ABS rear cable repair or replace?

[Joseph]

Hello,

So, I have an issue with my 2008 Buick Lucerne. Im quite lucky as my neighbor has a diagnostic pad from snapon and it shows that my right rear ABS has no signal. This is what lead me to watching the great videos here. Infact, I was so inspired by the videos that I think I have watched about 3/4 of them all! So, I decided to tackle this problem on my own. I do have alot of electronics experience but not in cars. So, In listening to my neighbor and with his experience and advice I replaced the right rear bearing hub. I invested in some tools also. I think Harbor Freight is fantastic. Picked up what I would need but I am on limited funds. My best investment to date has to be the impact drill – 18volt chicago made. I know its not the best but cannot afford the DeWalt. Back to the problem. After replacing the hub I was still not getting any signal so I started tracing the lines underneath my car back and I really didnt have to go far. Seems Both rear abs sensor cables terminate into a 4 pin connector on a master cable that I assume leads up to the engine compartment. Well, Evidently something I ran over snagged on the right rear cable and tore it out of the connector on the sensor side. The connector and left rear abs line look fine. The right rear wires are pretty much mangled and torn away from the connector. So, I cleaned them up bypassed the connector and spliced them into the main line. I left plenty of room on the main cable in case I need to reconnect it.

Now after reseting the abs system I get an error for the right rear that the signal is erratic. Evidently noise on the signal is being introduced thru my solder job? A few things come to mind – 1. The cable was stretched when it broke and there are more issues with it 2. The type of wire used on the sensor side doesnt like to be soldered because of the type of wire they use.

So now I am thinking of how much it will cost to buy a replacement cable and harness for both back sensors. It appears that the right rear and left rear cables are joined at the connector to the main run. Its not like I can replace one side only.

Has anyone had to do this before? I have been looking but cannot find the cable/harness online yet. Any thoughts are sure appreciated in this matter.

coffee

Topic

[Austin]

specify cable. Are you talking about your wheel speed sensor?

[Joseph]

Yes, Its connected to the bearing hub as the hub is a sealed unit with abs sensor built in.

[Austin]

okay and I know you probably said it, but the wires were ripped out of the connector at the connector on the hub? Or did they snag farther down maybe half way down the wiring harness? As a tech we use Rosin-Core solder. I would ask myself if the wires that were snagged, yanked the sensor so hard it broke the sensor. I would double check your wiring, make sure your connections are correct and make sure they are routed correctly and see if it comes back. If it does, I would just replace it. The new one should come with a new harness anyway.

[Joseph]

The spot where both back cables join to a “Main cable” right in the middle of the underneath of the car in front of the back tires. The left rear (2 wires in the cable) ripped out of the connector.

On my car both rear speed sensor cables terminate into a 4 pin connector. On the other side of this connector is a what appears to be a main run up to the engine compartment. The 4 pin connector is located underneath the car, In the middle.

*** The connection from the right rear speed sensor cable was ripped out of the connector and missing a few inches. Not enough to possibly get them put back in.

[Austin]

I would also disconnect the sensor at both ends, and check for continuity on ever wire by front probing, don’t back probe. You want to make sure you have continuity on the front of the connector on each side. If you have it then you know it’s a sensor issue. I would also make sure my connectors are full connecting and check for continuity on them. As in: Wire – connector – connector – wire. continuity check here —->>—- and here. That way you know signal is making it through the connectors with no issue.

[Joseph]

Well, I know the signal is having issues getting thru the cable. I know the cable is bad – got yanked out and mangled when whatever hit it.

RR/LR Speed sensor cable –>4 pin connector —> front of car

Right rear speed sensor cable is broke from 4 pin connector. I dont know if its possible to reconnect it. I basically had enough room to bypass the 4pin connector (for the right rear speed sensor cable) and splice into the main cable going to the front of the car. Now sensor is being detected but the signal is “Erratic” according to the scanner. Right rear hub is new and tested good. Would you try resoldering or just replace the whole darn RR/ LR cable assembly?

Thanks for your patients on this.

coffee

[Austin]

Not a problem that’s why im here.Does each wheel have it’s own connector as in 2 connectors plug into the 4 pin or is it all wiring from left and right go into one connector? instead of soldering this time, I want you to try and use butt connectors. Make sure you crimp them good and have good continuity. Double check your wiring, crimp them down and then see what happens. If it keeps happening I would replace the wiring.

[Joseph]

Thank you.

Each wheel has a connector with two pins in it. Thus, Each cable has two wires. However looking at one wheel cable I see a difference in the makeup of the wire. One wire looks to be a solid copper type and the other one which I take to be the return wire has a fiber like material instead of a copper core. Anyways, The two back cables (one for right rear wheel, one for left rear wheel) join together on one female side of a connector. The other side of this connector is of course male and then runs them up to the front of the car. This connector has 4 pins in it. Two for each wheel in the back end.

Im thinking that I will have to replace the whole back wiring. I can only assume that GM sells the back wiring harness as one piece. I also cannot seem to find it available anywere yet. I will keep looking today.

