jcorenman

We have a winner!! Well done! Here's a pic from Theo's site: https://jenniskens.livedsl.nl/Techni...6/MyTip649.htm

rahulsingh

Ohh.. than it could be the normal 5 pin relay that is causing this problem.... The part no. is listed on the relay cover, will try to find the exact relay & update you as soon as I fix this...
Thanks

rahulsingh

Update guys...
so I was able to get an original relay & now with the ignition on, pump works for few seconds & then stops... I believe it is because of pressure build up phase.. than after it I turned off ignition again to check the fuse... Yes fuse is ok.. so it was the normal 5 pin relay who was blowing fuse....
Now next time I turned on ignition pump did not work, so to confirm everything I opened the bleeder screw from PSU unit & found that yes fluid is coming out of it, although not much pressure & once pressure dropped pump starter automatically.. so now it was confirmed that here everything is ok..
Next because of curiosity I tried to open bleeder screw at differential, I loosened the screw & found that no fluid is coming out of it... There is something wrong... I had already checked solenoid ( previously did the resistance check & it was 2.7 ohm with continuity)... Again I checked the solenoid & found the same results...
At same time while I started engine, there was no fault of PSD + ABS....
Car was on the lift so I tried to shift transmission... Than during the shift all fault came back... Although fuse was ok... & At neutral car Seems to be actually at drive... At reverse applied it was actually at neutral... I though maybe adjustment is gone off at transmission, so shifted lever at neutral & adjusted the cable end to neutral at transmission.... Then checked again without any success....
I think it is happening because of PSD problem.... We had done a test drive for this car last week, shifts were all working fine.... Is it possible because of car being on lift ????
Thankyou for staying with me this long...

NoVector

It sounds like you're making good progress! I don't know about the errors you're see while shifting your transmission with your car on a lift. But, if you're not seeing fluid bleed from the slave cylinder, that's not good. It's highly possible that your system has not ran in a long time and therefore your pressure valve and slave cylinder are gummed up with old fluid. That's what happened with mine. Below are a couple pictures that should help.

You can take the pressure valve apart and clean it, but they're relatively cheap so I just bought a new one.

The slave cylinder is very easy to remove... once you remove the pressure line, simply remove the two bolts. It's also easy to take apart. As you can see, my slave cylinder was filled with old cruddy fluid that had dried out. If your cylinder walls are okay, you can buy new seals from Roger (928s R Us).

jcorenman

Yes, pump stops when pressure reaches the point where pressure-switch activates. This can be maybe 30 seconds if pressure is drained or only a few seconds-- or not at all- if pressure is still at the set value.
Agreed, that is normal behavior.
The slave is beyond the solenoid valve, and only sees pressure when the solenoid valve actuates. (I get fooled on this also).
There are two ways to actuate the solenoid valve: 1) Disconnect it, and apply 12v with small jumper wires to momentarily activate it.
I do not advise leaving it activated, it is normally pulsed by the controller and may overheat with continuous activation. An assistant here is most helpful
Or, (2) use a "Hammer" tester or some other diagnostic tester to pulse the solenoid while you open the salve bleeder into a catch-can.
I don't think this can be a PSD problem, it is not connected to the transmission. I believe the auto-shift is a mechanical cable, but unfortunately that is all that I know about auto-tranny's, sorry.

ammonman

Apply the emergency brake and I'll wager the error light goes away. I get the occasional ABS/PSD error when cycling the trans through the gears to ckeck trans fluid level if I don't have the brake set. Bleeding the slave cylinder will require a Hammer or a momentary switch to activate the solenoid valve.

rahulsingh

So today I removed the slave cylinder with pipe connection.... Cleaned it properly & then install it back on differential, later on I tried to bleed the pump manually, applied 12 v to pump & gave 12 v to solenoid for a duration of around 7 seconds .. this time fluid came from bleeder screw on slave cylinder( last time no fluid). So fixed back everything. Now I will not shift gears while the car is on lift.. but with ignition on & engine start, there is no warning light.
my speedometer was not working, but all other gauges were working... So I just did speed sensor resistance check on both front side. My readings were 1679 & 1680 ohm... Which is out of spec ( in wsm it is 600- 1600ohm)
I don't remember exactly... Could it be a concern ??

Cheburator

From memory, your speedo picks up speed from the LHS front ABS sensor. Seeing both of them out at the same time is a bit strange. I would swap them from side to side and see what's what. Just so you know, if your Speedometer is not working, you will still get ABS/PSD error once the car is moving as the PSD needs an input from all four sensors to function properly.

Hope this helps,

Alex

rahulsingh

I am just not sure if it is speed sensor, from where the instrument cluster takes value... It is not written anywhere in workshop manual, not in wiring diagram...

Cheburator

Buddy, you have trust me on this one - I have a 1993 GTS 5-spd and also I have a 1990 GT race car which has GTS running gear inside. When we installed the 5-Spd GTS box in the GT we had to modify the speedo wiring to accept signal from the ABS instead of the original sensor on the back of the diff, reason being that GTS transaxles have an internal cooling pump and lose the hall sensor wheel inside the diff. If you don’t trust me - have a look at your main fuse board. On it there should be a relay which acts as pulse modulator for the speedo. Part number 964.618.221.00

rahulsingh

​​​​​​Thankyou Mr.Chebrator, I appreciate for your explanation, now I am sure that it is speed sensor that gives value for Speedo... Thanks a lot for confirmation..

rahulsingh

This is a wire that confuses me a bit for being speedometer/ temperature sensor wire, I could not find any description for it in wiring diagram as well...( 1993 automatic transmission 928 GTS)...
any idea what is this connection for( already know where it plugs)..

It connects at the rear of differential..

Schocki

It's the connector for the kick down solenoid.

SeanR

Shocki is correct, and it's on the wrong side of the transmission. Should route to the other side and connects on the back side, underneath the reservoir.

skpyle

rahulsingh, see if these photos clarify the kick down solenoid wiring for you:




Brown cable goes to the kickdown solenoid. Black tube is the vent hose for the removed transmission fluid reservoir.




Brown cable branches off the transmission harness above the passenger's side of the differential.




Brown cable comes down and goes over to the kickdown solenoid. (Sorry about the dirt and crud, this is a 'before' picture.)




Brown cable plug that goes into the kickdown solenoid.




Location of kickdown solenoid(black rectangular thing) under the differential, behind the transmission mount, above the metal tube from the transmission pan(with the red plastic plug in it) for the reservoir(not shown here) on the passenger's side.




Brown cable for the kickdown solenoid branching off the transmission wiring harness, down and under to the solenoid.




View of brown cable, plug, and kickdown solenoid with the transmission fluid reservoir not installed.




Plastic coupling nut and O-ring seal for transmission fluid reservoir shown for location reference.




Transmission fluid reservoir and heat shield installed for location reference. Note the brown cable snaking its way at the back right side of the reservoir.