ABS Warning Light Staying On!!

brmartyn · Unread post by **brmartyn** » 09 Feb 2010, 15:31

To DickieG

Apologise if you have emailed me your contact details but I think I may have deleted your email from my spam folder by accident!

Please reply

Thanks Brady

Unread post by **Peter.N.** » 09 Feb 2010, 17:21

Front right connector I would think then, fairly easy to get at, take the wheel off and follow the wire from the sensor.

Peter

Unread post by **CitroJim** » 09 Feb 2010, 18:56

Yes, I'd agree Peter, check the connector. You'll find it nesting on the front side of the rear part of the subframe up by where the brake flexi-hose is anchored to a bracket on the subframe.

It gets covered in oil there and they do occasionally drift apart.

If not that then a change of sensor. Not too bad a job on the front. That one is the easiest...

Good work Brady

brmartyn · Unread post by **brmartyn** » 09 Feb 2010, 19:06

CitroJim wrote:Yes, I'd agree Peter, check the connector. You'll find it nesting on the front side of the rear part of the subframe up by where the brake flexi-hose is anchored to a bracket on the subframe.

It gets covered in oil there and they do occasionally drift apart.

If not that then a change of sensor. Not too bad a job on the front. That one is the easiest...

Good work Brady

Unread post by **CitroJim** » 09 Feb 2010, 19:15

Sorry Brady, fast typing and not thinking leading to confusion!

I was agreeing with Peter N that the connector was worth a check and then drifted to telling you where it is located without really making it clear who I was speaking to...

brmartyn · Unread post by **brmartyn** » 09 Feb 2010, 19:34

CitroJim wrote:Sorry Brady, fast typing and not thinking leading to confusion!

I was agreeing with Peter N that the connector was worth a check and then drifted to telling you where it is located without really making it clear who I was speaking to...

I think I'm going to have too meet up with one of you forum guys sometime soon and have a few lessons

brmartyn · Unread post by **brmartyn** » 11 Feb 2010, 12:27

Hi Guys

OK I don't want to jinx this one but from today the ABS warning light has gone off and stayed off (so far anyway, touch wood!!)

why would this be? seems strange to have a intermitted fault on the ABS. Should I still go ahead with the O/S/F sensor change or just be wary of it for now?

Unread post by **CitroJim** » 11 Feb 2010, 16:29

It does sometime happen like that Brady but so often it means the sensor is not entirely happy.

Have you checked its connector?

Also, have a look at the sensor itself and the ABS toothed ring on the driveshaft joint. Give the ring a clean up and remove any debris from its "teeth" and also clean the very end of the sensor where the pole-pieces are.

Not a bad idea to get a spare in stock but be aware that MK2 sensors are different from MK1 sensors.

brmartyn · Unread post by **brmartyn** » 12 Feb 2010, 18:35

ABS light back on today I'm not a happy boy

Looks like I'll have to buy the sensor after all

VertVega · Unread post by **VertVega** » 12 Feb 2010, 19:53

ABS light was my nightmare for sometime and it is very annoying.
Using pic which is sent by CitroJim you can measure the resistances.
It seems that front left is not giving normal readings. If they are between
1030 - 1080 ? then it can be regarded as a healthy reading.

Before replacing it, you should also measure from the sensor connector.
Sensor cable is about half a meter long, follow it to find the connection point.
It's route is almost same as the handbrake cable route.
___________________________

PS: I have unplugged the ABS ecu connector several times (~50 or more)
and without disconnecting the battery negative plug

I didn't know that it should be disconnected.
Fortunately it didn't cause any harm to the ABS ECU.

Unread post by **CitroJim** » 12 Feb 2010, 20:10

VertVega wrote: PS: I have unplugged the ABS ecu connector several times (~50 or more)
and without disconnecting the battery negative plug
I didn't know that it should be disconnected.
Fortunately it didn't cause any harm to the ABS ECU.

Just me being very cautious around automotive electronics...

VertVega · Unread post by **VertVega** » 12 Feb 2010, 20:22

Disconnecting battery is definitely the correct and proper way for this.
I had the "good luck" of a novice

I don't have to worry about any security codes, radio code but some cars do.
Only radio needs a new station scan and clock time must be set again

Unread post by **Peter.N.** » 12 Feb 2010, 21:58

If you are getting any resistance reading at all from the sensor the chances are that its OK, when they fail they normally go completely open circuit so you get no reading at all or one in the 'megohm' range due to leakage, if the resistance is only slightly high its most likely a poor connection.

Peter

Xaccers · Unread post by **Xaccers** » 12 Feb 2010, 22:17

Peter.N. wrote:If you are getting any resistance reading at all from the sensor the chances are that its OK, when they fail they normally go completely open circuit so you get no reading at all or one in the 'megohm' range due to leakage, if the resistance is only slightly high its most likely a poor connection.

Peter

Funny you should say that though, one of mine was showing 1100Ohms measuring the sensor directly.
Replaced it with a new sensor and all was well.

Unread post by **Peter.N.** » 12 Feb 2010, 22:30

Must be caused by some corrosion actually in the sensor then because if the coil wire breaks it will read O/C both of my failed ones did.