My other thought as to why I now get a “erratic signal” error on the scanner is perhaps I have the two wires from the right rear wheel sensor accidently switched around?

This would make a great video for Eric Eh?

coffee

[Joseph]

I GOT IT! Fixed my issue. 🙂

Apparently my solder job was good it just took a little driving to reset the ABS system. I got in the car this morning and fired it up and drove about 8 miles to return a part. ABS didnt come on at all and everything is now fine. Thanks for the replies to my questions.

banana:

[Austin]

great job! not a problem!

[John Hugon]

Sorry I didn’t see this before, I never did this, because I always had a scan tool, but to turn off an ABS light on a GM car quickly:
1. Turn ignition switch to the on position.
2. Using a suitable jumper wire, ground Assembly Line Diagnostic Link (DLC) terminal “H” to “A” for two seconds.
3. Remove jumper wire for one second.
4. Repeat grounding for two seconds.
If you look at the diagnostic connector under the dash carefully it will be lettered so you can see which is H and which is A. Or you can just drive the car and if your ABS system is functioning to specs the light will reset.

I guess you put heat shrink tubing over your repairs?

[Joseph]

[quote=”JTF” post=104473]Sorry I didn’t see this before, I never did this, because I always had a scan tool, but to turn off an ABS light on a GM car quickly:
1. Turn ignition switch to the on position.
2. Using a suitable jumper wire, ground Assembly Line Diagnostic Link (DLC) terminal “H” to “A” for two seconds.
3. Remove jumper wire for one second.
4. Repeat grounding for two seconds.
If you look at the diagnostic connector under the dash carefully it will be lettered so you can see which is H and which is A. Or you can just drive the car and if your ABS system is functioning to specs the light will reset.

I guess you put heat shrink tubing over your repairs?[/quote]

Thank you for the information. Yes, I did use shrink tubing on the repair. The only frustrating part of the whole repair is the lack of information or the difficulty in finding information on my lucerne. Since they only made these cars for a few years I think its just going to get worse. I did buy the service guide online for about 15 bucks. This brings up a interesting note though: We are so lucky to grow up in this age of computers. Alot of information is on the internet. When I was young you went to the library or you had to write the company for information – which took forever. Today ‘youtube’ is a great help and almost anything can be found on the internet. People are so lucky today as compared to years past. 🙂

coffee

[John Hugon]

Don’t worry about the parts or info being hard to find on your car. It’s a “W” body GM vehicle and it shares parts with all “W” body GM cars…..Those cars are like ice cream on the 4th of July…

Yes the internet is very helpful compared to the way we had to get info yesteryear. What’s really remarkable is the info you got on this site to repair your car. Try going to a Buick dealer and ask for that info. 😆

[EricTheCarGuy]

Glad you got it solved. I was thinking an issue with your repair job. ABS wires are shielded, which is the copper fiber you saw. They do this to prevent RF interference from messing with the ABS. Since you were able to reset it and the light hasn’t come back on, you’re probably OK. If it comes back however you might need to replace those damaged wires.

Thanks for the updates. Good luck and keep us posted if things change.

[Joseph]

[quote=”EricTheCarGuy” post=104556]Glad you got it solved. I was thinking an issue with your repair job. ABS wires are shielded, which is the copper fiber you saw. They do this to prevent RF interference from messing with the ABS. Since you were able to reset it and the light hasn’t come back on, you’re probably OK. If it comes back however you might need to replace those damaged wires.

Thanks for the updates. Good luck and keep us posted if things change.[/quote]

That was my first thought about either insulation or shielding. But it pretty much looks like a paint brush (for lack of a better term) when you get past the outer sheathing. But I will keep an eye on it.

I bought the car because my Dad swears by Buicks. He would also say that if I bought a foreign car I couldnt park it in his driveway 😆 So, I looked all around my area (South Bend) and had to drive south to Warsaw to find one. At a dealership I talked them down from 18k at the time to 13k. I figured right then that I just bought a real lemon! But it drove ok. Later I found out that they put a 30amp fuse in the fuse box for the gas pump because it kept blowing the recommended 20amp. This basically melted the fusebox and I had to replace that. I also replaced the fuel pump. Then I had to replace the radio. Started to think I bought a Katrina car!

Im to the point now where everything works as it should. I have a muffled ‘thud’ when turning the steering wheel / driving over bumps that is coming from the front end. Thats about it. I will probably start that next week and see what I have to do.

Eric, I could never have done all this work on this vehical (oil changes, brakes, wiring issues, bearings) without your videos and the encouragement they gave me. You have also saved me alot of money too!!

At our house we call my car the “Bismarck” because of all its problems. Well, I still paid alot less than going out and buying it new so its still a bargin. Bought it at 62k miles and have about 93k on it now.

Would love to see a video on ABS discussing the actual module right on thru the wiring and sensor 🙂 Heck, Maybe you will get a buick in your shop sometime (The horror!) 🙂
Thanks,

coffee

[Author]

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