This is going to sound crazy, but.
I found a scrappy with a pump.
When I got it connected up it was pretty noisy.
So I swapped the motor from it onto my old ABS unit.
Now it runs sweet as a nut.
The original motor feels like it is full of gravel, and is very hard to turn.

The most amazing part is the rough idle is gone, completely.
I can only imagine the motor was so hard to turn, It's start up and running current were very high.
This must have somehow put a drag on the idle. Can't see how though really.
The jerking into R and D is much less, probably back to the way it was, but I am just sensitive to it now. Odd result.
I tested the Black relay, it's definitley working ok.

So I think that's it........for the moment.
I still don't understand the connection between the Idle and the ABS unit. Hey ho it works.
I will know this car inside out by the time this is finished.
Thank you all.


Just as a side note.
My trawl of the internet on this. lead me to a lot of people with a buzzing or gurgling noise from behind the dash.
Some were putting it down to the ABS block.
I had this problem on mine too, it turned out to be the loudspeaker on the back of the instrument pack.
It only happens sporadicaly, no idea what causes it.
It can be identified, as it puts a tiny bit of distortion into the beeps.
Sounds like a gurgle, like air escaping a radiator when you bleed it.

sovereign said:

This is going to sound crazy, but.
I found a scrappy with a pump.
When I got it connected up it was pretty noisy.
So I swapped the motor from it onto my old ABS unit.
Now it runs sweet as a nut.
The original motor feels like it is full of gravel, and is very hard to turn.

The most amazing part is the rough idle is gone, completely.
I can only imagine the motor was so hard to turn, It's start up and running current were very high.
This must have somehow put a drag on the idle. Can't see how though really.
The jerking into R and D is much less, probably back to the way it was, but I am just sensitive to it now. Odd result.
I tested the Black relay, it's definitley working ok.

So I think that's it........for the moment.
I still don't understand the connection between the Idle and the ABS unit. Hey ho it works.
I will know this car inside out by the time this is finished.
Thank you all.


Just as a side note.
My trawl of the internet on this. lead me to a lot of people with a buzzing or gurgling noise from behind the dash.
Some were putting it down to the ABS block.
I had this problem on mine too, it turned out to be the loudspeaker on the back of the instrument pack.
It only happens sporadicaly, no idea what causes it.
It can be identified, as it puts a tiny bit of distortion into the beeps.
Sounds like a gurgle, like air escaping a radiator when you bleed it.

Click to expand...

That will be wet connectors somewhere between the dash and the BECM, investigate before it gets worse.

Datatek said:

That will be wet connectors somewhere between the dash and the BECM, investigate before it gets worse.

Click to expand...

Thats an interesting piece of info, as the random cranking is an ongoing situation, and the solenoid relay is grounded by the Becm to alllow cranking when the key is turned to position 3. So it might have explained both the brake and starting problems.

I thought it worth taking a look at the BECM,
So taking it out it all looks fine no moisture or corrosion.

BECM on the bench. It's huge.



BECM ON bench. by Sovereign125a, on Flickr

Inside all looks clean, factory fresh.


BECM Guts. by Sovereign125a, on Flickr

Car with BECM removed.


Seat BECM Removed by Sovereign125a, on Flickr

It was worth taking it out for a look, didn't find anything interesting under the seats, from the previous owners.

I thought I'd just pass on cure here.

The brake problem wasn't fully cured. It dawned on me that the ABS pump was running continuously. I copped it quickly so the pump didn't do any major long runs. The Black relay coil was fully energised by 12Volts once the key was turned to position 2.

12V is supplied to the coil terminals via a fuse when the Ignition is at Pos 2, the coil is grounded by the pressure switch in the pump, which pulls in and energises the pump motor. When the system is pressurised the pressure switch opens and the Black relay drops out.

I suspected maybe the fuseboard, as the starter relay is right beside the Black relay, Hmm maybe the cause of both problems. The fuseboard was dismantled and looks fine.

Next on the suspect list was the pressure switch, By jumping the Black relay I could get the pump to run and check the pump pressure switch was closing and opening, It was working correctly.

