Rear ABS Reluctor
Thread Starter
Instructor
Joined: Mar 2008
Posts: 148
Likes: 0
From: Rindge NH
Rear ABS Reluctor
...I hope that's the correct term.
I'm chasing an ABS issue. Car is an '89, 6sp. coupe. ABS doesn't work.
The Light comes on after the self test at ~9mph.
Following some tips I've found here and in the FSM, I first did a static resistance check on the wheel sensors. All 4 check out OK using a DVM - approx. 1.046kohms on all 4.
Next I did a dynamic check, again using the DVM, looking for voltage at the sensors. Three of the four generated a voltage. The left rear did not.
Assuming the sensor is good - based on the static resistance check it is - how do I get to the reluctor ring in order to check it/replace it? Is it a separate piece or part of the rear hub?
I don't see much specific reference or pictures.
TIA for the help...
I'm chasing an ABS issue. Car is an '89, 6sp. coupe. ABS doesn't work.
The Light comes on after the self test at ~9mph.
Following some tips I've found here and in the FSM, I first did a static resistance check on the wheel sensors. All 4 check out OK using a DVM - approx. 1.046kohms on all 4.
Next I did a dynamic check, again using the DVM, looking for voltage at the sensors. Three of the four generated a voltage. The left rear did not.
Assuming the sensor is good - based on the static resistance check it is - how do I get to the reluctor ring in order to check it/replace it? Is it a separate piece or part of the rear hub?
I don't see much specific reference or pictures.
TIA for the help...
Melting Slicks
Joined: Apr 2003
Posts: 3,110
Likes: 6
From: Red Sox Nation! RI
The reluctor ring is the toothed ring that's part of the wheel bearing/hub assembly. You'd have to replace the whole hub if something was wrong with the the ring.
You could try tracing the wiring from the sensor back to the harness and module, try cleaning the sensor and reluctor or have someone move the sensor wire around while you do a voltage check. Good to use a little anti-seize in the steering knuckle when you pop the sensor back in, too.
You could try tracing the wiring from the sensor back to the harness and module, try cleaning the sensor and reluctor or have someone move the sensor wire around while you do a voltage check. Good to use a little anti-seize in the steering knuckle when you pop the sensor back in, too.
Thread Starter
Instructor
Joined: Mar 2008
Posts: 148
Likes: 0
From: Rindge NH
I took all my readings at the white 8 pin connector inside the storage well behind the driver's seat. I got a resistance reading from the left side, no voltage, meter on the same pins. I'd assume the wiring to that point is alright.
I'll try changing sides with the sensors, but both of them having the same resistance reading makes me suspect the problem lies elsewhere.
If swapping sensors side-to-side doesn't do it, I guess the next step is a rear hub.
I wasn't sure about he rear hubs. I suspected the ABS stuff was inside the front hubs.
I'll let ya know what I find.
(The sensors seem to be stuck in there pretty good - probably 19 years worth of stuck!)
I'll try changing sides with the sensors, but both of them having the same resistance reading makes me suspect the problem lies elsewhere.
If swapping sensors side-to-side doesn't do it, I guess the next step is a rear hub.
I wasn't sure about he rear hubs. I suspected the ABS stuff was inside the front hubs.
I'll let ya know what I find.
(The sensors seem to be stuck in there pretty good - probably 19 years worth of stuck!)
Melting Slicks
Joined: Apr 2003
Posts: 3,110
Likes: 6
From: Red Sox Nation! RI
If your rear hub isn't loose or doesn't look coroded, I'd keep testing before replacing it. Here's some more info http://forums.corvetteforum.com/show...&highlight=ABS
Instructor
Joined: Mar 2007
Posts: 140
Likes: 1
From: Corydon IN
Hi. I chased an ABS problem like yours for over a year. Just got it fixed last week. ABS light after self test. Code said bad L/R sensor. Sensor was good. I even bought a pin out tester so I could check the circuits.
I finally bought a used ABS module and that fixed it.
