M35 Attesa Ets "pressure Switch" Problems

[zei20l]

actually its probably not safe to drive the car without the pump in the car. the AWD system relies on the fluid being there to continue to lubricate it

i only know of 1 other car that needed a full pump change, and he bought my spare pump assembly

[slippylotion]

He assures me it's fine to drive as the clutch pack has spring pressure to always have it engaged with %5 load so it doesn't need the pump to supply minimum pressure. Isn't the clutch pack in its own oil in the transfer case? I think that's the only part that would always need oil.

I would have thought with other guys having the pressure switch fault they would have looked into it. He said the longer you leave it the more damage it does with the pump chewing itself out. In this case it's about $2k to exchange.

He does all the work for Northshore and many other dealers Aus wide plus retail customers.

Edited June 21, 2012 by slippylotion

[barnze]

To stop the 4x4 light from coming on at start up i flick the switch into Synchro then switch it off once car is running. 4x4 light never comes on after doing that. Not a fix but handy to know.

[slippylotion]

Funny I've been doing that also. Still no good for the pump long term if you want it fixed cheaper.

[Stagea Gazza]

To stop the 4x4 light from coming on at start up i flick the switch into Synchro then switch it off once car is running. 4x4 light never comes on after doing that. Not a fix but handy to know.

Interesting, I've never tried that. I'll definitely give it a try.

I did a flush a couple of years ago when the light first starting coming on - but I'll give it another go.

[slippylotion]

Just keep in mind it doesn't fix the actual problem.

[ChrisB]

When I leave my car parked on my drive way with the engine running a can hear a chirp about once per minuite. I thought it was something to do with the little servo motor on the HICASS. Reading this I now ussume that it is the ATTESA E-TS electric pump on top of the rear diff.

So is the chirping normal or is it something to be concerned about. In the 4 or 5 months I have owned the car the 4WD light has come on about half a dozen times. It will happen about a minuite after start up after reversing out of a parking space and sitting for a while before pulling away. The only way to clear the light is to restart the car. it has not done it now for about 2 months so i assume its OK.

Should I think about changing the ATF fluid in the pump? How about the NS-ATF in the clutch pack. I read that the Pump only pressurises the clutch pack and the pump fluid does not mix with the clutch fluid.

On another note, I tried out the ABS the other day and I noticed that after hard braking the ABS pump makes a wierd noise like a chirping note that lasts a second or two. is that normal?

[slippylotion]

You would really need to see what codes it has thrown as to if there's a problem or not. The system will activate the pump randomly to keep the set pressure but it's usually for a few seconds and not just a quick chirp. You can usually here it at work when you first start the car as it needs to build the set pressure again so the attesa is ready to act upon slip. If its just a quick chirp on start up you may have an issue with the pressure switch. It looses the coating on the solenoid rod inside the pressure switch and starts to randomly stick on or off. Thats why if you leave it too long it damages the pump as it ca stick on. Sorry for my lack of technical description.

[spoolin12]

Let us know how it goes in the end.

I have been having this issue since I got the car.

[slippylotion]

Will do. Plan to remove the pump assembly this weekend and send it off Monday, weather permitting. He said only couple day turn around.

Edited June 21, 2012 by slippylotion

[Tommy Kaira RL]

The pressure switch is between pin 3 and 6. If you have a look at the diagram I would say if the motor is cutting out then it has got pressure and its cuts the motor. The top right of the diagram is the motor circuit. there is a motor relay an actuator relay and a ETS solenoid. You could try putting constant 12v onto pin2 of the motor and see what happens.

I also have this in english but its too big to upload.

[slippylotion]

Thanks brad I'll give that a go tomorrow. I remember though when I checked voltage at that plug with car off and running it only has 4.7volts, Ryan's had the same. Will 12 volts damage anything?

So can I earth out pin 6 on the 4pin plug at the pump to see if that activates the pressure solenoid to see if it does stick? Wiring and wiring diagrams aren't my strong point ?

Edited June 21, 2012 by slippylotion

[Tommy Kaira RL]

]Yes I would say that is ok to short pin 6 to earth on the motor unit at the back there is 2 plugs by the look of it. You should be able to trick the relays as well. Then if all the hard wired stuff works then it could be the control unit itself.

This block/logic diagram might help if you could translate it

[slippylotion]

Cool thanks I test it tomorrow.

So 12 v on the pump is safe seeing as it seems to I ky get 4.7?

[Tommy Kaira RL]

Thanks brad I'll give that a go tomorrow. I remember though when I checked voltage at that plug with car off and running it only has 4.7volts, Ryan's had the same. Will 12 volts damage anything?

So can I earth out pin 6 on the 4pin plug at the pump to see if that activates the pressure solenoid to see if it does stick? Wiring and wiring diagrams aren't my strong point

I dont know exactly what plug you measured 4.7v at. It might be your measuring across the contact and have the motor or solenoid before the earth which would cause a volt drop. Did you measure the plug from each pin to earth with it disconnected. I cant see anywhere where there should be 4.7v. There is only 12v ign and 12v bat

[slippylotion]

Ah there's my wiring skills at work. I just measured across both pins 1 & 2 on the body loom side.

[Tommy Kaira RL]

Ah there's my wiring skills at work. I just measured across both pins 1 & 2 on the body loom side.

in that case you were just measuring the volt drop across the motor. At least you proved there is a circuit there and its the same as another one.

[slippylotion]

Well just pulled out the pump assmb to send off monday. nice easy job taking only 30mins and most of that spent getting tools ready and car on the ramps.

Fingers crossed its only the pressure switch to make it a cheap fix.

[ironpaw]

Sweet. Keep us posted...this guy in Sydney is gonna make some $$$ soon...

[pomnz]

The Service Manual talks a lot about the 圧力SW this being the pressure switch, says the below about testing it:

(Bing)

E-TS actuator

Pressure switch

Unplug the connector, 3 to 6 to check the continuity between the terminals No..

When the accumulator pressure in vacuum

Less than approximately 2.6 MPa {27.0 kg / cm 2}: continuity and

When the accumulator pressure increase pressure

Approximately 3.8 MPa {39.0 kg / cm 2} below: continuity and

See also: • E-TS actuator motor stops immediately after is the アキュームレー

THA pressure is high, no conduction.

• Increased pressure when is the actuator motor when the decompression

And when the actuator motor when.

E-TS motor

• Unplug the connector, plus the battery voltage between pin 2-1

Check out or the motor drive.

Note: to prevent motor overheating not voltage more than 5 seconds

It.

(Google translate)

E-TS actuator

Pressure switch

Remove the connector, check for continuity between pin 3 to 6.

Reduced pressure when the pressure in the accumulator

Continuity: In the following about 2.6MPa {27.0kg/cm2}

圧時 increased pressure in the accumulator

Continuity: In the following about 3.8MPa {39.0kg/cm2}

Note: Immediately after stopping the motor actuator Akyumure • E-TS

There is no high pressure conduction target.

• and an increase 圧時 is when motor actuator operation, decompression

And stop time is when the actuator motor.

E-TS motor

• Remove the connector, when the battery voltage is applied between pin 1-2

Check whether the drive motor.

CAUTION: To prevent heating of the motor, no voltage is applied to at least 5 seconds

Thing.