Where was the Black relay getting its ground from?
Well the ansewer was to be found in the Rave wiring diagrams.
What the description didn't tell you was, there is a wire from the Brake ECU to the Black relay ground too. It went to pin 9 on the 18 pin connector under the dash on the brake ECU.

According to rave this pin is " ABS pump relay overide" BINGO.
There are 2 other pressure switches in the abs pump which signal the brake ECU. One of these has failed, the brake ecu thinks the system is in a low pressure state, and grounds this terminal to run the ABS pump continuously, and throws up a dash light.

The pump then burns out.

By cutting the(Black/ yellow stripe) wire at pin 9 on the 18 pin connector, this overide is disabled, and the pump runs to pressure, cutting in and out as required.
Not a perfect fix I am left with a ABS light on the dash, but will have to do for the moment.
I have wired a warning light on the dash to tell me when the pump is running, and it is cutting in and out normaly.

sovereign said:

.......

By cutting the wire at pin 9 on the 18 pin connector, this overide is disabled, and the pump runs to pressure cutting in and out as required.
Not a perfect fix I am left with a ABS light on the dash, but will have to do for the moment.
I have wired a warning light on the dash to tell me when the pump is running, and it is cutting in and out normaly.

Click to expand...

Great bit of detective work...the RAVE manuals are worth their weight in gold sometimes...

Get it fixed properly and don't leave it too long, Brakes are a system you shouldn't feck about with....but as a 'get out of a fix' method...tops!!

Thanks Saint.
It was a bit of a slog.

Here are two pictures of the ABS pump and pressure switch.

Pressure switch Connector with the pump switch drawn in.(motor removed)
The other 3 terminals are the two switches for the brake ECU.
The pressure switch just unscrews from the pump body.
There is a Saab pressure switch, which I believe is identical.


Pump Connector by Sovereign125a, on Flickr

Pressure switch seperated from the body.(motor removed)


switch seperated._2816x2112 by Sovereign125a, on Flickr

The rough idle and jerking into gear which started all this, went away when I changed the ABS pump.

I think what happened really, was I had put a bottle of STP injector cleaner in a full tank, which I forgot about.
This was about half way run through, when I changed the pump.
The car has gotten better as the tank was run through.
So I think that was just a coincidence. It idles smoothley now and no more jerks into gear.
So I think the system just needed a clean through.
Definitley pulling better too.

It's great these cars are so easy to work on, and are actually well built.
Lucky to have great resources like this forum, without which I never would have heard of Rave, much less have the nerve to tackle some of the jobs I have.
Wonder what's going to go next?

sovereign said:

Wonder what's going to go next?

Click to expand...

That didn't take long.

Went to open the back this morning.
Tailgate button pushed in, and stayed in, the tailgate( top bit ) is not closing properly now
Just had a quick look, how does the rear panel come off the gate(bottom part) ?

There is probably a tailgate ECU the size of a shoebox, under the dash that controls it.

sovereign said:

That didn't take long.

Went to open the back this morning.
Tailgate button pushed in, and stayed in, the tailgate( top bit ) is not closing properly now
Just had a quick look, how does the rear panel come off the gate(bottom part) ?

There is probably a tailgate ECU the size of a shoebox, under the dash that controls it.

Click to expand...

Sounds like the spring has snapped, common issue!!

Datatek repaired his with some coiled wire IIRC.....

The lower tailgate inside panel should be held on with screws under the hinged plastic bit then slides down!

Saint.V8 said:

Sounds like the spring has snapped, common issue!!

Datatek repaired his with some coiled wire IIRC.....

The lower tailgate inside panel should be held on with screws under the hinged plastic bit then slides down!

Click to expand...

Yep, length of piano wire from the model shop.

Thanks, Saint and Datatek.
I'll have a look.

Brilliant info, Datatek and Saint.

The spring was broken, in 3 pieces.
But what a simple thing to dismantle and fix, I was expecting springs and levers to be removed.
Two screws and a twist simples.
A piece of yellow foam is now jammed into the top of the switch as a temporary repair.


Here's a picture of the little troublemaker, after a clean up.