ABS light on (without parking brake light)

[WildChild]

ABS light just came ON on my 2007 Yaris. What are the most probable cause for this light to look at before having the car scanned?

I plan to take a look at the two front ABS sensors that may have been removed/placed back on both sides for a CV axle and an axle seal replacements...

I had the ABS+parking brake (!) light combo last winter that went away after cleaning/greasing the contacts on both rear wheels, could it be related even if I don't have the parking brake light lit this time?

Thank you!

[CTScott]

There are a ton of threads about this issue. The most likely cause is corroded contacts on the rear sensors.

[WildChild]

There are a ton of threads about this issue. The most likely cause is corroded contacts on the rear sensors.

Yes, I know about this one, but it lit both the ABS and Park (!) lights. This time only the ABS light is lit. Could it be related?

[CTScott]

In theory only the ABS light needs to come on for a bad sensor:

"When a failure occurs in the ABS system, the ABS
warning light comes on and its operation is
prohibited. In addition to this, when a failure which
disables the EBD (Electronic Brake force Distribution) operation occurs, the brake
warning light comes on and its operation is
prohibited."

[WildChild]

In theory only the ABS light needs to come on for a bad sensor:

"When a failure occurs in the ABS system, the ABS
warning light comes on and its operation is
prohibited. In addition to this, when a failure which
disables the EBD (Electronic Brake force Distribution) operation occurs, the brake
warning light comes on and its operation is
prohibited."

I tried to jump the CG and TC pins on the OBD II port and I'm getting all the following codes with ABS light flashes:
33
34
35
38
39

Do you have the information about what they mean?

[CTScott]

33: Right rear sensor
34: Left rear sensor
35: Foreign Object is Attached on Tip
of Front Speed Sensor RH
38: Foreign Object is Attached on Tip
of Rear Speed Sensor RH
39: Foreign Object is Attached on Tip
of Rear Speed Sensor LH

[WildChild]

33: Right rear sensor
34: Left rear sensor
35: Foreign Object is Attached on Tip
of Front Speed Sensor RH
38: Foreign Object is Attached on Tip
of Rear Speed Sensor RH
39: Foreign Object is Attached on Tip
of Rear Speed Sensor LH

Allright, I reset the codes by pressing 8 times+ the brake pedal, drove a few KM and only 35 came back. It might in the end be related to this axle seal replacement on passenger side. Will take a look at it tomorrow.

[WildChild]

I just removed the sensor to take a look at it. The sensor itself was covered with drips of rust. Looking inside the hole, there was also a lot of rust. Could it be a cause for "foreign material on sensor"? Is this sensor supposed to be completely sealed to protect the inside? I'm not sure if I saw rust in there when I removed the sensor on the other side a few weeks ago.

After cleaning the sensor and putting it back, clearing the code, the ABS light came back within 100 meters, again with a 35 code.

I will check the sensor for continuity later tonight or tomorrow. If the sensor itself looks good and there isn't supposed to be rust there, what parts could need replacement?

Thank you!

[CTScott]

I just removed the sensor to take a look at it. The sensor itself was covered with drips of rust. Looking inside the hole, there was also a lot of rust. Could it be a cause for "foreign material on sensor"? Is this sensor supposed to be completely sealed to protect the inside? I'm not sure if I saw rust in there when I removed the sensor on the other side a few weeks ago.

After cleaning the sensor and putting it back, clearing the code, the ABS light came back within 100 meters, again with a 35 code.

I will check the sensor for continuity later tonight or tomorrow. If the sensor itself looks good and there isn't supposed to be rust there, what parts could need replacement?

Thank you!


The 35 could be due to foreign matter on the tip of the sensor or on the ring that the sensor reads. The rust visible through the hole could mean that the ring is coated.

The ring, by the way, is part of the end of the front axle.

[WildChild]

The 35 could be due to foreign matter on the tip of the sensor or on the ring that the sensor reads. The rust visible through the hole could mean that the ring is coated.

The ring, by the way, is part of the end of the front axle.

By front axle, do you mean the end of the CV axle/driveshaft, or the hub?

[CTScott]

By front axle, do you mean the end of the CV axle/driveshaft, or the hub?

Yes - The end of the CV axle/driveshaft, just before where the spline enters the hub.

[WildChild]

The problem is finally fixed. There was so much rust on top of the sensor hole and within the hole that I'm pretty sure that the sensor shifted. It was impossible to put it back in place correctly.

I sanded all the rust on top of and in the hole, removed a few rust flakes near where the sensor tip gets, put some grease on top of the hole and on the base of the sensor to avoid water getting in and I put it back completely in. After clearing the code and driving many KMs, the light didn't come back.

[thetut]

Watch this: https://www.youtube.com/watch?v=PD1V6pv2ej0