No power brakes on abs 1990

[ryan1225]

My hydraulic pump doesn't turn on and my abs and brake fluid lights are on in my 1990 16v 900 . I pulled the fault codes 1222 (faulty main valve, broken short circuit in the vales wiring harness or faulty ecu. I also got 1233 1243 and 1311 which is all the wheel speed senors eccept the right front, but my speedo still works. So using the repair procedure for 1222 from the last page on http://townsendimports.com/Web/brake_folder/900abscodessbpg1.htm

I've got 3.7ohms between terminal 18 and ground it says it should be 2.5

for the main valve. I figured they are taking about this the Bentley book calls it the master valve. There are no numbers on this plug for each pin.
Does anyone know what the method for the pin numbering. I asumed that the pin I'm pointing at is #1 because it is ground as is the one directly next to it and the townsend's instructions says Pin 18 on the ecu, ground, and in 1&2 on the main valve block are continuous. Which I found to be true in my test. But the resistance between 1&2 on the main valve block is .2 ohms not 2-5.

And pin two and the hydraulic unit are also continuous. So I think just the hydraulic pump went out. I would think even if all my wheel speed sensors were out I would still have power brakes. Would anything else cause it not to turn on? And are these differences in resistances I'm getting a big deal?

[900t]

Sounds like accumilator/pump thing... (the black 8 ball there)

ANTI LOCK and BRAKE FLUID lights are illuminated on dash?

Speedometer gets it's signal mechanically through a cable on the tranny. Even if all the wheel sensors were farked the speedo will work and the brakes will work fine, except without anti-lock action.

Without that running, you basically have no brakes on the rear and very slight braking action on the front. I'd probably still end up be driving the car anyway but you should not!

[ryan1225]

I agree it's definatle not safe to drive. The lights are on even after I cleared the codes. Can I replace the accumilator by itself.

[900t]

Yeah just get one of those black things somewhere. GM used the same Teves system and so did Ford (if you look some of those connectors have a blue oval cast in the plastic). Of course, you don't want parts from a Ford

GM USA used the ATE system from '87-91 on Buicks and
Cadillacs, with the accumulator carrying GM part #25528382 (on the shelf, around $100 delivered from gmpartsdirect.com).

http://www.reatta.net/brakes/brakes_pictures.html

[ryan1225]

Yhea I noticed a ford symbol on the plug I was holding. So I need to fix this acsp (as cheap as possible) If I pulled one of those out of a ford or gm it should work. What about the fault codes on the for the wheel speed sensors. The books says .1VAC at 1 rev pre second. But how do I test them ,with an ac volt meter? I can't even find a concetion in the wire to test at.

[cinemarr]

I have the same problem with my car but the brake fluid light only comes on occasionally. The SAAB mechanic said that is fine but you will probably need a new accumulator.

can you post a pic of the parts you used to pull the fault codes please?