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ABS/ Traction Control lights

243 Views 6 Replies 3 Participants Last post by  repairman54
A while back my ABS and traction control lights came on. The code that was thrown was for the passenger wheel speed sensor, so I changed it and used a scanner to clear the code. Within 200ft both lights came back on.

Now every once in awhile especially when it's been raining the lights will go off for awhile. When they decide to come back on I can feel the ABS in the peddle. Sometimes the whole car will bog down and not accelerate.

I don't know where to look next whether it's the harness, connectors, wheel bearing, or abs control module. Where should I look next?
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Need to rescan and see exactly which codes are being reported. Could be a bad sensor even if new or aftermarket or the tone wheel that the sensor reads is defective.
The code that is coming up is

C0040-18
Right Front Wheel Speed Sensor - Low Signal Amplitude

Also after clearing the code, the lights come back on at around 9-10 mph

I already changed the sensor once.
From a shop manual, causes for your code are,
  • Physical damage
  • Debris on the wheel speed sensor or the encoder ring
  • Loose or worn wheel bearing
  • Loose or improperly mounted sensor
  • Air gap between the wheel speed sensor and the encoder ring too large
  • Water intrusion in the wiring harness
From a shop manual, causes for your code are,
  • Physical damage
  • Debris on the wheel speed sensor or the encoder ring
  • Loose or worn wheel bearing
  • Loose or improperly mounted sensor
  • Air gap between the wheel speed sensor and the encoder ring too large
  • Water intrusion in the wiring harness
What exactly is the encode ring and where is it?

I would believe water intrusion because of the symptoms I have when it rains.

Also, a couple days after I changed the sensor I took it out to inspect it. I was covered in what looked like rust colored dust. Is this normal?
What exactly is the encode ring and where is it?

I would believe water intrusion because of the symptoms I have when it rains.

Also, a couple days after I changed the sensor I took it out to inspect it. I was covered in what looked like rust colored dust. Is this normal?
Encoder Ring is on the back of the Hub. You can lay on the ground (with a flashlight) and look at the backside and see it. There may be a section missing. This is what happened to mine (over a year ago ... and it's still on the vehicle).

The "dust" is probably brake dust?
Rust dust may be from the hub bearing.
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