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My Nissan X-trail T30 ABS actuator make noise and pulsation in brake pedal while braking gently under 30-40km/h speed. No fault code, no ABS or engine light.

If i take out the ABS fuse, no noise and brake work fine.

Question are

1- If a ABS sensor is defect or dirty, should it give a fault code or fault light?

2- is there any way to test each ABS wheel sensor from car hood area to find out which one is defected Or i must go through each wheel sensor on wheel area?

3- There was an old fault code C1114 which my local mechanic has deleted 4 weeks ago but now it show me no fault at all, although it has same ABS Noise.

What it can be? Any idea??

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The fact that there is no fault codes or ABS light it probably means that there is either a mechanical fault with one of the wheel speed sensors or a intermittent short circuit.

I've seen many things before that cause this: 1. Worn/Rusted exciter ring, usually either on the hub or the driveshaft it will be magnetic or a toothed ring. It could be corroded or damaged.

  1. Where the wiring leaves the vehicle to attach to the sensor it is very vulnerable to being rubbed by the wheel or suspension components. This exposes the copper and leads to an intermittent short circuit giving the ABS the impression that wheel has locked up.

  2. Incorrect gap between sensor and ring. Usually this can't be adjusted so something would have to be damaged.

  3. A wheel bearing could be so badly worn that the sensor sometimes has no reading

  4. Rare but it could be a fault ABS ecu

How to check:

  • Visually check all the wiring where it leaves the vehicle body across the suspension to the wheel sensor.

  • Visually check the hub and sensor for obvious damage and spin the wheels by hand to check for play in the bearings.

  • With use of a scan tool with live data and have an assistant monitor the wheel speeds when there car is being driven, the faulty wheel in question will either show a dramatic drop or increase in speed compared to the rest.

  • Have a someone hook up an oscilloscope to each sensor in turn and monitor the graph will the hub is being spun and while someone if wiggling the wiring. You can then usually eliminate either wiring or the sensor etc

protected by Community Jul 29 '18 at 11:34

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