Quote:
Originally Posted by 100K+
My understanding of the system is that the Prop shaft should/will ALWAYS be turned by the car, as it constantly turns the Haldex input shaft.
The Haldex is a mechanical/electronic clutch unit where the rear wheel transmission "joins" the front wheel drive, via the Haldex input and haldex output shafts. The Haldex is controlled by the DEM.
If the Dem "can" recognise that the Haldex input shaft is not turning, it might be able to interpret this as a fault. Below is a list of how to check the DEM unit:-
DEM diagnostics follow this order:
1. With vehicle up in the air, ensure the rear driveshaft is turning when in gear.
2. If the driveshaft is not turning, remove the angle gear and inspect the coupling sleeve between the angle gear and transmission. If the splines are not stripped, replace the angle gear.
3. Check for codes in the CEM for communication faults.
4. If the driveshaft is spinning, access the Differential Electronic Module (DEM). If there is no communication with the DEM, check for power on the Blue/Red wire, ground (Brown and Black wires) and network integrity by checking resistance between the Green and White wire. With the battery disconnected, there should be 60 ohms between the two wires.
5. Check the Active On Demand Coupling (AOC) oil pump for proper operation. After startup, the DEM will apply power and ground to the oil pump and you should be able to hear it run. You can manually apply power and ground to it. If it does not run, replace the oil pump. The oil pump can draw excessive current and blow the fuse for the DEM, causing the lack of communication.
6. Check DEM live data and monitor the AOC oil pressure sensor. Key on engine off reading should be 0.00 (+/-.08MPa). Start engine and recheck. With the oil pump running, pressure should rise to .38 (+/-.08 MPa)
Good luck
Cheers
Bob
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Bob,
I have the same issue with no AWD,I can spin the propshaft freely so I have bought a new splined kit to replace what I hope is my problem,my question is how do I use Vida to check the live DEM data,I've got a working Vida Dice but not experienced enough with it yet to use it properly ? It doesn't throw any fault codes bar for a couple of non related issues,I'd like to try and find out if my Heldex unit is working correctly before I start the job of taking the angle gear off and replacing the spline,if my Heldex unit isn't working right I'd rather not start the job and leave the car in 2 wheel drive.Any help would be appreciated.