Abs light on, brake light on intermittent

[doylee4693]

I have an 03 tahoe throwing abs light and intermittent brake light. The abs module was rebuilt about three years ago. Its saying its got a front left wheel speed sensor problem, wheel speed sensor relay, and electronic control brake module. Does the ecbm code come on for wheel speed sensor issues? Or am I in for yet another rebuild and the pita that comes along with unbolting it? Id like to know before I start throwing parts at it. Thanks for any help!

 

[wjburken]

I have an 03 tahoe throwing abs light and intermittent brake light. The abs module was rebuilt about three years ago. Its saying its got a front left wheel speed sensor problem, wheel speed sensor relay, and electronic control brake module. Does the ecbm code come on for wheel speed sensor issues? Or am I in for yet another rebuild and the pita that comes along with unbolting it? Id like to know before I start throwing parts at it. Thanks for any help!

What are the actual codes you are getting?

Is the ABS light on constant or intermittent like the brake light?

 

[doylee4693]

What are the actual codes you are getting?

Is the ABS light on constant or intermittent like the brake light?

The abs light stays on while the brake light is intermittent. Not sure of the actual number to the code, but if needed I could always truck back to autozone and get it. Everything drives normal, and break lines and fluid were replaced just for safety concerns. The codes were there before and after the line replacement.

 

[Doubeleive]

check the wheel hub for starters if it has play then replace it, if has no play then you can try swapping left & right side sensor's and see if the problem follows the sensor or not. if it follows the sensor, then replace the sensor, if it stay on the same wheel, replace the hub.

 

[doylee4693]

check the wheel hub for starters if it has play then replace it, if has no play then you can try swapping left & right side sensor's and see if the problem follows the sensor or not. if it follows the sensor, then replace the sensor, if it stay on the same wheel, replace the hub.

The front hubs are a year old but are cheapest ebay ones I could find because I planned on trading it in, but finances changed and I kept it. Didnt know the sensors could be replaced, does any sensor for my rpo code work, or does it have to come from the same manufactorer who produced my current hubs?

 

[doylee4693]

The front hubs are a year old but are cheapest ebay ones I could find because I planned on trading it in, but finances changed and I kept it. Didnt know the sensors could be replaced, does any sensor for my rpo code work, or does it have to come from the same manufactorer who produced my current hubs?

Also do you know why the abs module is throwing a code if it’s just a sensor?

 

[Doubeleive]

The front hubs are a year old but are cheapest ebay ones I could find because I planned on trading it in, but finances changed and I kept it. Didnt know the sensors could be replaced, does any sensor for my rpo code work, or does it have to come from the same manufactorer who produced my current hubs?

abs sensors are standard so any brand will work as long as it is for the same make/model/year, you just need to troubleshoot this a bit so your not just throwing money at it.

 

[Doubeleive]

Also do you know why the abs module is throwing a code if it’s just a sensor?

the sensors can go bad it's not all that common but it happens, there could be rust inside the hub causing the magnet to not read right, there could be a broken wire in the sensor harness, really hard to say until you do a little troubleshooting. normally the hub just goes bad the bearings inside wear out and cause the hub to wobble so the sensor can't read correctly.

 

[Doubeleive]

a cheapy wheel hub can go bad in a year easily

 

[doylee4693]

a cheapy wheel hub can go bad in a year easily

ok, good to know. I’m more worried about the abs module taking a crap then I am the speed sensor. The last time was miserable getting it off, as the bolts were rusted because I live in salty buffalo NY. Not sure why the module is showing up as a code tho unless it took another dump.

 

[Doubeleive]

ok, good to know. I’m more worried about the abs module taking a crap then I am the speed sensor. The last time was miserable getting it off, as the bolts were rusted because I live in salty buffalo NY. Not sure why the module is showing up as a code tho unless it took another dump.

the abs will be on if the wheel hub is bad, this is why I said the check the hub& sensor first, once the wheel hub passes self check the abs light should go out, if not then you have a different additional problem.

 

[doylee4693]

the abs will be on if the wheel hub is bad, this is why I said the check the hub& sensor first, once the wheel hub passes self check the abs light should go out, if not then you have a different additional problem.

Ok just gotta wait for a dry day to get the wheel off. Praying it’s not the dang abs computer module. Thanks for your help! Much appreciated.

 

[Doubeleive]

Ok just gotta wait for a dry day to get the wheel off. Praying it’s not the dang abs computer module. Thanks for your help! Much appreciated.

I understand completely, I went thru the same problem myself, stripped a bolt on the module had to have it cut out, pita. went thru a couple used modules then finally had a local electronics technician reflow my entire original module and then it finally worked perfect again

 

[doylee4693]

I understand completely, I went thru the same problem myself, stripped a bolt on the module had to have it cut out, pita. went thru a couple used modules then finally had a local electronics technician reflow my entire original module and then it finally worked perfect again

Yeah Its got a lifetime warranty for it, but that doesn’t cover the work required to get those rusty torx screws off. Im gonna have to get under there with a mirror and some pb blaster before I get too worried

 

[Wylie_Tahoe]

Did not read all the responses, so do not know if already mentioned. These chassis are prone to the front wheel speed harnesses to have the conductor break inside the insulation between the frame and hub. It usually shows its self when turning into or out of a parking lot with just a little break input. The ABS will sometimes cycle and the light will come on. Rolling straight down the road and its all good.

If you know which side is suspect, peel off the split loom from the harness and go down it giving a slight tug every couple of inches. Once you find the spot with the broken conductor, the insulation will stretch.

If got one on my 03 that I need to trace down. im 99% sure this is what it is.

 

[wjburken]

Did not read all the responses, so do not know if already mentioned. These chassis are prone to the front wheel speed harnesses to have the conductor break inside the insulation between the frame and hub. It usually shows its self when turning into or out of a parking lot with just a little break input. The ABS will sometimes cycle and the light will come on. Rolling straight down the road and its all good.

If you know which side is suspect, peel off the split loom from the harness and go down it giving a slight tug every couple of inches. Once you find the spot with the broken conductor, the insulation will stretch.

If got one on my 03 that I need to trace down. im 99% sure this is what it is.

Good point. Have seen a lot of sensors replaced only to find the harness is junk. It helps if you can have an ohm meter hooked up to both ends of the harness and see if you get an open circuit while tugging/flexing the harness. If it is bad, get the new harness and splice it above the frame where the cable is attached to the frame.

 

[drakon543]

id like to mention that out of the numerous junk hubs ive used on my past 2 gm vehicles. it seems like depending on the type of failure with the wheel speed sensor it can also pop a code for the abs module. if it can clearly see some kind of fault from the sensor it will only show wheel speed code. if it cant pinpoint the problem itself as a straight broken wire in the harness it will show both. trouble codes are really only good for pointing you toward a system not the actual problem. as suggested in previous posts further diagnosis would be a great help in us helping you and your wallet will thank you as well.
i believe if you lift up the tires so you can free spin them you can also pull a pulsing ohm reading out of the wheel speed sensor. if you dont get the pulse the sensor is crap. if you get a pulse but its not a steady pulse in the reading you might have a bad sensor or some junk on the pulse ring.