xantia ABS please help

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paulkirkin
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xantia ABS please help

Post by paulkirkin »

Have failed NSF abs sensor (so what's new?). Tried to fool ECU by connecting resistors (1028 ohms) inplace of sensor but warning light remains on after two flickers. I realise the ECU will detect a fault when the car is moving as the NSF signal will be absent but I hoped the initial test when powering up would detect the resistance, reset the ECU and turn off the light!
What I need to know is, when a new sensor is fitted, does the ECU reset as soon as power is present, or only when the vehicle is moving and signals from all four sensors have been detected?
Reason for all this is I want to replace the car asap but mot is due soon and I know what that means!
Peter.N.
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Post by Peter.N. »

It maybe because the sensor is inductive not purely resistive, I dont know what sort of load the computer offers. Once the new sensor is in place the system should function normally. mine will sometimes show a warning light and 'ABS out of use' display, because I must have a bad connection somwhere, but the next time I use it, it all works OK.
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AndersDK
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Post by AndersDK »

The sensors are simple wounded coil types. The trick connecting a 1K ohm resistor should in fact work for the initial starter key testing.
I believe you may have a connection problem somewhere in the wire run.
Or you may have one (even 2) more duff sensors indeed !

Note that the ABS ECU also tests the continuity to the ABS valve block. Meaning a loose or corroded connector here might as well set off the fault lamp.

PS : there is no sense in trying to obtain a 1028.000 ohm resistor. Any 1K ohm 10% tolerance resistor would do the job as well.
Any common multimeter at affordable price wont give you better accuracy than 3% anyway - provided you are using correct methods of measurement.
Anders (DK) - '90 BX16Image
paulkirkin
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Post by paulkirkin »

Many thanks for your comments Peter and Anders, where can I find connections to valve block and can I test these. I really don't want to fit a new sensor and find I still have a problem!
paulkirkin
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Post by paulkirkin »

Sorry forgot to mention, other three sensors measure okay. Pos supply, grounds and feed from brake pedal all ok!
zxTd

Post by zxTd »

as in my reply to the other ABS problem post (you dont mention the age/engine cc/petrol/diesel),

switch ignition off and remove the key for safety reasons now locate the ABS ECU and unplug the multi-plug,

the multi-plug is a 37 pin and is numbered, pins 15 & 30 is front left sensor pins 1 & 6 is front right sensor 19 & 28 rear left and 29 & 31 rear right,

now you need a multi meter to test the ohms/resistance on each sensor and all should read 1080 ohms approx low or zero resistance is the bad sensor,

I hope this helps
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