I suggest that you pull the sensor that shows bad and look into the hole that it slips into. You can see the reluctor ring. Many times they will have grit and steel bits on them and will cause the problem. Blow compressed air into the hole while turning the wheel. If that is OK I would try a module from Ebay. If you watch you can get them pretty cheap. Mine was $30.00 . You can also have yours rebuilt and updated for about $300.00. I have the name of a place in TN that repairs them. Let me know if you need the PH # & address.
Greg
I finally bought a used ABS module and that fixed it.
I suggest that you pull the sensor that shows bad and look into the hole that it slips into. You can see the reluctor ring. Many times they will have grit and steel bits on them and will cause the problem. Blow compressed air into the hole while turning the wheel. If that is OK I would try a module from Ebay. If you watch you can get them pretty cheap. Mine was $30.00 . You can also have yours rebuilt and updated for about $300.00. I have the name of a place in TN that repairs them. Let me know if you need the PH # & address.
Greg
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Intermediate
Joined: Apr 2008
Posts: 42
Likes: 0
If your rear hub isn't loose or doesn't look coroded, I'd keep testing before replacing it. Here's some more info http://forums.corvetteforum.com/show...&highlight=ABS
cheers
Le Mans Master
Joined: Jan 2003
Posts: 5,858
Likes: 7
From: Santa Maria CA
Just remove the sensor from the knuckle and you can visually inspect the ABS reluctor ring though the hole. It's part of the hub. Do it with wheel removed and rear raised, so you can rotate the hub by hand and inspect all the teeth.
Thread Starter
Instructor
Joined: Mar 2008
Posts: 148
Likes: 0
From: Rindge NH
Getting back to chasing this problem...
Pulled out the rear sensors. The right side - functioning side - has, for lack of a better term, a tab sticking out from the center of the mag pick up which is missing from the left - non functioning - side.
I suppose that would explain why both sides pass a static resistance test but only the right side passes a dynamic test.
Looks like I'll be replacing the left side sensor.
Thanks for the help.
(Oh, and I did see the left side reluctor. It doesn't appear to be part of the hub to me, rather on the end of the drive shaft.)
Pulled out the rear sensors. The right side - functioning side - has, for lack of a better term, a tab sticking out from the center of the mag pick up which is missing from the left - non functioning - side.
I suppose that would explain why both sides pass a static resistance test but only the right side passes a dynamic test.
Looks like I'll be replacing the left side sensor.
Thanks for the help.
(Oh, and I did see the left side reluctor. It doesn't appear to be part of the hub to me, rather on the end of the drive shaft.)
Race Director
Joined: Jan 2008
Posts: 16,028
Likes: 170
From: oregon
Oddly the diaignostic feature of our abs system isn't all that it's cracked up to be. maybe that's why the dealer uses a breakout box. on the rear, here's how i would go about it
1. test for resistance, if ok
2. take off hub and inspect sensor
3. if visual is okay, test for resistance inside the ABS compartment, if ok replace EBCM.
remember, the abs only stores 3 codes even if more are present {rare} the abs codes also have to be hard removed, undoing the battery will not clear them. FSM describes how to do. Many times when the EBCM is just about to go you will get random codes every so often that increase in frequency before you get a code or codes that are simply not right. usually an EBCM will reset the same code over and over if it's dead or dying regardless of fixes made to what the code is supose to be. I actually spent a few weeks studying this system when i had a dead EBCM with trouble codes that; at first i took at face value. There is a relay that fails in there from time to time the longer i think about this. this article will explain how to test the relay i speak of http://www.corvettefever.com/howto/19239/index.html before i forget, clean the ground by your oil filter. the EBCM is grounded there and that area does get a lot of grime.
1. test for resistance, if ok
2. take off hub and inspect sensor
3. if visual is okay, test for resistance inside the ABS compartment, if ok replace EBCM.
remember, the abs only stores 3 codes even if more are present {rare} the abs codes also have to be hard removed, undoing the battery will not clear them. FSM describes how to do. Many times when the EBCM is just about to go you will get random codes every so often that increase in frequency before you get a code or codes that are simply not right. usually an EBCM will reset the same code over and over if it's dead or dying regardless of fixes made to what the code is supose to be. I actually spent a few weeks studying this system when i had a dead EBCM with trouble codes that; at first i took at face value. There is a relay that fails in there from time to time the longer i think about this. this article will explain how to test the relay i speak of http://www.corvettefever.com/howto/19239/index.html before i forget, clean the ground by your oil filter. the EBCM is grounded there and that area does get a lot of grime.
