If I plug in a working abs sensor, will the light go out?

[len_beach]

I have an abs light on which has been diagnosed as an open circuit on the drivers side rear.

Ive taken a punt on a used stub axle and abs sensor for £30 rather than a new Renault sensor for £125. If I simply plug the new sensor in without fitting the stub axle, will the light extinguish or does the senso have to take a reading from the abs ring?

 

[Jaff.]

Normally have to move the car a few meters before it registers

 

[Sam@NP]

Are you sure that's what the known fault is?

 

[len_beach]

It was diagnosed on clip by Doncaster Diagnostic Centre as an open circuit Sam. I could be a broken wire but I thought changing the sensor would be a quick option as I am fitting camber shims anyway.

 

[Owen92]

An open circuit is what it says it is, a break somewhere in the circuit so you are taking a 50/50 chance on it being the sensor.

 

[DaveDreads]

I had a knackered ABS sensor years ago that originally caused my SERV/ABS/TC lights,
it was replaced but i've had the damn thing reappear every now and again ever since,
no amount of diagnostic checks can find the problem, there are no fault codes on mine at all.

But yet it remains and will randomly show up now and again untill the engine's turned off,
then months can go by and I wont see it, then it'll show up to say hello again.

 

[len_beach]

An open circuit is what it says it is, a break somewhere in the circuit so you are taking a 50/50 chance on it being the sensor.

I appreciate that but it could be break in the cable running over the rear beam and I thought as I'm fitting the shims I may as well swap it.

 

[Owen92]

You should actually diagnose the fault rather than just chucking parts at it though mate. If you've got a multimeter disconnect the sensor and run a magnet backwards and forwards across the sensor, if you get a fluctuation the sensor is more than likely good.

 

[len_beach]

You should actually diagnose the fault rather than just chucking parts at it though mate. If you've got a multimeter disconnect the sensor and run a magnet backwards and forwards across the sensor, if you get a fluctuation the sensor is more than likely good.

I know it's not the ideal solution. The problem with the rear abs sensor is you have to remove stub axle to get the sensor off.

I have a multimeter and may be able to squeeze a magnet in above the abs ring. Will any size magne work even if it's really thin?

 

[Owen92]

The bigger the magnet the better. You could also just spin the wheel but bear in mind that if you don't get any fluctuation it could be the pole wheel rather than the sensor (unlikely due to open circuit)

 

[len_beach]

The bigger the magnet the better. You could also just spin the wheel but bear in mind that if you don't get any fluctuation it could be the pole wheel rather than the sensor (unlikely due to open circuit)

Thanks Owen. I'll test the process on the replacement sensor and see how the sensor fitted reacts.

So I'm just testing for a current? I'm pants with electrics.

 

[Owen92]

I believe you are actually testing for voltage (I'm not over ally great with electrics so trying to remember what we were told at college) but you could always try both.

 

[len_beach]

I believe you are actually testing for voltage (I'm not over ally great with electrics so trying to remember what we were told at college) but you could always try both.

Magic. I'll give it a whirl. Thanks Owen.

 

[Owen92]

You're welcome mate. Let us know how you get on?

 

[len_beach]

Right, I tested the o/s abs sensor today along with the n/s and the replacement sensor.

I used a multimeter and a small magnet waved across.

The suspected dicky sensor showed a reading of 0.3 to 0.4 (I can't remember what setting I had the multi-meter on).

The suspected working sensor showed 3.4-3.5.

The assumed working replacement showed up to 4.9 howeve I could get the magnet much closer to the reading face with this.

Now I'm guessing this means the sensor is the issue?

 

[Owen92]

That would say its a sensor fault to me. It looks like you had that on volts which in general (don't know specs for Renault) would be in tolerance for the the good sensor.

 

[len_beach]

That would say its a sensor fault to me. It looks like you had that on volts which in general (don't know specs for Renault) would be in tolerance for the the good sensor.

It was volts Owen. I tested on the replacement sensor to see which setting gave a reading then went from there.

The assumed working sensor was tested twice and was consistent. The suspected faulty sensor was tested in various positions etc around 8 times and all readings were low.

Im guessing the low voltage is what's causing the issue as its not high enough to register as working?

 

[Owen92]

Yeah a low voltage like that would be out of the expected operating range more than likely causing your ABS fault. 99% certain changing the sensor should cure the fault

 

[len_beach]

Fixed. It was a dicky abs sensor. Thanks for your help Guys.

 

[Owen92]

Good to hear that mate.