Citroen XM Forum

Just did ours last night.

I also replaced the end silencer since I noticed mine was getting quite rusty. It didn't leak, yet
The one I used as replacement is from a TCT....it fits and it sounds just the same. The rear end isn't visible underneath the bumper though.
It'll give me some more time to save up for a stainless steal......that is to say if I can the ABS sorted.

So I put my spare front bendix sensor in the left rear axle. No success, even after halfway replacing the wire going to the sensor previously
Front sensors have to be made to fit by the way because of the heat shield but it is no problem really to do so.

I'll now have one more option of course namely making a new wire going through the engine bay to the ABS ecu. Might struggle to find the right wires

sodding ABS, even more annoying as you know what is at fault... Just can't get to it. Wonder if you could develop wifi ABS that would sort out the wire issue.

Anyway, happy days on the exhaust!

That is annoying on the ABS Jaap

It should be possible, I'd have thought, to substitute a suitably valued resistor for the sensor in order to just confirm the wiring is OK.

John (xmexclusive) should be able to advise the correct value of resistor to use...

And also advise if there might be further connectors in the loom that mat be the cause..

I wish you greet ABS Success

The value of resistor to use is 1.2k Ohms.
This is mid value on the Bendix sensor lower resistance range.
Most Bendix sensors (those made since 1992) are higher resistance range (mid point 2.7k Ohms).
Second generation Bendix ABS ECU's see both ranges but not the gap in between.
First generation Bendix ECU's only see the low range so only work with the cars original sensors and not the replacements.
Fix for this anomaly is to replace and scrap any first generation Bendix ABS ECU's.
Will add the marked part numbers some time.
Do not use 1.0k resistors as the test resistor as this is also the ECU lower limit.
Tolerance on resistor value means typically half of them will be below 1.0k so the ECU sees them as faulty.

There are no connections in the ABS wiring between the ECU plug and the Wheel sensor plug.
The wires are Twisted pair coloured green and brown.
The length of the wires are easily tested using a known good sensor or test resistor.
First test the sensor and note its resistance value.
Then plug it in and measure using the contacts at the ECU plug.
LHF wires 18 & 36, RHR wires 17 & 35, RHF wires 16 & 34 and RHR wires 15 & 33.
The resistance measured this way should still be close to the measured sensor value.
My test resistor with Bendix plug is currently in Ireland on loan to Robert to help sort out another ABS fault.
I am happy for it to be sent on once Robert has finished with it.

Most of this has previously been relayed by PM.

Japp advised me that he had found the wiring to the rear sensor to be yellow wires.
I heard no more after I advised him that the only yellow wiring to the rear axle was the electrovalve wiring.
I suggested the wiring needed more detailed investigation.

John

That is so right John, I never touched the ABS after your last PM because I lost the plot a bit with the ABS and I followed but only up to yourl your last PM. I got tired of being underneath that car. I thought that my wiring must have been original though, I could not find any fiddling on the wiring loom on the Diesel. And similar I didn't find any work done on the wiring loom of my scrap caar (and which I used now on the Diesel)

so I got confused there because in on the big plug going on the ECU they are, green and brown all for of them.
The resistance on all 4 sensors are within the 2.6 range now so that shouldn't be causing trouble. So it must be the wiring part going from my 'fix' close to the steering house and the wire that goes in the engine bay to the ECU. It is my plan to go and check again this weekend cause the weather is crap here anyhow

Hi Jaap

Both sets of wiring (ABS & electrovalve) run under the car in 8mm corrugated black plastic split tubing.
You can open the split tubing to see the wire colour.
The yellow electrovalve wires run drivers side (RHD) with the hydraulic flow and return pipes just inside the sill.
The brown and green ABS wiring to the rear axle runs passenger side with the flow and return fuel pipes.
The electro valve wire run tube continues between the sill and fuel tank end before it goes up onto the rear subframe.
The ABS wire run tube goes up over the top of the fuel tank where the tubing tees over the top of the subframe.
That is where the ABS sensor plugs are fixed to the subframe.
This ABS wiring is not accessible or visible from the "B" pillar back.
You have to drop the rear subframe to see or work on it.

John

the way I read this, is I used the wrong wire. I remember only 1 wire going inside the split tubing underneath the plastic covers and the LHM pipes.
So confusing. And how could it be, I disconnected the old (non functioning) ABS sensor (Robert had tested that and wasn't up to 2.6 K Ohm) Naturally I put the (wrong) Teves sensor on that same wire-plug. I never touched the eclectrovalve. Didn't check that wire either. Should have. So you can understand my confusion, since I cut the yellow wire in the corrugated plastic split tubing and replaced that one only and I did not drop the rear sub frame.
If I used the wrong wire, it baffles me completely because it would mean the old wire should still be there somewhere and it isn't Unless it is broken but I doubth that, it's green isnt' it..But: I did not check the colour of the ABS wiring on the other side (should have I know I know) I will have another look but I will admit I am growing weary on these kind of dirty jobs. Will keep you posted because I won't give up.

Hi Jaap, the wires are there. Green and brown twists. The plug is hard to reach. It runs over the top of the subframe. The plug is now loose since I unplugged your sensor when you were last over here.

Fingers crossed, I've got the ABS issue fixed I don't know the state of the warning light being on for so long but for now I've removed the black tape on the dash to prevent me from reminding me all the time.