Mechanics

ABS AND TRACTION LIGHTS COME ON

2003 Buick Rendezvous • 100,000 miles

Have a 2003 model and have this issue (abs and traction lights come on) now for some time (at the moment on the front left wheel).
Went through changing wheel bearings on both front wheels but this did not solve the problem. Finally for the right wheel garage guy changed the connector on the Front right wheel and this solved the problem for a while. Started again this time with the left wheel, changed the bearing there and worked ok for a few weeks and back again the problem came.
Now I have checked the connector at the left wheel, managed to adjust the harness so there is no pulling on the connector at the bearing when turning and have secured the harness with additional ties. The problem went away but came back within two weeks. Just to make sure it was the same wheel, removed the connector again and reconnected, again initially it works fine but problem returns within 10-12 days. The wire in the harness is fine not broken anywhere so its strange after removing and putting back the connector it works for a few days but problem comes back after that, Also Abs light comes on more frequently as time goes by sometimes the lights come on before even moving out of park at other times when driving on a straight stretch with no apparent cause to mal function.
So it seems after removing and reconnecting the abs sensor the lights go away and it drives Normal but problem comes back after a while.
Could it be moisture getting into the contacts and causing it to malfunction, though you would think after they dry out the problem should go away but does not, unless as I mentioned disconnecting and reconnecting the abs sensor at the wheel.
Would appreciate any help and thanx in advance
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GP27
May 4, 2012.



What you're describing sounds exactly like what we used to run into with tvs. Walking across the floor triggered some problem such as flashing brightness. Removing a module to inspect it, then reinstalling it solved the problem for a few weeks. It was due to a light film of corrosion built up on the contacts and weak tension on the spring-loaded contacts. The scratching action of sliding the module out and back in scratched a temporary clean spot but it wasn't a solid connection.

The fact that you've noticed the warning light turns on before even moving the vehicle proves the problem is not related to the signals generated by the wheel speed sensors. It has to be electrical-related. What you might consider is going right to the plugs on the computer to measure the resistance of each wheel speed sensor. Compare the right to the left side. If one circuit is open, leave the ohm meter connected while you work on the appropriate connector by the wheel to see if that affects the reading. Most terminals have a way to remove them from the connector body so you can bend or squeeze something to make a tighter contact. Lightly sand the male terminals and coat the rubber weather-pack seal with dielectric grease.

I'm sorry that I can't get into any of the online service manuals to tell you which wire colors are for which wheel. You might be able to see the wires at the connectors by the sensors to tell which ones to meter with the ohm meter.


Caradiodoc
May 4, 2012.
Thanx for the quick response, Not sure how to get to the computer terminals.
I have bought a new connector with the harness but am unsure how to replace it, If I could replace it, would atleast eliminate the connector issue.
Would like to replace the entire length of the harness rather than splice the wire close to the connector just to eliminate any weak spots that might be present in the harness itself.
Any diagram that I could use to replace the connector with harness would help


Tiny
GP27
May 4, 2012.
Replacing the sensor half of the connector is difficult because the wire is braided to make it flexible like an extension cord, but you got that part with the new sensor anyhow. If the terminals in the vehicle half of the connector are suspect, the dealer has repair kits with just the terminals for every connector on their vehicles. That way you don't have to buy the whole connector or harness.

If you already have the connector, splicing the wires isn't hard but it does take a little time to do a good job. Cut the wires beyond any splash shields to put the splices in a protected area. That will help insure the quality of the repair. Slide about two inches of heat-shrink tubing onto each wire. To splice the ends, don't twist them together like you are going to put a wire nut on them. Instead, hold the bare ends side-by-side, (one wire going each way, not parallel to each other), then twist them around each other to hold them together. Solder 'em, then slide the heat-shrink tubing over the splices and warm it up. If that explanation is as difficult to understand as I think it is, I'd consider adding a page with pictures to my web site.

You can get heat-shrink tubing now with hot-melt glue inside that will seal the splices really well. I first ran into that at the Chrysler dealership I worked at in the '90s, but you can find it now at any auto parts store for lower cost than at the dealerships.

To replace just the terminals you usually need the special crimping pliers. Without that, I've soldered new terminals to the wires before but in some cases the terminals won't fit into the slots if they aren't properly crimped. If you're a regular customer at the dealership, they might borrow you their crimping pliers. Many auto parts stores borrow or rent tools too. If they sell the special terminals, (not just the generic crimp-on terminals), they might have the correct crimping pliers too.


Caradiodoc
May 4, 2012.
Thanx caradiodoc, replaced the connector with harness over the weekend, so far so good, will wait and see. The one thing I noticed this time was the position of the connector on the bracket at the wheel hub, when the wheels are turned fully to the right the connector touches the steering Rod end so what I did was positioned it an angle downward and secured it with a tie. Only problem in this position it touches the chassis when wheels are turned fully to the left. I adjusted so the touching is minimal lets see how it holds up. Any ideas are most welcome, thanx


Tiny
GP27
May 7, 2012.
No more turning right from now on!

It's good that you identified something related to the connector problem. If that is the way it was designed, the problem is likely occurring on a lot of this model so there could be a service bulletin on it. Sometimes an improved part is developed. Sometimes there is a patch repair such as your tie strap idea. Normally the connectors are behind a splash shield or to the inside of the inner fender. Besides getting the connector in a dry place, the idea is to have all the flexing done in the soft, flexible wires on the sensor. The wires on the vehicle side of the connector can't tolerate much flexing before they will break.

It doesn't hurt if the connector touches anything, but from what you described, it sounds like there's a lot of flexing going on that's putting twisting pressure on the connector.


Caradiodoc
May 7, 2012.
I stand corrected, ... Again. I looked at a photo of your wheel bearing and saw the wires for the ABS sensor are really short. Here's a picture from rockauto. Com of the harness you must have replaced. That cable is designed to be flexible. The hint, if you look at the red arrow, are the little squiggles in the wires. It's common for finely braided wires meant for flexing to do that.

You see there's a clip on the wheel bearing half of that connector to attach it to a bracket. The best I can suggest is to be sure that clip is mounted securely so the most flexing is done near the center 80 percent of the cable and as little as possible right next to the connector. You might even look into forming some silicone gasket sealer around the wires next to the connector to stiffen that area up a little. Flexing shouldn't hurt the main part of the wires but they will have a greater tendency to break right at the terminals. Reducing the tendency to flex there might make the entire harness last longer.


Caradiodoc
May 7, 2012.