Brakes problem
2001 Cadillac Deville V8 Front Wheel Drive Automatic 32000 miles
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The ABS, Brakes, and Traction warning lights had come on occasionally, but now remain on all the time. It's never one, or two of the lights, but always all three that stay on. I don't know how, nor have equipment to retrieve codes. What would be the troubleshooting steps I need to take to isolate the problem? Thanks....

In this case, you are going to need a scanner that can watch the speed sensors results in real time. Not to say it is a speed sensor at fault, but often it is. May be a wiring harness as the next most common fault.

It may be worthwhile to pick up a code reader or have AutoZone check the codes. It may or may not have one in there.

When one or more sensor signals drops out, the computer thinks thinks the car is into a skid or at least knows that all four wheels appear to not be going the same speed. When it sees this it throw the ABS light and sometimes the Red brake light as in you case. The Traction control is also disabled.

You can do a visual inspection of the harnesses to be sure they look good and are attached. IF you have any wheelbearings going bad, most notably shown by a hum or play in the bearing, that may direct you to the source as well as the the sensor is part of the bearing on those I believe.

Thanks for the info. I'll pursue that direction.

Jimmiez wrote:

Thanks for the info. I'll pursue that direction.

also Service Writer he needs to ck the brake fluid it can cause this prob, pads may be warn enough to have it come on

Thanks Buzzsaw, fluid and pads are fine...had them checked about 4 months ago. No audible bearing noise. I did a visual on the leads and they look fine. Removed/cleaned connector terminals at each wheel with LPS in case they may have been dirty. No help. Will a scan determine which sensor, if any is the problem?

A scanner that is capable of reading the wheel speed input will. It will show what the computerfor that system is being told by the speed sensor.

Service Writer wrote:

A scanner that is capable of reading the wheel speed input will. It will show what the computerfor that system is being told by the speed sensor.

scan your codes, off and down on your mode button with the key in the on position, get a peice of paper to write them down, look in the message center for the codes, like Service Writer says it might be the VSS or a wheel sensor

Thanks Service Writer and Buzzsaw.
Autozone scanned the engine codes and there were none. This issue never showed the MIL, just the three warning lights. The 3 lights stay on when the vehicle is stopped (obviously all wheels going the same speed)...is it correct to assume there is NO signal from one of the wheel sensors? If so, can wheel sensors be jumpered one at a time to determine which may not be sending a signal? How? As I said earlier, I don't have a scanner. Where I'm going here is to determine if I can diagnose which sensor is bad and can I (a better than average though untrained mechanic) replace the wheel bearing assembly?

Jimmiez wrote:

Thanks Service Writer and Buzzsaw. Autozone scanned the engine codes and there were none. This issue never showed the MIL, just the three warning lights. The 3 lights stay on when the vehicle is stopped (obviously all wheels going the same speed)...is it correct to assume there is NO signal from one of the wheel sensors? If so, can wheel sensors be jumpered one at a time to determine which may not be sending a signal? How? As I said earlier, I don't have a scanner. Where I'm going here is to determine if I can diagnose which sensor is bad and can I (a better than average though untrained mechanic) replace the wheel bearing assembly?

scan your codes like I asked to on the last reply, caddies dont need a scan tool, they have self diagnostics. If lights are on you have codes

Thanks, Buzzsaw. The DIC doesn't show any messages that any systems are malfunctioning. The brakes work fine, although I've not been in any driving conditions that would activate the ABS. What if the brake control module itself is bad and sending erroneous signal, then the ABS and Traction Control systems drop out because the brake warning light is on?