[Warning Light] ABS Sensor

[geoff]

  I have the ABS light on my van dash and a pulsing / banging through the brake pedal. 

My cheapo hand held diagnostic code reader doesn't register any fault even though the dash fault light is on.

Visual check revealed nothing but going around each wheel sensor with a multi meter to check impedance gives the following results :

NSF :  3.79 M Ohms

OSF :  3.68 M Ohms

NSR :  5.27 M Ohms

OSR :  3.75 M Ohms


 These impedance readings are higher than I expected ( thinking of thou's rather than meg's ) but clearly there is a significant difference in value of the NSR at 5.27 M Ohms which to me would indicate this sensor would require replacement.

Before my wife will grant permission to spend can anyone suggest the best place to buy a sensor from please, eBay seems to sell these from around £17 but as yet I'm unsure which one to buy as my vehicle - a '55 plate 1.9D van - doesn't often show on listings.

Of course if anyone has a part number that would be even better.

       Geoff. 

[brajomobil]

  I have the ABS light on my van dash and a pulsing / banging through the brake pedal. 

My cheapo hand held diagnostic code reader doesn't register any fault even though the dash fault light is on.

Visual check revealed nothing but going around each wheel sensor with a multi meter to check impedance gives the following results :

NSF :  3.79 M Ohms

OSF :  3.68 M Ohms

NSR :  5.27 M Ohms

OSR :  3.75 M Ohms


 These impedance readings are higher than I expected ( thinking of thou's rather than meg's ) but clearly there is a significant difference in value of the NSR at 5.27 M Ohms which to me would indicate this sensor would require replacement.

Before my wife will grant permission to spend can anyone suggest the best place to buy a sensor from please, eBay seems to sell these from around £17 but as yet I'm unsure which one to buy as my vehicle - a '55 plate 1.9D van - doesn't often show on listings.

Of course if anyone has a part number that would be even better.

       Geoff. 

Can you check for error with lexia? Front driving side sensor is sending the speed of the car to the abs.
Sometime it fails and sends wrong speed to abs and abs is not working, and also there is no errors on code reader.

[geoff]

Having been so busy lately I ended up taking the van to a local garage ( first time for many years ) and they couldn't help.

I then went to a Citroen main dealer and they couldn't get any useful diagnostic data and could only give advice that involved wholesale parts replacement - diagnosis by substitution. This I can do myself and declined their offer as my labour is free of charge.

I have decided to get myself a Lexia set up and make headway that way, the equipment should be useful going forward anyway I'm sure. Thanks for the advice Brajomobil.

[brajomobil]

Having been so busy lately I ended up taking the van to a local garage ( first time for many years ) and they couldn't help.

I then went to a Citroen main dealer and they couldn't get any useful diagnostic data and could only give advice that involved wholesale parts replacement - diagnosis by substitution. This I can do myself and declined their offer as my labour is free of charge.

I have decided to get myself a Lexia set up and make headway that way, the equipment should be useful going forward anyway I'm sure. Thanks for the advice Brajomobil.

If your main dealer couldn't get useful info then getting Lexia would not help you a lot. Better borrow/buy an oscilloscope. Test the sensors while driving.
I have attached info. Hope it helps.

  abs_sensors_scope_test.pdf (Size: 227.38 KB / Downloads: 43)