Where's The Nsr Abs Sensor Connector?

[Skipweasel]

From measuring at the front, the NSR ABS sensor has gone open circuit - or its connector has.

 

But - where is it? The lead appears to vanish up behind the suspension member and comes out as something else into the wiring tray.

 

Is it really up-tight and out-of-sight? Is there another way to get to it?

 

Thanks - Guy.

[techbod]

the connectors are either in the wheel arch or just inside the bonnet near the suspension struts,

 

when rotating the wheel and a multi meter back probing the leads they should give aprox 0.1 volts fluctuating.

[Skipweasel]

the connectors are either in the wheel arch or just inside the bonnet near the suspension struts,

 

when rotating the wheel and a multi meter back probing the leads they should give aprox 0.1 volts fluctuating.

 

Well, there won't be a signal as it's open-circuit. The cable changes from rubber-covered to just a pair of wires somewhere above the rear suspension member, as far as I can tell - I just wondered if there was something I'm missing. Can't see it going anywhere near the wheel arch and it certainly doesn't get as far as the bonnet.

[techbod]

ok so you need to check at the connector from the ABS ECU for the resistance of each sensor back and front,

 

the plug to the ECU is 25 pin

 

front driver side ( UK ) you give no info on what/where/engine side/age of car so ill go for UK spec on a 1.6 1999

 

front driver side is pins 19 and 20 and resistance for all sensors are 1000 ohms

passenger front = pins 2 and 2

rear passenger side = pins 5 and 6

rear driver side = pins 22 and 23

[techbod]

Wheel speed sensors

Preparatory conditions

Check wheel bearings for excessive play. Adjust or replace as necessary.

Check wheel speed sensors for mechanical security.

Inspect wheel speed sensor rings visually for damage and cleanliness.

Checking air gap

Technical Data

Air gap Not specified

No adjustment of wheel speed sensor air gaps is possible.

Checking resistance - front -

Technical Data

Terminals Wheel speed sensor Resistance

1 & 2 Left hand 1000 W approx.

19 & 20 Right hand 1000 W approx.

Ensure ignition switched OFF.

Disconnect ECU multi-plug.

Check resistance between harness multi-plug terminals If resistance not as specified:

Disconnect relevant wheel speed sensor multi-plug.

Check resistance between wheel speed sensor terminals .

If resistance as specified: Check wiring.

If resistance not as specified: Suspect faulty wheel speed sensor.

Repeat test for other wheel speed sensor.

Checking resistance - rear -

Technical Data

Terminals Wheel speed sensor Resistance

5 & 6 Left hand 1000 W approx.

22 & 23 Right hand 1000 W approx.

21 & 23, some models Right hand 1000 W approx.

Manufacturer: Citroen Model: Xantia 1,8 16V

Ensure ignition switched OFF.

Disconnect ECU multi-plug.

Check resistance between harness multi-plug terminals .

If resistance not as specified:

Disconnect relevant wheel speed sensor multi-plug.

Check resistance between wheel speed sensor terminals .

If resistance as specified: Check wiring.

If resistance not as specified: Suspect faulty wheel speed sensor.

Repeat test for other wheel speed sensor.

Checking voltage - front -

Technical Data

Terminals Wheel speed sensor Voltage

1 & 2 Left hand 0,1 V ac min.

19 & 20 Right hand 0,1 V ac min.

Ensure ignition switched OFF.

Raise vehicle.

Disconnect ECU multi-plug.

Adjust voltmeter to measure alternating current.

Turn road wheel.

Check voltage between harness multi-plug terminals .

If voltage not as specified:

Disconnect relevant wheel speed sensor multi-plug.

Turn road wheel.

Check voltage between wheel speed sensor terminals .

If voltage as specified: Check wiring.

If voltage not as specified: Suspect faulty wheel speed sensor.

Repeat test for other wheel speed sensor.

Checking voltage - rear -

Technical Data

Terminals Wheel speed sensor Voltage

5 & 6 Left hand 0,1 V ac min.

22 & 23 Right hand 0,1 V ac min.

21 & 23, some models Right hand 0,1 V ac min.

Ensure ignition switched OFF.

Raise vehicle.

Disconnect ECU multi-plug.

Adjust voltmeter to measure alternating current.

Turn road wheel.

Check voltage between harness multi-plug terminals .

If voltage not as specified:

Disconnect relevant wheel speed sensor multi-plug.

Turn road wheel.

Check voltage between wheel speed sensor terminals .

If voltage as specified: Check wiring.

If voltage not as specified: Suspect faulty wheel speed sensor.

Repeat test for other wheel speed sensor.

Checking wave form - front -

 

Technical Data

Terminals Wheel speed sensor

1 & 2 Left hand

19 & 20 Right hand

Ensure ignition switched OFF.

Raise vehicle.

Disconnect ECU multi-plug.

Connect oscilloscope between harness multi-plug terminals.

Turn road wheel.

Check wave form of wheel speed sensor.

If wave form not as specified:

Disconnect relevant wheel speed sensor multi-plug.

Turn road wheel.

Check wave form between wheel speed sensor terminals.

If wave form as specified: Check wiring.

If wave form not as specified: Suspect faulty wheel speed sensor.

Repeat test for other wheel speed sensor.

Checking wave form - rear -

 

Technical Data

Terminals Wheel speed sensor

5 & 6 Left hand

22 & 23 Right hand

21 & 23, some models Right hand

Ensure ignition switched OFF.

Raise vehicle.

Disconnect ECU multi-plug.

Connect oscilloscope between harness multi-plug terminals.

Turn road wheel.

Check wave form of wheel speed sensor.

If wave form not as specified:

Disconnect relevant wheel speed sensor multi-plug.

Turn road wheel.

Check wave form between wheel speed sensor terminals.

If wave form as specified: Check wiring.

If wave form not as specified: Suspect faulty wheel speed sensor.

Repeat test for other wheel speed sensor.

 

Manufacturer: Citroen Model: Xantia 1,8 16V

Engine code: LFY (XU7JP4) Output: 81 (112) 5500

Tuned for: R-Cat Year: 1995-01

[Guest Yorkshire Xantia Owner]

I've got the same problem on a 1999 Xantia 1.8i 16V Estate. Two of the sensors (rear left and front right) measure about 950 ohms, front left measures about 2000 ohms and rear right 50 ohms. I have checked the two odd values at the ECU plug and at the sensor plug and confirmed that the problems are with the sensor and not the wiring.

 

Is a sensor with a resistance of 200o ohms likely to be working? I have tried to see if rotating the wheel generates a signal, but my basic mechanical multimeter is not sensitive enough.

 

My other problem is that I cannot remove the rear sensor. I have removed the retaining bolt OK, and the small protective shield has disintegrated, but the sensor itself is completely stuck. Any ideas on how to remove it?

 

Skipweasel - on my car the rear sensor connector was located on the top of the suspension member directly above the rear suspension globe. Quite easy to reach with the rear wheels on ramps.

[techbod]

in most cases the sensor has to be broken to get it out due to corrosion,

 

Is a sensor with a resistance of 2000 ohms likely to be working? no.