4wd Relay Clicking At Idle

[keysersoze]

got new accumulator swapped in and the relay clicking has been resolved.

thanks for all previous posts and peoples help.

[66yostagea]

As I have converted to RWD, I was thinking to just disconnecting the relay. Is this OK? Will the system go bonkers and cause other problems?

[DaveB]

Just pull the attesa fuse and remove the front drive shaft

[66yostagea]

I have pulled the shafts out a while back. But can not find a fuse diagram that specifically says "ATTESA" I have several diagrams and all I can see that relates is one that says "4WD under the dash,' and there is an FWD relay in the box under the bonnet.

[DaveB]

Hmm, I used to know its location... I believe it's one of the "electrical parts" fuses under the dash, but i guess pulling the relay should have the same effect.

[66yostagea]

Hmm, I used to know its location... I believe it's one of the "electrical parts" fuses under the dash, but i guess pulling the relay should have the same effect.

I.ll try it tomorrow

[KiwiRS4T]

Just pull the 4wd fuse under the bonnet and probably the one in the fusebox as well.

[66yostagea]

Now the DAYZ is ready to rock I am going to try the fuse removal trick. Will post results.

[66yostagea]

Just disconnected the ticker. All OK.

But not the way to fix a FWD ticker

[Maindog]

So my S2 has had the relay clicking noise since I bought it about six months ago. Started off as an occasional thing that you'd notice a couple of times while driving to work. Lately however it's deteriorated to the point where it'd click every 15 seconds or so, even waiting at the lights. Really noticeable at night as the headlights dim whenever it happens.

After reading up on the issue I sourced a new accumulator which was fitted today (and attesa system bled obviously). Unfortunately this seems to have made the problem worse; once the system is warm it'll click rapidly a few times in a row every so often, and probably clicks once every 10 seconds or so when driving. Pressing the 50/50 torque split button (when stationary) causes the pump to trigger four or five times within a second, which pulls the voltage down enough to reset the head unit. This doesn't happen when the car is cold however; clicking starts once its warmed up after driving a few minutes.

I've checked the battery connection as suggested in another thread (no corrosion at all) and I've replaced a grounding strap on the rear sub-frame that had broken off - this didn't change anything. Car has brand new wheels and tyres too so everything should be the same size. No fault codes according to my ECUTalk hand unit, but not sure if that's comprehensive enough. Certainly no warning lights on the dash at all.

I'm a loss as to what to look at next - any suggestions? Voltage dip leads me to think that grounding might be an issue somewhere?

Cheers,

Ryan.

Edited February 11, 2016 by Maindog

[scotty nm35]

Sounds like there is air in the system, or a leak perhaps? What codes is it throwing?

[DaveB]

Yes could be air in the system. Is the reservoir in the boot full?

Also, there is a bleeding procedure; there's a wire with a jumper in it under the driver's side dash. You just take the jumper out and turn the ignition ON to run the pump constantly. You do this with each of the bleed nipples open, one at a time - be careful not to let the reservoir in the boot get too low. There is one bleed nipple at the front and one at the rear of the transfer case I think. It is listed here somewhere. Lots of fluid should come out when the pump is running. I find it actually takes a good 10-15 seconds to charge up the accumulator when you replace it too, so if the system is not running for more than a fraction of a second at a time something must be up.

Failing all that, I have a complete ATTESA pump assembly (minus accumulator) sitting in my shed if you want it.

[Maindog]

Thanks guys,

Agree it does sound like air in the system, though the accumulator was installed and the system bled by a local mechanic who is pretty much the go-to guy for anything imported (says hes done dozens of accumulators in R32s). I'd be surprised if it was air, but I'll bleed it again myself tonight. Reservoir is full.

The ECU isn't throwing codes, but that's the main ecu not the attesa ecu - is there a different proceedure for reading attesa errors?

Thanks DaveB, I'll keep that in mind if it comes to that.

One thing I forgot to mention is that the 4WD actually works fine. So the transfer case is getting the pressure that it needs which probably rules out the pump itself, though the pressure switch could be faulty. I think the attesa ecu itself can be ruled out too based on the fact that the pump triggers a fair bit trying to keep the system pressurised in 50/50 mode, so it definitely seems to be a response to a perceived drop in hydraullic pressure, rather than the ecu thinking that I'm accelerating when I'm not.

Which leads me to the following theories:

1. Air still in the system/accumulator not charged correctly - easy enough to verify by bleeding it again;

2. Pressure sensor in the atessa pump assembly is not sensing correctly, causing the attesa ecu to think there is less pressure in the system than there is - could be tested by replacing the sensor; and

3. Signal from the pressure sensor is noisy due to bad grounding or noisy system voltage (volt reading on my ECUTalk module isn't anywhere near steady) - I'll verify voltage stability with my oscilloscope tonight and maybe pull a larger battery out of the ute to try to stabilize voltage to see if that helps.

Cheers,

Ryan.

[Maindog]

Bleeding the system hasn't helped unfortunately.

[DaveB]

Of course there is always the possibility that the new accumulator is dead. How does it run with the old one back on, any better?

I have a half-flat one if you'd like to test it. At least it would be better than what you're currently experiencing - if it's the accumulator.

[Maindog]

Yes this had occurred to me lol. It was bought off ebay, looked new and had the seal, document in japanese etc, but there's a probably a lesson in there somewhere. Don't have the old one unfortunately, told the mechanic to turf it thinking I wouldn't need it any more.

Thanks for the offer; I'll take it back to the workshop next week and see what they've come up with for the next round of testing - hopefully they'll still have the old accumulator or at least another one to test with. If not I'll get back to you - might be interested in that pump of yours by then...

[DaveB]

No problem.

[scotty nm35]

I have various parts too if you need something, the M35 usually faults with pressure switch issues, I have a couple of units here needing repair or for parts. Pretty sure they are the same Attessa unit right through.

[Maindog]

Thanks guys. Car is back at the mechanics, said he had a few things to try out and that the accumulator I bought off ebay was definitely a new unit. I suspect it may be a dicky pressure sensor but I'll know more by the end of the day.

[DaveB]

Good news.

It may be a new unit, however, is it actually charged? Only takes a few seconds to swap the old one back in to test.