Dealer put bearing in backwards, maybe. Should I check first?

2007 Prius, my daughter's car. Dealer just replaced the front left wheel bearing. After driving the car back and forth to work (local roads only) for the week, as she drove to visit us the ABS, VSC and " ! " lights came on after some highway miles.

Took it to AutoZone where the OBD2 reader said it was a problem with, yes, the left front ABS sensing system, where the bearing had just been replaced. The guy at the counter immediately said the dealer probably put the bearing in backwards so the magnetic strip was on the wrong side. Called our own local mechanic (Saturday morning so they couldn't see car then) who advised to take it back to the dealer, he didn't seem to think my taking the car to him so he could check the bearing was a good idea, I understand that his taking enough stuff off just to check the bearing might be a lot of labor which I couldn't recooup, so I guess he figures that the best case scenario is that the dealer checks, finds it's backwards, replaces it no charge. (I realize that alternatively ABS sensor or harness could be damaged, but if so it almost certainly was damaged during this repair.)

Which leads to: is the 2007 Prius bearing indeed the kind that has that metal strip on one side, so it even can be put in backwards?

If it is, and assuming the bearing was put on backwards, my natural pessimism tells me that a dealer would have a strong incentive both not to admit it (for fear of a review that said they put it on backwards) and also not to absorb the cost of putting a new one in. It is very hard for me to picture a dealer saying yup, it was backwards we fixed it, no extra charge. An unscrupulous one could do this, and I don't think it's too far fetched: pull everything off and, if they see the bearing was in backwards, replace it without telling us, and then replace the ABS sensor saying that was the problem. They could then tell us the bearing was installed correctly but the problem was the sensor which they replaced, then they could charge us labor for checking a bearing that (they say) turned out to be fine, admit no mistake, and also charge us for installing an ABS sensor (that perhaps we didn't need). Problem fixed, no admission of fault, and lots of extra charge. They would know the light wouldn't come on again because the real problem, the bearing, is fixed. So in the end we'd have paid essentially about twice what a correct bearing installment should cost. Might sound far fetched, but if you think about it a while not really, given the economic pressures, etc. We'd have no way of knowing whether or not they did all this, the only way to tell would be to watch the whole process of checking it and I assume no dealer would let you do that.

Ideally it would be great to independently verify whether or not the bearing was in backwards before taking it to the dealer. But I assume that itself would be a big labor charge at our local place that we couldn't recoup. Despite the time and effort, I'm wondering if it would be worth it for me to check it myself - if I did find it was in backwards we'd have a rock solid case for the dealer replacing the bearing free of charge. If it wasn't in backwards, so much the better, we'd save the risk of the dealer charging us for more labor to check it, and it's probably the ABS sensor.

Any advice as to how to deal with this situation would be welcome, in order for us not to be totally at the mercy of the dealer.

Additional questions:

1) Assuming the bearing is that kind with the metal disk on one side, how much stuff would I have to remove before I could access the ring in such a way as to see if it magnetically attracts a screwdriver or whatever? Could I do that short of removing the hub? Would I have to remove the ball joint and axle? Are there seals or a snap-ring that we'd have to take out to access the magnetic strip?

2) I watched this pretty long but thorough video on replacing the bearing on a 2007 Prius:

In the video it looked to me that on a 2007 Prius the hub might not be pressed into the knuckle like on many cars, but is just held on by 4 bolts? Could that be true? If so, it seems like if I had to take the hub off to examine the bearing it would be a lot easier than if it were pressed. (But also I might have to take the whole knuckle off like he does in the video to access the bolts? Not sure. Still a lot easier than pulling a pressed hub?)

I have never done this before, but I am retired and have time and would be willing to risk the usual frustration and frozen bolts and it's taking eight times more time than I thought and hopefully not breaking something else in the process, (We could loan our daughter one of our cars.) if it's reasonable to check the bearing myself. Plus it seems to me since the bearing was just replaced none of the connectors, ball joint, etc., should be frozen, they should come off pretty cooperatively. If it's not in backwards, but then I know for sure, and learned stuff. I could even try to replace the bearing if it is in backwards (I'd try to double check that with a mechanic if I took the whole knuckle off or hub off), document that it was backwards with pictures, and then ask for a refund - except that it seems to me a refund would be far less likely than a free correct installment if I could document it was in backwards. A lot of extra work, but with some certainty and less of a feeling of helplessness, as a result.

A last thing that occurs to me is, if I could test the ABS sensor without too much labor before doing anything else, if it's good (or if it's bad and I replace it but the ABS lights stay on) I could tell the dealer I know it's not the sensor, must be the bearing.

What would you do?

Thanks for reading this long post!

 

So, update: I’ve been looking into types of ABS sensing systems. It looks like for different cars the part that rotates and is sensed by the sensor can either be a toothed metal ring, which can be in the driveshaft or on (or in) the bearing itself, or can be that circular magnetic strip that is on only one side of some bearings. I found a photo of a driveshaft, allegedly for a 2007 Prius. You can see a toothed ring between the CV joint boot and the splined spindle. If that is the ring for the ABS sensor, and all 2007 Prius’ have that, it seems to me that we can eliminate the dealer’s putting on the bearing backwards, since the sensor ring is not even on the bearing, so putting the bearing in backwards would make no difference to the ABS.

Anybody know if that’s the case, that the backwards bearing possibility might not apply to this car?

P.S. How can I attach a photo to a post directly from my photo library in my phone? I clicked on the photo icon but it asked for a URL. Thanks, new to this site.