ABS Help

This is for our '05 Toyota Camry with 125K miles on the ODO, has ABS but no TPMS.

Around a few weeks ago the ABS light started flashing on start-up. Turned engine off and it went away. This has happened 3 times to far. The light stays off otherwise. Before this we had new tires installed and the car aligned and they said the rear was a bit off (had uneven tire wear), not sure if related or not.

I was able to read the code with shorting two pins and I get 33 & 34 which is both the rear wheel sensors. The part that I am suspicious about is both sensors going out together that not make sense. So I am thinking it is the wiring somewhere. Hopefully not the module ($$, we would probably go without ABS in that case since we are in Southern CA).

For now I have cleared the codes and want to see if they return. The sensors are expensive and seems like I have to take the rear bearing off to change them, so not keen on just throwing parts at it.

Any thoughts on how to approach the troubleshooting?

Galant, you have the same setup I do. I believe the sensor is located in the back of the hub & bearing assembly. I believe the sensors can be accessed and removed from the back of the hub & bearing assembly without removing the whole assembly. It’s a plug and two bolts.

Ask the dealer’s parts guy for an “exploded view” drawing of the rear hub & bearing assembly showing the wheel speed sensors.

NOTE: I’m relying on my memory on this, so I could be wrong, but I think you’ll find I’m correct.

Re: the troubleshooting, you have an OBD!! system. Chassis © codes might give you the clue you need, but if there are none because you’ve clear them you may have to wait for the CEL to return… if it does.

Try getting under the back and clean the sensors with a garden hose. You may have dirt in them, cleaning them is easy and may solve the problem. Since both are tripping a code it may be wiring and not dirt, but being in Southern CA it is not to cold to try the hose.

Those are more than likely false codes in history from your smog check. What city are you in? If you are close to Downey I can pull the codes with a scanner for you.

@the same mountainbike
I have rear drum brakes, I am looking at the sensor part picture and do not see any bolts. I also have read the codes already with shorting pins 4 & 13 on the OBDII connector. I am not sure if a code reader will give me more info.

Thanks for the generous offer. I am in Santa Clarita, so you never know. My last smog was 2 years ago. I have code 33 & 34 based on the flashing ABS light by the above (poor-man’s) method.

If you can remove the sensors, do so and see if they are dirty or corroded. If so clean them and try to inspect the hub area they looked at. That might need cleaning too.

Unless you’re in Canada, your r ear brakes should be discs with drums in the center for the parking brake shoes. I’ve attached a link wherein you should be able to see how they’re built.

@the same mountainbike;

I’m not in Canada and have the plain drums in the back (My Mazda has the setup you mention and well familiar with it). My Camry is special, no side airbags and rear drums, don’t ask me why.

I am waiting for the code to repeat itself, but again can;t believe both rear sensors going bad together. I look at the sensor part pic online and seems like it snaps in and there are no bolts. This would be the perfect thing for me to break.

As odd as this may sound, it may actually be your front speed sensors/wiring. The diagnostic codes are generated by comparing speed sensor signals. If one is missing a signal while the others have a signal, the code would go active for the missing signal. If there is electrical noise getting coupled into the front speed sensors, such as a loose ground, the ECM might being seeing front speed sensor signals and not rears and create diagnostics on the rear. I would check wiring on the front sensors also before replacing both rear sensors. I have had to replace sensors and they have failed within a month of each other but not at the same time.

Interesting. I stand corrected.
In that case, I’m “in the dark” on this one.
I’m thinkin’ an exploded view drawing from the dealer’s parts guy might be the next best option to locate the sensors.

code 33 and 34 are 100% for the rear sensors

I know this because I looked in my 2005 Camry factory service manual

And no, it’s not easy to replace these sensors. Apparently a puller is required to remove them, and a press is required to install them


For what it’s worth, the sensors are supposed to have 1.3 to 1.6 kiloohms resistance at 20 degrees celsius

At least you could check if they’re within spec

You could also use the ac voltage function of your multimeter to check if they produce at least 500 millivolts, for example, when you spin the tire as quick as you can


Thanks for the info. I actually crawled under the car and see the wires going right to the rear of the hub and does seem like a difficult R&R. Might be easier to buy a wheel bearing with the sensor on it.

So far, one day and no flashing ABS lights.

I will try and get the wheels off and see if I can get the measurements. Between my work and my wife’s and everything else going on, it is difficult to find the time.