Hi guys

Im the proud owner of a sapphire cosworth, I have all of a sudden got a problem with my abs. I switch the ignition on as normal and here the pump going (even though its sound different than usual or maybe its me being paranoid!) start the car and the abs light stays on. I also noticed that the first few times that i touch the brake pedal it seems to want to jump back at me! Does that make sence?? I have bled the brakes out from the calipers and all seem normal, No air in the fronts and the fluid flys through at the rears! The brakes seem to work normally when driving but the light stays on constantly

Any ideas or suggesitions would be apreciated!!!

Thanking you in advance!

J

 

First port of call - its nearly always a wheel sensor or sensor connection.

Check the connections under the bonnet (white plastic connectors that sit on top of the rails) first if I were you. Lift the rear seats and you'll find the rear pair easily.

Pull them apart and clean them up... or maybe even simply reconnect them and test each in turn if you are in a hurry - you can always return to the dodgy connection when you know which one it is.

Next step would be to remove each one in turn and check for crap. They can be tight so once the bolt is removed twist until the O ring seal frees up.

If you still have no joy check the control unit under the dash - rarely hear of them being a problem.

Last of all you will need to either test each sensor or replace them in turn. front and back are different unfortunately.

I had very similar issues a few months back and a clean up sorted it thankfully.

Think Tabs or someone on here knows the resistance test for the sensors.

Anyone else got any ideas?

 

Top info there mate.

 

Wheel Speed Sensor Circuits

1. Ensure ignition switched off
2. Disconnect ECU multi-plug
3. Connect ohmmeter between harness multi-plug terminals listed below:
LHF: 7 and 25
RHF: 5 and 23
LHR: 4 and 22
RHR: 6 and 24
4. Resistance should be 900 to 1400 ohms
5. If resistance not as specified:
- Disconnect the appropriate wheel sensor from the car loom.
- Measure resistance across wheel sensor at plug on end of sensor.
- If outside above range, replace wheel sensor.
- If OK, check wiring between sensor connection and ECU.

 

Love it - nice one Jon mate. A solid logical answer with all the details I missed.

 

The one most important missing bit is the sensor ring, these allways get overlooked despite having the hardest time, covered in rust shit crap etc, make sure each ring has clearly defined segments, as that is what the sensor needs to see, apart from that as above, note I do not think your problem is a ring but would check these anyway, it is most likely as said a connection somewhere, you can be certain it will be the last one you look at though!!
Good luck.
tabetha

 

what about the pressure switch in the servo? (big green anodised yoke) Anyone had bother with it?

I've an intermittant fault, and would like to do a complete system test if possible.

 

Blimey, forgot that!! One of the rs500 owners had to tap his the other day at Santa Pod to get it to work. Likewise I'm sure i heard of one problem where it turned out to be the fluid level switch wires damaged - is my memory playing tricks or could that also do it?

Tabs comments are also spot on - aint simple to recall all this stuff - must be my age!!!

 

Hi guys


Firstly Thanks for all the replies, Nearly everything that you have said makes sense and i have loads to go on! I have started taking the sensors out and cleaning them, I noticed that the front abs rings (in hub) have grease on them. Would anyone know if this is normal? Was going to spray some carb cleaner to get rid of it but thought id better check before doing something silly!

Cheers

And again thanks for all of your help!!!!

J

 

Check the plugs and wiring on the res cap m8, mine had a loose connection on one wire on the square plug and the light stayed on.

Steve

 

Dont think it was you Steve but glad my mind wasn't playing tricks.

Grease is good, crap in it isn't J mate. As tab mentioned, take a peek inside to see if the grooves are nice and clear in the ring - looks like gear teeth and should have clear top edges for the sensor to read.

 

Should be no grease on the sensors. its quite common issue when CV boots split all the grease gets into the ABS/ wheel sensor and brings the ABS lights on

 

On my reservoir I need it 3/4" ABOVE maximum when pressurised otherwise the abs/fluid low light comes on sometimes, obviously thought it was a sticking float in the cap assembly but no that's how mine is made/calibrated.
Cozmeister had probs with his wiring on cap but can't remember what, should be doing his poly bushes today/sunday so will ask him to post.
tabetha

 

Hi


Again thanks for all your replies, I seem to have lots to go on and will give it a good go over the weekend & monday and will let you know how i get on. Would anyone know what pins on the abs module (ecu) does what?? If not then dont worry just thought it might make life easier!


Cheers & enjoy your weekend!

J

 

Thats the first thing i'll be trying then as mine seems to come on when you accelerate hard (fluid obviously moves back). Mines sitting right on the max line at the moment.

 

Stick a bit of wire in by the plug and bridge the connections then try it - that way you will find out immediately

I have a light clean grease on all my abs sensors, not a problem at all and its not escaping grease from the hub. Shouldn't it be in there as it doesn't half make them easier to remove carefully?

I just put a clean grease smear on as that's how I found it when I stripped her down after 4 years being idle. As said - it all works fine??

 

Silicone grease would be best and not affect anything.
tabetha

 

Good idea

 

Good infos there, gonna check mines, as I had few probs last time with them. Haven't run the car for 3 years now so maybe it solved by itself haha :P

 

Just a little update, bled my brakes and mine now seems to be fine! However i also fitted new driveshafts front and rear, so cleaning the sensor rings could have been the solution lol

 

Should the 2 lines on the bottom of the sensor (on escort) be parallel with the rings on the drive ? My ABS light was coming on over 20mph and when we took out one of the sensors the 2 lines were at an angle to the rings. Can't see any other problem. Made shit of one sensor getting it out so couldn't put it back straight to check. Will have to get a new sensor.

 

Bah, get out of here with your new fangled Escort - Sierras are where its at!

On a serious note, i think the sensor can only go in one way? The small screw holds it in the correct position?

One thing though - Escort sensors have a different connection that sierra ones, so if you get a new one, make sure its correct.