Hey, ive problem with my abs, ive located the fault to my left rear abs "magnetic/mechanical fault". Ive changed sensor, ring, and measured the voltage that comes to the sensor and its same as on the right side that works fine.I read some thread here that the stub axle gets rusty and sensor wont work, and yeah mine is bit rusty but i dont see any reason why it couldnt read the magnetic field from the ring, I also have tried to move the clip that holds the sensor on the ring but nothing works, any better ideas anymore?
Renault clio rs 197 ABS/ESP
- Thread starter Ode
- Start date
Extend the wires from the left sensor wiring to the right sensor, if it then works in parameters on a diagnostic pc for the left sensor you can eliminate pump, wiring and plug, so it’s either sensor spacing or ring spacing etc
We used to see the odd pump that died on Peugeot’s and I suspect these will be Bosch units also, so very possible to be a pump issue if all else fails!
We used to see the odd pump that died on Peugeot’s and I suspect these will be Bosch units also, so very possible to be a pump issue if all else fails!
Yeah i guess i have to try that,i tried to measure the voltage from the connector that connects to the abs sensor but i got weird volts and ive no idea what or how its actually supposed to be done. Today i did some adjustment to the sensor holder and took off some rust all around the stub axle if that doesnt do the trick i guess i have to try that trick you just told, running out of ideas unless the sensor is so damn sensitive that i really need whole new stub axle that has no rust and is perfect fit. These are the pics before i adjusted or cleaned any rust.
Attachments
Try swapping bits left to right, the sensor should remove metallic deposits stuck to the magnetic ring, we used to have massive issues with 307’s with rust under the sensor where it bolts down, it cammed the sensor tip away from the ring and gave all manner of dubious readings, a copper sealing washer was all it took to space it back if cleaning didn’t cure it... did hundreds of cars over 10 years, same with cracked front and rings
If you swap rear discs and rings swap pads keeping inner and outer the same as well
If you swap rear discs and rings swap pads keeping inner and outer the same as well
Well the disc/ring is new, its not directly from renault but it has the same OEM number. Have to try swapping everything from left to right
I’d start by running a pair of wires from the car side of the plug to the sensor on the opposite side, if you get readings you know the wiring is ok, if you don’t its either the plug or wiring (see below)
You say you’ve measured the voltage from the sensor, it’s a weird one, you may see something on and oscilloscope with the disc turning, but a normal multimeter will be all over the shop
It’s an ac (inductive) sensor, so it generates its own voltage so in effect you won’t see anything constructive on a multimeter, you may well see a trace voltage from the abs pump side which can be an indicator the wiring is ok...
the only true way to check the wiring is to unplug at the abs unit end plus the sensor end and add 12v and earth and add a h7 bulb at the other end of the circuit, if the bulb lights wiring is ok... a resistance test is fine for a quick check if you short out the plug end... but... one strand of wire will give a positive result on a resistance check, whereas a single strand of wire on a load check with a h7 (55w so just under 4A) will generally fail.
If it fails take a single core extension and run it down the side of the car and test each one individually, if you have wiring diagrams with plug pics on find the middle connections and test either end the same way
This one was a freak one off!!! I have had one instance where it was the plug on the end and me putting link wires in for a load test hit a different part of the plug and gave a good result, but the pins were damaged where they made contact with the abs sensor plug pins, sucked that one as it threw up a massive false positive and needed a new plug but all appeared good, sent me off on a right merry goose chase!
If the wiring is ok with a load test and swapping left to right and vice versa doesn’t work it then either plugs (incredibly rare!) or the abs module itself (more likely)
If it’s an abs module it’s sometimes possible to buy just the module and unbolt/bolt back on... if your unlucky it’s a pump and you’ll need to bleed it all
I suspect yours will be either a gap issue or a sensor (I’ve had two brand new sensors that looked identical on a vag, and one worked one didn’t on a Passat, both sensors were new!) or maybe a pump
You say you’ve measured the voltage from the sensor, it’s a weird one, you may see something on and oscilloscope with the disc turning, but a normal multimeter will be all over the shop
It’s an ac (inductive) sensor, so it generates its own voltage so in effect you won’t see anything constructive on a multimeter, you may well see a trace voltage from the abs pump side which can be an indicator the wiring is ok...
the only true way to check the wiring is to unplug at the abs unit end plus the sensor end and add 12v and earth and add a h7 bulb at the other end of the circuit, if the bulb lights wiring is ok... a resistance test is fine for a quick check if you short out the plug end... but... one strand of wire will give a positive result on a resistance check, whereas a single strand of wire on a load check with a h7 (55w so just under 4A) will generally fail.
If it fails take a single core extension and run it down the side of the car and test each one individually, if you have wiring diagrams with plug pics on find the middle connections and test either end the same way
This one was a freak one off!!! I have had one instance where it was the plug on the end and me putting link wires in for a load test hit a different part of the plug and gave a good result, but the pins were damaged where they made contact with the abs sensor plug pins, sucked that one as it threw up a massive false positive and needed a new plug but all appeared good, sent me off on a right merry goose chase!
If the wiring is ok with a load test and swapping left to right and vice versa doesn’t work it then either plugs (incredibly rare!) or the abs module itself (more likely)
If it’s an abs module it’s sometimes possible to buy just the module and unbolt/bolt back on... if your unlucky it’s a pump and you’ll need to bleed it all
I suspect yours will be either a gap issue or a sensor (I’ve had two brand new sensors that looked identical on a vag, and one worked one didn’t on a Passat, both sensors were new!) or maybe a pump
I have inherited this same issue today! The car will not start and the ABS and ESP lights come up on the dash, with the car refusing to turn over and start. @Ode I know your issue was a while ago, did you find a fix for it? Has anyone else experienced this before and what was the solution? Cheers. 
