemans462 · Post by **68lemans462** » 03 Aug 2018, 18:32

Today my v70 power steering became much tighter all of a sudden. Kind of feels like there is some power assist but not much. Fluid level is fine. I went to the junkyard and grabbed a used pump and installed it. Same exact problem no better or worse. What should I check next? Guessing there are no leaks since the fluid was full. Steering rack? Car has 133,000 miles.

Post by **oragex** » 03 Aug 2018, 19:30

Make sure you use the green pentosin fluid. As for the assist part, look near the rack shaft behind the engine: is there an electrical conector/wire? If so, the electric assist sensor may got faulty.

68lemans462 · Post by **68lemans462** » 03 Aug 2018, 19:51

It has the correct fluid.. Electric assist, eh? Sounds like something to check especially since it happened suddenly. I'll look for it thanks.

Can the elec assist be replaced without replacing the rack? Part number?

Post by **jimmy57** » 03 Aug 2018, 20:23

it is not electric assist.
The rack has a piston on it inside a cylinder. Power assist is putting the pressure on one side and opening return from the other side. If the seal on piston fails it does not allow the pressure to push the piston with the needed force. The reservoir will have pretty violent activity in it if the seal is bad if you watch it while someone steers left or right. If the proportioning valve on rack is the issue then the reservoir won't have much action. Either of these issues requires the steering gear to be replaced.

68lemans462 · Post by **68lemans462** » 03 Aug 2018, 21:37

I'm sure this procedure has been discussed before on this great forum! Anyone have a link to the details on replacing the steering rack?

68lemans462 · Post by **68lemans462** » 03 Aug 2018, 22:03

Also, I believe this car has the speed assisted steering. Any pictures of the differences? This car is the "platinum edition" which was loaded with options and I think I spotted the plug to the solenoid while looking behind the engine on the drivers side. Does it have a blue connector on it? I tried to take a picture but couldnt get one.

Post by **oragex** » 04 Aug 2018, 01:49

68lemans462 wrote: ↑03 Aug 2018, 22:03 Also, I believe this car has the speed assisted steering. Any pictures of the differences? This car is the "platinum edition" which was loaded with options and I think I spotted the plug to the solenoid while looking behind the engine on the drivers side. Does it have a blue connector on it? I tried to take a picture but couldnt get one.

Sorry, I meant speed sensitive steering. Seems to have been standard on R models would be interesting if yours also has it

on a R https://forums.swedespeed.com/showthrea ... e-steering

on a XC90 https://www.volvoforums.org.uk/showthread.php?p=2258094

68lemans462 · Post by **68lemans462** » 04 Aug 2018, 15:24

Yes, mine has it. I looked at the original window sticker and it IS listed. Also spotted the wiring harness.

Post by **oragex** » 04 Aug 2018, 18:17

That would be my first step, maybe a used one from Ebay - look for one that doesn't have corrosion (recently replaced). Good to know about the platinum edition, I was wondering what is the difference besides the color. I have one at the junkyard, I'll look see if it has one

68lemans462 · Post by **68lemans462** » 04 Aug 2018, 21:57

Well, I ended up troubleshooting this today using info I found below. I had no power to the steering control module due to a blown fuse. Fuse #5 in the dash near the door protects the vacuum pump and speed sensitive steering. My vacuum pump is on the fritz and this is what I believe caused it.

https://forums.swedespeed.com/showthrea ... e-steering

just fixed my stiff steering and learned a few troubleshooting tools along the way I thought I would share.

First thing I checked was power to the steering control module. This is the blue with red striped wire coming into the back of the control module. I measured it with a standard volt meter, it should have 12V with the key turned on .

The next thing I checked was the signal coming from the CEM. This is the White wire that goes to the pin labeled CEM on page 48 of the manual posted above. With the control module removed, using a volt meter with the car at 0 MPH the wire will read 12V. With vida I set the CEM to 60km/h and the voltage read 6V.

I then measured the resistance between the pins going to the solenoid, the brown and yellow wires, also with the control module removed . The solenoid measured out at 2 Ohms this seemed low so I ordered a new solenoid. When it arrived I measured the new solenoid to be 7 Ohms.

So turns out the solenoid was broken and once replaced steering is now supper easy, almost too easy. I never figured out how to test the output of the steering control module, but maybe some of these tips will help someone diagnose there system.

PS. No code will be thrown with the servotronic control module removed. There is no communication from the module to the CEM. So it is broken there is no way to tell with a scan tool.