2004 XC70 AWD not working

Post by **shiloh51933** » 26 Dec 2018, 05:04

Yesterday I was replacing brake rotors and pads on our 2004 XC70. I do one corner at a time and realized that both rear wheels could spin freely. I did notice recently that my front wheels would freak loose quite easily on gravel but didn't put it together. I hear no noises and have no CEL
Edit;
I should have mentioned that I can't turn rear driveshaft/propshaft by hand, so I'm assuming it's something in the rear.

Post by **precopster** » 26 Dec 2018, 05:51

That's not a lot to go on. Best to scan with Vida. If DEM (AWD controller at rear axle) is offline the CEL isn't lit in any case. If the hydraulic pump has failed the result is the same as a failed DEM.

There are AWD tests you can perform. It's best to search here for the actual operational tests for the rear axle.

Post by **shiloh51933** » 26 Dec 2018, 06:23

precopster wrote: ↑26 Dec 2018, 05:51 That's not a lot to go on. Best to scan with Vida. If DEM (AWD controller at rear axle) is offline the CEL isn't lit in any case. If the hydraulic pump has failed the result is the same as a failed DEM.

There are AWD tests you can perform. It's best to search here for the actual operational tests for the rear axle.

My apologies....
If the pump or DEM has failed I still shouldn't be able to move those rear wheels if the other 3 are grounded right?

Post by **jimmy57** » 26 Dec 2018, 10:15

The AOC AWD system is not active without engine running. The hydraulic pump is not turned on until the engine running data bit is broadcast on network. If you do the same things with eng running and you do not have considerable effort to turn the wheel then there is a problem. The AOC will have a low clutch apply pressure when you are doing the test so you could turn the wheel if you apply enough force to exceed clutch load.
You can also do a very quick trst to see if there is a DEM (awd controller) code(s) by having engine running and then hold the READ button on end of turn sig lever and then push the rear fog light button twice. Then the display in cluster will show checking and then likely "DTCs IN VEHICLE" Then pushing the READ button will scroll through the list showing "xxx CHECKING", "xxx READY", or 'XXX DTC SET". checking means it has no DTC but the diag sequence is incomplete, usually has to be driven for this to turn to READY. Ready is no dtc set. You can't see what the code is but if it has no DEM DTC then the temp/pressure sensor is not faulty. No dtc doesn't mean you are in the clear as the coupler sleeve between trans and the angle gear that drives rear driveshaft could be worn out and the spin by hand

Post by **shiloh51933** » 27 Dec 2018, 05:59

jimmy57 wrote: ↑26 Dec 2018, 10:15 The AOC AWD system is not active without engine running. The hydraulic pump is not turned on until the engine running data bit is broadcast on network. If you do the same things with eng running and you do not have considerable effort to turn the wheel then there is a problem. The AOC will have a low clutch apply pressure when you are doing the test so you could turn the wheel if you apply enough force to exceed clutch load.
You can also do a very quick trst to see if there is a DEM (awd controller) code(s) by having engine running and then hold the READ button on end of turn sig lever and then push the rear fog light button twice. Then the display in cluster will show checking and then likely "DTCs IN VEHICLE" Then pushing the READ button will scroll through the list showing "xxx CHECKING", "xxx READY", or 'XXX DTC SET". checking means it has no DTC but the diag sequence is incomplete, usually has to be driven for this to turn to READY. Ready is no dtc set. You can't see what the code is but if it has no DEM DTC then the temp/pressure sensor is not faulty. No dtc doesn't mean you are in the clear as the coupler sleeve between trans and the angle gear that drives rear driveshaft could be worn out and the spin by hand

It says "DEM not checked
CEM dtc set
DDM DTC set
CCM dtc set
PDM dtc set
PSM dtc set
SWM dtc set

boostedxc · Post by **boostedxc** » 27 Dec 2018, 11:27

I have a controller from a 04 v70

Post by **jonesg** » 27 Dec 2018, 13:43

shiloh51933 wrote: ↑27 Dec 2018, 05:59
jimmy57 wrote: ↑26 Dec 2018, 10:15 The AOC AWD system is not active without engine running. The hydraulic pump is not turned on until the engine running data bit is broadcast on network. If you do the same things with eng running and you do not have considerable effort to turn the wheel then there is a problem. The AOC will have a low clutch apply pressure when you are doing the test so you could turn the wheel if you apply enough force to exceed clutch load.
You can also do a very quick trst to see if there is a DEM (awd controller) code(s) by having engine running and then hold the READ button on end of turn sig lever and then push the rear fog light button twice. Then the display in cluster will show checking and then likely "DTCs IN VEHICLE" Then pushing the READ button will scroll through the list showing "xxx CHECKING", "xxx READY", or 'XXX DTC SET". checking means it has no DTC but the diag sequence is incomplete, usually has to be driven for this to turn to READY. Ready is no dtc set. You can't see what the code is but if it has no DEM DTC then the temp/pressure sensor is not faulty. No dtc doesn't mean you are in the clear as the coupler sleeve between trans and the angle gear that drives rear driveshaft could be worn out and the spin by hand
It says "DEM not checked
CEM dtc set
DDM DTC set
CCM dtc set
PDM dtc set
PSM dtc set
SWM dtc set

Check the fuse by the rear hatch.

Post by **shiloh51933** » 28 Dec 2018, 06:26

boostedxc wrote: ↑27 Dec 2018, 11:27 I have a controller from a 04 v70

You think I need one?

Post by **shiloh51933** » 30 Dec 2018, 07:23

jonesg wrote: ↑27 Dec 2018, 13:43
shiloh51933 wrote: ↑27 Dec 2018, 05:59
jimmy57 wrote: ↑26 Dec 2018, 10:15 The AOC AWD system is not active without engine running. The hydraulic pump is not turned on until the engine running data bit is broadcast on network. If you do the same things with eng running and you do not have considerable effort to turn the wheel then there is a problem. The AOC will have a low clutch apply pressure when you are doing the test so you could turn the wheel if you apply enough force to exceed clutch load.
You can also do a very quick trst to see if there is a DEM (awd controller) code(s) by having engine running and then hold the READ button on end of turn sig lever and then push the rear fog light button twice. Then the display in cluster will show checking and then likely "DTCs IN VEHICLE" Then pushing the READ button will scroll through the list showing "xxx CHECKING", "xxx READY", or 'XXX DTC SET". checking means it has no DTC but the diag sequence is incomplete, usually has to be driven for this to turn to READY. Ready is no dtc set. You can't see what the code is but if it has no DEM DTC then the temp/pressure sensor is not faulty. No dtc doesn't mean you are in the clear as the coupler sleeve between trans and the angle gear that drives rear driveshaft could be worn out and the spin by hand
It says "DEM not checked
CEM dtc set
DDM DTC set
CCM dtc set
PDM dtc set
PSM dtc set
SWM dtc set
Check the fuse by the rear hatch.

Fuse is good.

Post by **shiloh51933** » 01 Jan 2019, 13:29

I was able to get some more information concerning AWD issue.
E000- Control module Communication faulty Communication.
0065- Stop (brake) lamp switch signal outside range.

0103-Pedal Position sensor faulty signal.

0147- Pedal Position sensor signal outside its permitted range.

So it looks like something with the CEM is failed up. Any suggestions?