ABS on 2001 Synergie

[jbgtatty]

Hello one and all. New to this lark.

Bought myself a trusty Synergie with 181K on the clock It runs sweet and looks like its been looked after. However after 3 months of no faults..... the ABS light has come on permanently and the MOT is due. I checked the fuse - 10amp - the one for the ECU and reversing lights, as the reversing were not working. The fuse looked fine but I changed it anyway and hey presto, reversing light worked again but ABS light still on. I've checked all the wiring and sockets on sensors and checked wiring for corrosion on ECU socket but still no luck. Want to avoid high costs as the car is not worth much. Any thoughts. Some advice if anyones got any to help would be much appreciated.

[Hell Razor5543]

It is most likely that a sensor has failed. I cannot help to diagnose which, as I don't know what the ABS ECU connector pinout is. I am sure that somebody will know, and post the relevant information.

I have found sensors on e-bay, both front and rear;

http://www.ebay.co.uk/itm/Front-ABS-Whe ... 589719f9b1" onclick="window.open(this.href);return false;

http://www.ebay.co.uk/itm/Rear-ABS-Whee ... 4607007540" onclick="window.open(this.href);return false;

I hope this starts to help.

[jbgtatty]

Many thanks for that. I'll start with the rears and swap them out one by one to see where the fault is.

[Hell Razor5543]

If anybody knows what ABS ECU is fitted the your car, it would help a lot. If (and I do say IF) it is the same as the one in a Xantia, this link would help;

http://www.frenchcarforum.co.uk/forum/v ... hp?t=26012" onclick="window.open(this.href);return false;

However, these diagrams would work ONLY if the ECU matches either of the ones in a Xantia, otherwise they could cause confusion.

[jbgtatty]

Ok. Bought a new rear wheel sensor and thought id'd swap the new one, with each rear one in turn to see if it was one of the rears. Tried to get the sensor off the N/S/R but the bolt sheared due to rust and now the old N/S/R sensor is stuck in place So thought i'd try the O/S/R and bugger me the bolt came out of the sensor but I could not get the sensor to budge. So out came the trusty hammer. Consequently I busted out the old O/S/R sensor and therefore had to replace it with the only new one I'd got. All successful but ABS light still on Gonna by a new front sensor and swap out one at a time to see if its a front one first. However, if its not the front ones any tips for trying to get the busted N/S/R, bolt/sensor out just in case it is that sensor that's knackered? Looks like it would be a nightmare to tap and die....

[Hell Razor5543]

Drat. If I had thought you were going to have a problem with seized bolts I would have suggested spraying the bolts daily for a week with Plus-Gas, (which is described as dismantling fluid). That normally frees up things that otherwise are considered a solid block of immobility!

If you can get to the connector while it is in situ (and get a multimeter onto it), you can do a basic test. What I would do is to read off the resistance of the new sensor, and then compare the other sensors. If there is more than a few percentage difference, then that is likely to be the problem.

PS On a Xantia, the NSF sensor is the one that fails the most.

[jbgtatty]

Thanks for that Hellrazor. My electrical skills are not that great (I'm better with a sledge hammer and chainsaw). I think I'll go for the front sensor swap one at- a- time and if I've still got the ABS light then....... I think I could drill out the bolt on the N/S/R from behind the drum back plate and through the back plate ( I can't believe modern cars are still fitted with drum brakes) - if I can get space for a drill Then I could attach any new sensor with a fresh nut and bolt.... You don't know if you don't try! And if that doesn't work, I can feel the crusher and £150 coming on.......

[Hell Razor5543]

If you can find out what the ABS ECU is (make, model, etc.) than it is possible to find out what the pins do on the connector. If it is the same as either of the ones fitted to Xantias, you can then just use a multimeter (and the diagrams I posted earlier in the thread) to find out the resistances of the sensors.