DEM-0001 AWD Not Working

XC70Rider · Post by **XC70Rider** » 20 Jun 2019, 08:14

vtl wrote: 14 Jun 2019, 06:55 DEM connectors are not soldered to the board, just plugged in mechanically. They don't take any abuse, yours may have lost electrical contact.

With the new 80 bar sensor installed it fixed the DEM-0001 but now getting DEM-0007. It's getting no hydraulic pressure reading.

Since it's reading temperature correctly you think it could be an internal connection where the sensor transmits the pressure readings? The outer terminal where the sensor slides into appears in good shape. I've cleaned it several times and applied a tab of dielectric grease.

I'll need to test the pump with 12V. I gave it 9V yesterday but got no response.

Also filled it with new Haldex fluid.

XC70Rider · Post by **XC70Rider** » 21 Jun 2019, 10:21

AWD back and running!

I jumped the oil pump to the battery and heard it running. With VIDA I got a pressure reading so I knew it was not the new sensor nor electrical communication with it. When I took the wire leads out of the oil pump harness connector I noticed how twisted the small harness was. After untwisting it I was able to connect it further into the DEM. I broke the tab on that connector last April.

Next week I’ll cut the oil pump harness off at the JY. I'll remove the connector with a pin extractor to note if the wires or connector need replacing. Being high amperage do you suggest I crimp the wires together instead of solder?

Post by **vtl** » 21 Jun 2019, 21:08

XC70Rider wrote: 19 Jun 2019, 21:01For some reason the sensor isn't getting any pressure reading. It only reads 0Mpa. The Haldex fluid is full. I tried testing the pump with a 9V battery but got no response. Does it need 12V to turn on? The pump current is reading 2.5 to 7amps. Does that verify the pump is being activated?

Healthy motor should consume about 0.7-1.3 amps. And, yes, they all die in about 10-12 years of service. I have an old working one for free if you feel you've paid enough for Haldex diagnosis

Located in Ashland.

XC70Rider · Post by **XC70Rider** » 21 Jun 2019, 21:29

vtl wrote: 21 Jun 2019, 21:08 Healthy motor should consume about 0.7-1.3 amps. And, yes, they all die in about 10-12 years of service. I have an old working one for free if you feel you've paid enough for Haldex diagnosis Located in Ashland.

Thank you for the offer but I got the pump back to life. The short harness wasn't fully connected into the DEM. I broke the connector tab in April so it cannot fully click back. I'll cut a harness at the JY next week. If it's just a bad connector then I'll use a pin extractor and swap them. If the wires need replacing then I'll solder the harness from the JY onto my pump. The solder can handle 1.3 amps.

If they weren't a pain to replace then I would throw in another pump but fixing the connector is much easier.

Post by **Antoine240bk** » 22 Jun 2019, 00:45

A new connector can be found under the ref: Volvo, Seat 1J0 973 702 2-Pin
If you have the pin extractor it should be easy.

https://www.ebay.fr/itm/VAG-Volvo-Seat- ... 1438.l2649

XC70Rider · Post by **XC70Rider** » 22 Jun 2019, 06:21

Antoine240bk wrote: 22 Jun 2019, 00:45 A new connector can be found under the ref: Volvo, Seat 1J0 973 702 2-Pin
If you have the pin extractor it should be easy.

https://www.ebay.fr/itm/VAG-Volvo-Seat- ... 1438.l2649

Just ordered the connector from China.

https://www.ebay.com/itm/VAG-Volvo-Seat ... 2749.l2649

Also getting one with a harness included.

https://www.ebay.com/itm/1J0973702-Elec ... 2749.l2649

Thank you for the tips!

XC70Rider · Post by **XC70Rider** » 29 Jun 2019, 07:52

Not only had to mount the connector but I added 700ml of Hakdex fluid last week to get the pump working. I presumed it was low from not bleeding it.

Well the DEM-007 code came back yesterday. Theres no external leaking and the pump is connected to the DEM.

Didn't have time to check Haldex level before a long a drive. If it is low again then I presume the clutch may have an internal leakage. Any member know how to investigate that? Would it leak into the final drive gear?

Post by **vtl** » 29 Jun 2019, 08:45

Did you ever take the pump off before you added 700 ml? Haldex takes about 800 ml when fully drained, but you have to unbolt the whole unit and drain it.

XC70Rider · Post by **XC70Rider** » 29 Jun 2019, 08:56

Haven't removed the pump since installing new oscillation damper last April. Pump and filter have new o-rings and a new seal for the damper.

If its low in fluid again then I'll fill it up and charge pump alone for several minutes. I'll peak at the DEM to see if the sensor or valve are leaking.

XC70Rider · Post by **XC70Rider** » 30 Jun 2019, 10:15

XC70Rider wrote: 29 Jun 2019, 07:52 Not only had to mount the connector but I added 70ml of Hakdex fluid last week to get the pump working. I presumed it was low from not bleeding it.

Well the DEM-007 code came back yesterday. Theres no external leaking and the pump is connected to the DEM.

Didn't have time to check Haldex level before a long a drive. If it is low again then I presume the clutch may have an internal leakage. Any member know how to investigate that? Would it leak into the final drive gear?

vtl wrote: 29 Jun 2019, 08:45 Did you ever take the pump off before you added 700 ml? Haldex takes about 800 ml when fully drained, but you have to unbolt the whole unit and drain it.

I only had to add in 70ml of Haldex fluid to get the sensor to read pressure and AWD to operate back on June 21st. Sorry for the misprint.

When I get home in a few hours I'll raise her up and also hook up VIDA. I can tell from driving the AWD isn't working now. If still just getting DEM-0007 then I'll check the pump wire connection and haldex level. Hopefully it's the pump connection because fixing a Haldex leak will be more of a headache.