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1994 Fleetwood Brougham, dark Adriatic Blue Metallic
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164 Posts
Discussion Starter · #1 ·
I drive my low mileage 94 Fleetwood once a week on a 60 mile round trip to the golf course. Great car, never any problems. I drove it today and the warning lights in the title are all on and won't go off. Any ideas what's up and what I need to do? Fuse?
 

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1994 Fleetwood Brougham, dark Adriatic Blue Metallic
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164 Posts
Discussion Starter · #2 ·
OK, unfortunately it doesn't seem to be a fuse. There's an underhood 60 amp fuse that protects the ABS/Traction Control/Brake pressure and it appears to be intact/good. Help!!!
 

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12,384 Posts
I would say a failing hub assembly or a loose pigtail connection for said assembly is your root cause.
 

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1996 Fleetwood hearse
1996 Cadillac Fleetwood Superior Coach Hearse Conversion
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187 Posts
Rear tone ring sensor on the axle if you have drums at the rear. The sensor can no longer detect the ring so it disables the ABS. Had the same issue on a 92 F150 many years ago. Sometimes you can clean them and that fixes the issue. Otherwise look for a bad or broken sensor at the wheel hubs or a faulty abs module. Ford had a way to get codes off the ABS system but I don't know about Cadillac.
 

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1994 Fleetwood Brougham, dark Adriatic Blue Metallic
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164 Posts
Discussion Starter · #6 ·
I'm not gonna pretend I know what a rear tone ring sensor is; not a complete mechanic noob but never even heard of that. If that is the culprit would it also set off the Traction Control and the Brake warning lights? I did accidently drive a big, deep curb the day before with the right rear wheel. I wonder if that messed something up.
 

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1994 Fleetwood Brougham, dark Adriatic Blue Metallic
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164 Posts
Discussion Starter · #7 ·
Supposed to say "drive OVER a big, deep curb"... above. This sounds like a possibility because nothing else seems amiss, no weird sounds, no grinding, wobbling, etc., like a bad bearing might make...
 

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1996 Fleetwood hearse
1996 Cadillac Fleetwood Superior Coach Hearse Conversion
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187 Posts
It's simple. There is a ring on the back of the disc for the brakes. It has high points and low points equally spaced all the way around it. The wheel speed sensor is a magnetic pickup which judges what speed the wheel is turning based on the tone ring's high and low points. The sensor sometimes gets metal shavings stuck to it through normal use, even the ones mounted in the top of the axle( if that is how yours is set up). The front ones should be mounted to the back of the disc brake backing plate and they stick through and sit really close to the tone ring. Sometimes things get between them and it damages the sensor or a rock can hit it on the outside and damage it.
 

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1996 Fleetwood hearse
1996 Cadillac Fleetwood Superior Coach Hearse Conversion
Joined
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187 Posts
Supposed to say "drive OVER a big, deep curb"... above. This sounds like a possibility because nothing else seems amiss, no weird sounds, no grinding, wobbling, etc., like a bad bearing might make...
If you have 4 wheel disc brakes, then yes you probably damaged a wheel speed sensor. Yes, traction control and ABS work together as they use the same wheel speed sensor a to determine wheel speed at braking and driving.
 

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96 FWB
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2,107 Posts
As mentioned, the last gen Fleetwood used the 4-channel Bosch combined TC/ABS module. Driving over the curb likely damaged the sensor cable to that wheel. Your OBD-I will show more detail using the Fleetwood's on-board diagnostic panel feature using the Climate Control screen. You would do well to carefully inspect the cable from the metal peg at the tone ring behind the backing plate all the way to its plug end. I have had luck seating the plug end with di-elec greast to restore connection, and another time blowing off the metal dust off the magnetized peg end with compressed air.
 

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1994 Fleetwood Brougham, dark Adriatic Blue Metallic
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164 Posts
Discussion Starter · #11 ·
I know the front brakes are disc because I've serviced them but if I recall correctly, on the 94's the rears are drums. IF that's the case are there similar sensors on them also and if so where and what do they look like? I'm FAIRLY handy and I hope this is something I can do myself. Thanks for all the replies/info so far.
 

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1994 Fleetwood Brougham, dark Adriatic Blue Metallic
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164 Posts
Discussion Starter · #12 ·
OK, I'm showing my relative ignorance here but... is a/the tone ring something separate from the rear ABS wheel speed sensor? I looked up a diagram of the speed sensor assembly and I will check the apparent integrity of all that when I jack up the car and remove the wheel so that's why I'm asking if there is something else (tone ring, etc.) I should be looking for/checking?
 

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1994 Fleetwood Brougham, dark Adriatic Blue Metallic
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164 Posts
Discussion Starter · #14 ·
"It's simple. There is a ring on the back of the disc for the brakes. It has high points and low points equally spaced all the way around it. The wheel speed sensor is a magnetic pickup which judges what speed the wheel is turning based on the tone ring's high and low points." The rear brakes on 94's are drums. I know there's a speed sensor attached to the backside of the drum but, like on the disc brakes, is there a tone ring involved also? I have a diagram of the drum and speed sensor assembly but it doesn't show any tone ring.
 
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