Location of the ABS Control Unit 1991 Q45?

[trw2k]

I have searched the forum and the internet and read the FSM for the brake system. It says the control unit is in the trunk by the LH rear speaker.
There is nothing in that location in my trunk. I see the FPCU, the speakers, two square plastic boxes (one with fluid in it which I must investigate) but no ABS control unit.
Is it somewhere else on a 91 Q45?

[Q451990]

It's located above the glove compartment on the 91. I guess it moved in the '94 model year revision?

Unfortunately the '91 FSM isn't available online... Let me know what pages you need and I'll try to scan and post them as time permits.

Heath

[trw2k]

Thanks Heath!

{UPDATE}

Wow, ok, so I dug the control unit out from above the glove compartment ...reeeaalllyy tucked up in there and it is a code 9... 9 flashes.
Is this the motor and relay as it says for the 94's as in the Brake System FSM?
Thinking it might be code I started the diagnosis Procedure # 9. The connection for the control unit on the 91 is different than for the 94.
The actuator connector isn't the same either.

That said the brakes do work but the ABS light comes on when I move 5 feet or so.

[Q451990]

I'm going to guess that one of the two relays under the black box that's part of the ABS actuator is bad. When you move the car a few feet, the ABS self test fails, and the light comes on. Wild guess though... usually they fail stuck closed and you'll hear the actuator running under the hood after you turn it off.

Here's a scan of the page for code 9



click the link and you should be able to zoom it better from Picasaweb.

https://picasaweb.google.com/PropertyPh ... 7281432354

Good luck!

Heath

[trw2k]

Cool!
Thanks Heath!

{Update}

Heath it looks like I need Diagnostic Procedure #8 . According to this page this is for 10 LED flashes and I have 9 flashes.
I really appreciate this.
Thanks
Tim

[Q451990]

oops



https://picasaweb.google.com/PropertyPh ... 7763429714

[trw2k]

Thank you so much!
I checked the motor solenoid relay resistance and it is 55Ω so that looks good but I am not sure where to find the actuator connector to test it.
There is an electrical connection in the motor relay box but it has 3 contacts....any ideas?

[Q451990]

I'm pretty sure they're referring to the electrical connectors that are located near the firewall, lower down on the mounting bracket. I'm working off of memory here, but I know there are some connectors that I had to deal with while replacing my actuator years ago.

They are the typical gray brittle ones that you'll see all over the engine bay.

I would also assume that the relay could fail in a way that the solenoid would still show the correct resistance, but not mechanically close. If you can find another relay it might be worth swapping it in just to see.

Heath

[trw2k]

Cool

I just found a 91 fsm on ebay for 49 bucks ( I just discovered that they can be bought for way less than that!) and bought it...every time I have something to fix on this car I think of selling it but then I fix it and forget about selling it. I have done so many things to it at this point I might as well just keep going...see how many miles I can put on it


Next stop after this ABS light issue is figuring out why the seat position memory lights are not on and working and fix the climate control display light.

Thanks again for all of your help Heath!

[Q451990]

Is the whole climate control display blank?

fix-for-1990-1993-q45-climate-controlle ... 49899.html

Heath

[trw2k]

Great!
Yes sometimes it will come on and stay on for a day and then it won't...really intermittent.
This looks like a pretty easy fix.

Seriously you have been a huge help THANKS!

[Q451990]

Anything to keep another beast out of the junkyard! I think there are more sitting in the pull-a-part than on the road around here.