1992 Cadillac Deville - ABS Light

[tony1963]

How do you get codes out of the ABS unit on this car? Some say it stores no codes others say that you have to have the GM scanner.

The Solus software has the ABS as an option but it shows no codes.

Thanks!

[Crusty]

How do you get codes out of the ABS unit on this car? Some say it stores no codes others say that you have to have the GM scanner.

The Solus software has the ABS as an option but it shows no codes.

Thanks!

Check it the "Cadi" way.

Ign on Eng off.

Press and hold the OFF and WARMER buttons together on the heater/ac controls.

On the driver information display, you'll get all segments displaying and at that point it has entered diagnostics and you can release the two buttons.

It will then begin displaying all the codes on the vehicle, system by system. write them down quickly as they scroll through.

When it finishes displaying codes it will ask you if you want to enter into ECM-? or BCM-?..... At this point simply turn the key off until you read up on the "On-Board" diagnostic system.

You can repeat the Ign on Eng off, press and hold OFF and WARMER, hold to segment display, release buttons, watch the codes scroll through again if you didn't get them all written down the first time.

You can do this as many times as you need to in order to write down ALL the codes the vehicle has stored.

[tony1963]

Thanks for that tip! I just went out and ran the procedure and got code E52 only.

I'll have to do pinpoint tests, I guess.

[Witsend]

On the driver information display, you'll get all segments displaying and at that point it has entered diagnostics and you can release the two buttons.

It will then begin displaying all the codes on the vehicle, system by system. write them down quickly as they scroll through.

When it finishes displaying codes it will ask you if you want to enter into ECM-? or BCM-?...

Way back in the late 80's- early 90's Cadillac almost succeeded incorporating the Tech 1 scanner into the vehicles themselves . If they had succeeded and all other manufactures had followed suit, by now there might not be any aftermarket scanner companies in business today.

[Crusty]

Well, I may have mislead you. Sorry
Some years and models will get you into ALL the modules on the vehicle but this one may not allow access to ALL modules.

The E52 is just a PCM memory reset code (usually due to battery disconnect)

You'll have to see if you can get your scan tool to communicate.
Try identifying the vehicle as a 1991 or a 1993 .

When you go through the code checks take notice how the on board code check cycles through.
sometimes it scrolls through all the modules.
If you want to answer yes or no you push the temp button up or dow.. sometimes you push the fan speed up or down.
HTH

[tony1963]

I'll try this again. I just recall that when I pressed OFF and WARMER together it lit up all of the LCDs and then gave code E52. I was not sure how to advance to the next series of codes.

Do you have more information on that?

[Witsend]

you tube maybe worth a look

https://www.youtube.com/watch?v=x7_llsru9vA

My guess is you cant do ABs without a Bidirectional scanner from diagnostic connector

[tony1963]

Well, as it turns out, the Snap On scanner can and does connect to the ABS system via the OBD I diagnostic port. I was able to access it using both the Solus and the old MT2500.

Problem is that it does not show codes. I went back to Alldata and think I have figured this out. There is a trouble chart for this condition, ABS light on constant and no codes. The primary cause is either a blown fuse or low fluid level in the pump reservoir.

The car did have very low fluid in the master cylinder reservoir, low enough to trip the light. I'm going to start with replacing most likely the rear shoes and front pads since low brake fluid is a sign of severe wear. Then, I'll vacuum bleed the whole system.

I'll let you know how this goes. Thanks for all of the direction.

[tony1963]

Final Diagnosis

I ended up using Alldata and went through the pinpoint test when the ABS light is on, but no trouble codes.

Turns out that the brake fluid switch on the ABS reservoir (which is gravity fed by the master cylinder reservoir) is defective. The reservoir is full but the switch is open. Jump the wire to the fluid level switch and all is well.

I'm going to replace the ABS reservoir and it appears that parts are still available.

Wow. After 23 years, the system still works!