Hey all, I just took my car out to rack up some miles and try to get my last 2 monitors to set for smog.

While I was out, I noticed that the car jerked the steering wheel quite violently during upshifts, becoming more pronounced at higher speeds.

I noticed the same thing yesterday on the way home from $3200-worth of smog repairs while it spent 14 weeks(!) in the shop, but it was at lower speeds and I put it down to uneven tire pressure, which I rectified before starting out on my drive today.

So due to this violent act and the safety concerns it presented, I abandoned the drive and headed home. I have known that the right front wheel bearing was wanting replacement for some time, and I started to suspect that. I've got them on order for delivery tomorrow.

Anyway, I got home and plugged in my scanner just for poops n chuckles, to see if there was any change in the monitors (no such luck). Now I find I have numerous new codes, including C1258 & C1259, which are codes for wheel LF & RF speed comparison.

My question is: could a bad wheel bearing cause those codes and make the ABS module behave erratically due to that? I'm replacing the bearings tomorrow afternoon, suppose I'll find out soon enough...

 

Hi John,
Sounds very odd indeed. Even if your wheel bearings were completely toast, it is hard to see how that would cause the steering wheel to be jerked. If they were so badly shot that they were affecting the rotation of the wheel, they would do it consistently, and the noise would be pretty unpleasant to say the least. I can't see how they could damage the ABS wheel sensors either, and even if by some fluke one of them did, it would be astonishing if both wheels were affected.
You will probably have changed the bearings by now anyway, but I would be surprised if they were the culprit.
I take it the wheel nuts are all secure?
The other area which I am thinking about is the ABS module. An asymmetrical application of the brakes would cause the steering wheel to be jerked, and the ABS system has the wherewithal to apply brake pressure differentially to each wheel, but from what you are saying this only happens on upshifts. Could an electrical fault cause the ABS to make an uncommanded application of an individual wheel brake? I have never heard of anything of the sort, and even as I write, it seems far fetched, but I can't think of what would cause such a violent jerk to the steering as to cause you to abandon a drive. You mention that there were numerous new codes, could you let us know what they are?

 

Hi, thanks for replying.

I have my hub stripped apart, waiting for the seal to come in before I can start reassembly, plain sailing thus far but when I took the hub nut off I didn't even need to use a spanner, it was just finger tight. There was definite play in the bearing adjustment before I took the wheel off, that'll be gone once I'm done.

To the codes: I got P0446 & P0452, unrelated and probably just the gas cap as I had just got done fuelling prior to my interrupted drive. No CEL though.

I got the 2 subject codes C1258 & C1259 related to wheel speed comparison on the fronts wheels. Then I noticed I have a C1095 code.... ABS module? I've had an ABS warning light on for a loooong time, and a local indie shop told me not to worry about it, I just wouldn't have ABS but brakes would behave as non-ABS.

While I have the hub apart, I notice that there appears to be a ground strap connector at the ABS sensor on the hub, and another connector up at the brake line bracket. No ground strap bridging the gap though...

I'm going to continue on and finish the bearings and feed back once I've driven it again. In the meantime, any more info you can give me on that C1095 code will be greatly appreciated.

Thanks,
John

 

Hi John,
Sounds as if there will be some benefit from tackling the wheel bearings then! Was the nut loose enough to allow the hub to move by much? I'm just wondering whether that would be enough to bring the brake disc into contact with the pads, explaining your steering jerking?
The C1095 code, together with the fact that the ABS light is on and you have other ABS related codes would seem to point to your ABS module being the starting point. There are threads on here and elsewhere detailing the dry solder problem which can afflict these units, and in the absence of other factors, would be a good place to start, not least as there is an inexpensive fix available. I'm assuming your trac fail light is on too?

 

The hub nut was loose enough to undo by hand when I took the split-pin out and there was considerable movement from the wheel before I took that off. The bearing wasn't completely destroyed though, which I found surprising.

The Trac Control warning light has never been on, I had concluded that my car isn't equipped with it, given the amount of read-end sliding about I can induce when the rarely-damp San Diego roads get moistened.

To be honest, I don't even recall seeing the ABS warning light on after that first scary incident, and it's not mobile yet, (long saga yesterday with auto-parts store incompetence), waiting until Wednesday now to get replacement hub seals delivered, so I can't finish the wheel bearing and road test it yet.

Hopefully you're right about the wheel bearing fixing the ABS issue, I was following my instincts mostly when I diagnosed that as the problem.

I'll post back the end results later in the week.

I know nothing of ABS module repair/replacement. Where is it located? Does removal require bleeding the brakes after re-installation?

Thanks again for your input.

Cheers mate, John

EDIT: I read up on the ABS module solder repair, going to wait until I've done the bearings then tackle that if I still have issues. I located the ABS module, next question is how to remove it. I see 2 x nuts on the forward side of the pump/module assembly and one tucked down the aft side. Then another that appears to hold the gigantic electrical connector in place... by removing all of those, would I be able to lift it all up and remove the module from the bottom of the ABS pump? The cluster of rigid brake lines makes it look like that could be a pain in the ****... Tips?

 

Hi John,
Sounds like you are making progress. I am puzzled that you don't have the Trac warning light on if you have so many ABS codes, as Trac and ABS are pretty much hand in glove on the X300. Does the Trac warning light come on when you turn the ignition on? If this has been a long term problem, the bulb may simply have failed. In any event, if your ABS module isn't working, you don't have traction control, which would explain the excitement on wet roads!
Turning to the ABS module repair, JTIS envisages the hydraulic module being removed, which does involve bleeding the brakes, but from memory, there is a suggestion that the unit can be removed by "bending" some of the brake pipes while still attached to the hydraulic module. I have not had cause to undertake this job myself, but had researched it in the course of tracking down a Trac/ABS fault on my car a couple of years ago. For what it is worth, bleeding the brakes isn't a problem if the correct sequence is followed, although if you opt to disconnect the hydraulic unit, try not to let it drain.
I look forward to hearing how you get on.

 

I just went and checked again, "TRAC FAIL" light works with the ignition turned on, and I am 100% certain it has never lit in the 6+ years I've owned the car. ABS light also works on key-on, but has never lit until I reach 15mph, don't know what it's going to do nowadays with the current wheel bearing problem.

I did talk to the indie shop where I had my smog repairs done, he agreed that bearing problems could be a possible cause for ABS misbehaving, as I suspected, but the hub seals don't arrive until late tomorrow, so I still won't know for a bit longer.

So in anticipation of fixing the ABS module, I hit the local soon-to-be-closed Radio Shack and now have a soldering iron ready for the possible repair.

Motivation is returning, 2-ton paperweight isn't getting to lie down just yet...

 

Alright lads, I just (yes, just now) finished my second wheel bearing. I haven't test-driven the car yet, cuz it's Friday evening and I have beer in me.

I tested it last weekend after doing the first bearing, little noticeable improvement in front-end behaviour, maybe a little better but it still felt very floaty.

When I tore down the other side hub there was as much or more play than side 1, and the wheel speed sensor was equally choked up with grease and brake dust. Hopefully better now with new bearing and clean sensors.

So, questions:

In order to reset the C1258 & C1259 codes, do I need to clear them from the ECU? Or will they clear by themselves after some miles assuming the speed sensing issues are fixed?

If my ABS module is bad, could I pull the fuse/relay and disable it leaving just brakes to check if the ABS is causing issues?

Help appreciated,

 

The codes should clear while driving. I know people have driven some, but not all, model jags with the abs module removed, so disabling it may work.