Instructor
Joined: Apr 2007
Posts: 225
Likes: 1
From: Highland Village texas
Oddly the diaignostic feature of our abs system isn't all that it's cracked up to be. maybe that's why the dealer uses a breakout box. on the rear, here's how i would go about it
1. test for resistance, if ok
2. take off hub and inspect sensor
3. if visual is okay, test for resistance inside the ABS compartment, if ok replace EBCM.
remember, the abs only stores 3 codes even if more are present {rare} the abs codes also have to be hard removed, undoing the battery will not clear them. FSM describes how to do. Many times when the EBCM is just about to go you will get random codes every so often that increase in frequency before you get a code or codes that are simply not right. usually an EBCM will reset the same code over and over if it's dead or dying regardless of fixes made to what the code is supose to be. I actually spent a few weeks studying this system when i had a dead EBCM with trouble codes that; at first i took at face value. There is a relay that fails in there from time to time the longer i think about this. this article will explain how to test the relay i speak of http://www.corvettefever.com/howto/19239/index.html before i forget, clean the ground by your oil filter. the EBCM is grounded there and that area does get a lot of grime.
1. test for resistance, if ok
2. take off hub and inspect sensor
3. if visual is okay, test for resistance inside the ABS compartment, if ok replace EBCM.
remember, the abs only stores 3 codes even if more are present {rare} the abs codes also have to be hard removed, undoing the battery will not clear them. FSM describes how to do. Many times when the EBCM is just about to go you will get random codes every so often that increase in frequency before you get a code or codes that are simply not right. usually an EBCM will reset the same code over and over if it's dead or dying regardless of fixes made to what the code is supose to be. I actually spent a few weeks studying this system when i had a dead EBCM with trouble codes that; at first i took at face value. There is a relay that fails in there from time to time the longer i think about this. this article will explain how to test the relay i speak of http://www.corvettefever.com/howto/19239/index.html before i forget, clean the ground by your oil filter. the EBCM is grounded there and that area does get a lot of grime.
Thread Starter
Instructor
Joined: Mar 2008
Posts: 148
Likes: 0
From: Rindge NH
I couldn't find a replacement wheel sensor anywhere!
I had a crazy idea one night, so I sat down to browse through the McMaster-Carr website looking for magnets.
I found item 57315K41 - a 3/8" long x 1/8" wide x 1/8" thick .37lb pull alnico bar magnet for $1.05. Ordered it along with some JB Weld. Pulled the right side sensor and butted the new magnet up against the right side sensor until the magnets repelled (same pole). Marked it. (I'm not sure whether pole orientation matters, but I figured it couldn't hurt). I JB Welded the magnet in the same orientation as the other side using a fillet of the stuff on each side of the magnet as opposed to a bond between the sensor and the new magnet. Again, I don't know if it would have mattered, but it couldn't hurt, right?
End result is I now have functioning ABS for about $10 - as long as the bond holds
Thank you for the replies and suggestions.
I had a crazy idea one night, so I sat down to browse through the McMaster-Carr website looking for magnets.
I found item 57315K41 - a 3/8" long x 1/8" wide x 1/8" thick .37lb pull alnico bar magnet for $1.05. Ordered it along with some JB Weld. Pulled the right side sensor and butted the new magnet up against the right side sensor until the magnets repelled (same pole). Marked it. (I'm not sure whether pole orientation matters, but I figured it couldn't hurt). I JB Welded the magnet in the same orientation as the other side using a fillet of the stuff on each side of the magnet as opposed to a bond between the sensor and the new magnet. Again, I don't know if it would have mattered, but it couldn't hurt, right?
End result is I now have functioning ABS for about $10 - as long as the bond holds
Thank you for the replies and suggestions.
