Hiiiii, Abs sensors say they are on the wrong wheel!!!

[Ellneortic]

Hi Guyyyys.
So I got me a Citroen Dispatch, 07. Yesterday. Short Mot so I gota get my finger out and fix a few things.
The ABS light is on. I connected up Launch pro diagnostic jobber and it said Rear right hand wheel speed sensor
signal open circuit or short to earth or short to battery.
So I jacked up the said rear right wheel spun it and looked at the scanner. Nothing at all. no readings.
I then spun the passenger rear... it showed up as front l/h 3 kmh
I then spun the front passenger... it showed up as rear r/h 3 kmh
I then spun the front drivers... it showed up as rear r/h 3 kmh.

I've never had anything to do with ABS before but I'm wondering if it's possible someone could have connected them all
up the wrong way at the ABS computer ??

I took out the one not working to clean it but its just a plastic blob with no copper bit on the back. I cleaned it but it was
immaculate and put it back. no difference.
Any pointers, help, direction would be great please guys.
Cheeeeeers. Mark

[GiveMeABreak]

I don't see what the problem is - rear right would be correct from the driver's position point of view as you have described???

[Paul-R]

It sounds as though the front wheels have been put on the rear and vice-versa. From your description it sounds as though there are four separate sensors (one for each wheel - not all cars do have this) and the rear R/H - or possibly the front RH - sensor is broken. Others will know for sure if there are four sensors.

Swapping the wheels back to what they were before will sort out which sensor by seeing whether the error messages change or not.

[Ellneortic]

I don't see what the problem is - rear right would be correct from the driver's position point of view as you have described???

Cheers, I,m wondering why the diagnostic says rear right fault and it clearly is the rear right faulty But... When I spin the wheels The front passenger wheel shows up on the scanner live data as the rear right wheel moving?? Why do the wheels i spin show up as different wheels on the scanner. Strange just wondered if they could have been connected wrong. Just wondered if it ment anything else like when this happens it also means the rear indicator bulb will burn out on a sunday, Ill get stopped and fined for not having a spare bulb or something obscure. I probably didn't explain what I was meaning very well. Thanks for your help.

[Ellneortic]

It sounds as though the front wheels have been put on the rear and vice-versa. From your description it sounds as though there are four separate sensors (one for each wheel - not all cars do have this) and the rear R/H - or possibly the front RH - sensor is broken. Others will know for sure if there are four sensors.

Swapping the wheels back to what they were before will sort out which sensor by seeing whether the error messages change or not.

Thanks very mucho. Ill try that with the wheels tomorow. cheeers.

[Paul-R]

If the message changes position then there's a single sensor and it's probably the sender in the tyre valve that's at fault. If it doesn't change then there are individual sensors and the rear one, or its connection, is faulty in some manner.

[xantia_v6]

Don't ignore the possibility that the code reader has the sensor positions swapped.

[Paul-R]

I could imagine left to right being swapped but not front to rear. Still it's a possibility I suppose.

Is there no-one around yet who knows for sure where and how many sensors there are?

[GiveMeABreak]

@Ellneortic if you can provide your VIN, we can provide you with the sensor parts and type.

[wheeler]

It sounds as though the front wheels have been put on the rear and vice-versa. From your description it sounds as though there are four separate sensors (one for each wheel - not all cars do have this) and the rear R/H - or possibly the front RH - sensor is broken. Others will know for sure if there are four sensors.

Swapping the wheels back to what they were before will sort out which sensor by seeing whether the error messages change or not.

Are you confusing ABS systems with TPMS ?? Every ABS system has to have a speed sensor on each wheel otherwise it wouldn't work. swapping wheels around wont do anything either as the sensors are in the hubs.
As for the mis reading, I wouldn't worry about it, it may just be a software glitch with your diagnostic device, you even get things like this with Lexia (Citroens diagnostic device). a good few years back there was a version of lexia that read the up & downstream oxygen sensors round the wrong way on certain ECU's

[Paul-R]

Whooooops wheeler, you're quite correct. Forget everything I wrote! The ABS sensor is fixed to the suspension at each corner. The OP needs to find the RH rear and RH front sensors are and, at first, disconnect each one electrically to see which is really at fault (the error will double up on the one that ISN'T at fault). Then look closely at the wiring, connector and then the sensor itself.

[Ellneortic]

Big thanks you guys for the reply's and info. I'll have a good look at it tomo and see whats going on. I did have a look for it today but didn't see where the sensor wires go to under the bonnet. I thought they would all go to the place where all the brake lines go to but it doesn't look like it.
Ill report back tomo on any findings. Cheers Guys.

[Ellneortic]

H
i Guys, I've looked at the sensors but I cant see where the wires from them go to? I thought they would go to the ABS pump but there are only 6 brake pipes connected there. anyone know ? the wires start off looking like break pipes but are obviously not and then get lost behind the fuel tank I'm wondering if they go to the BSI unit ? bsi is that right the one under the bonnet with all the relays and fuses?
Peugeot Expert. I'm not feeling very confident at the mo, hopefully I can get somewhere with it tomorrow. It was all going ok till the decided we would have a new kitchen and a freezer that wouldn't fit. Thats all done now so I need to get cracking on the van before she finds another job to dooooooo.

+

[Ellneortic]

Me again, it's ok guys I found it the big block connector on the side. Think I need my eyes examined lol. Just need a diagram of what pins are what,, thanks guys.

[GiveMeABreak]

Can you PM your VIN and I'll have a look in the next hour for you.