Randy Carter

Getting the red alarm warning per the thread title on the '93 five speed. Is this a big concern? The manual was a little vague. Did a search, nothing there.

Thanks in advance.

NoVector

When was the last time you flushed your PSD (or checked the fluid level) ?

Randy Carter

Flushed and changed about 25k miles/ 3 or 4 years ago. The PSD light still comes on when I spin the tires, at least I'm pretty sure it does.

Cheburator

The light comes on regardless of whether your PSD works. Get it tested with a Bosch Hammer or a JDS Spanner. Also check the obvious - fluid state and level.

NoVector

Hey Randy - Generally speaking, your controller isn’t digging what it’s seeing. Possibly a faulty pump, low fluid, clogged control valve, etc. I’ve been all up in my PSD this past month (rebuilt unit, slave cylinder, control valve…) Hope it’s nothing major. I would start by checking the brake fluid in it and go from there. If it’s low… it went somewhere and hopefully not into your differential through a leaking slave cylinder. If it’s clogged, hopefully it will clear with a flush. You’ll find the OC’s flush procedure with a search. If during the flush procedure you find that you can’t power the pump… crawl into the fetal position as the price tag just went up significantly. If that’s the case, there is a guy here in Germany who will rebuild it. That’s worst case...

FWIW, like cheburator said above, the system is kind of blind. I disconnected A and B (the pump) in the picture and I never received a warning. It wasn't until I disconnected C (the PSD controller connector) that I received the fault. BTW, disregard the blue hose in the picture--this is how the unit was shipped to me after the rebuild.

Randy Carter

Thanks, guys. I'll have it checked with a hammer and check the fluid level.

WallyP

If you lose both differential and ABS, the problem is usually a wheel-speed sensor or, more likely, one of the round multi-pin connectors found at each corner (actually, one on each rear corner, two on each front corner).

Alan

Does the error appear soon after start-up before you are moving (in this case its a failure to presssurize the acculumator) or later after you have started moving (in which case its likely a sensor related issue).

If you haven't flushed if for 4+ years its most likely to be just gunky fluid that needs replacement and the system flushing.

Alan

Randy V

Mine has been coming on lately - I'll take note of when it appears.

Either way, it needs to be flushed, but I have not gotten around to doing it yet.

RKD in OKC

First time the Diff Control OFF warning came on fluid was very dirty and reservoir was leaking.

Second time it was accompanied by ABS warning. The accelerometer under the driver seat came unplugged.

Randy Carter

You got it! Started the car yesterday and left it running; when I came back she was lit up like a Christmas tree.

Thanks, Alan.

Alan

Actually the failure to pressurize caused warning should happen quite quickly after starting - usually within maybe 6-7 sec or so.

Alan

merchauser

BUMP:

for anyone having this issue, alan is correct regarding when the message is displayed. many threads on this topic, but I thought I would add to this one.

a few days ago I started to get this warning about 10 seconds after start up. bosch hammer showed no fault codes. a few months ago I flushed my PSD and forgot to attach the wire clip to the connector on the pump/motor. apparently it had wiggled free. put the wire back in place, secured the connector, and all good.

buccicone

I chased this very issue for months on the ‘90 GT. Turned out to be the controller after checking wheel sensors several times. Flushed the PSD. Found a used one on EBay England. So far so good. Sounds like the issue here is the PSD.

Randy V

Yes, definitely a PSD error code.

A flush may or may not clear the code.