New ABS sensor or coding?

Isambard · #1 02-09-2013, 02:02 AM

Hi All,

I changed my front wheel bearings yesterday and in the process, slightly damaged (put a chamfer on one side-but didn't break through the plastic) one of the ABS sensors.

I've driven down the road expecting the ABS lights to go off, but they have remained on.

Two questions:

1. Have I damaged the sensor such that it needs to be replaced and does not require coding again?

Or, 2. Does it just need the ABS module to be coded again because I disconnected the ABS sensors?

If anyone asks or is remotely interested, I didn't remove the sensor from the hub as they were stuck in there good (probably since the car was born some 116k miles ago) so didn't want to damage (ha, the irony!) them trying to get them out.

Cheers

TerminatorX5 · #2 02-10-2013, 01:55 AM

when you say ABS sensors, do you mean brake sensors (one front left, one rear right), or speed sensors (one at all 4 corners)?

the brake sensors are a simple electrical loop that once cut through by the reduced material of the brake pad, opens up an elecrical circuit and sets off a "brake pad worn" indicator. once the pads are replaced and new sensors are fitted, the warning goes away in a few moments.

The speed sensors are Hall Effect sensors that use touchless magnetic field from the wheels and they generate square pulses that are read by the ABS module in the engine compartment, compared from each corner and then the ABS module reports the speed into the car's iBus, where it is used to control the speedo ( a specific sensor), the odo, the engine's RPMs, the speed of the windhsield wipers, the volume of the radio, the TV function... when replaced, no coding is needed... the sensor operates as a diode - current passes in one direction and not in the other...

if you put a "dent" into a Hall Effect sensor, you may have damaged the diode inside... test it - do you have a multimeter with diode function?

Isambard · #3 02-10-2013, 04:21 AM

No, not brake sensor, thats a completely different animal. It must be what you are referring to as the speed sensor-I assumed it was the ABS. BMW call it a pulse generator.

If you're correct in that they don't need coding, and as it is a hall effect sensor then yes I have damaged them, and for the sake of 30-40 bucks each I may as well replace them. Not much point in testing them-getting under the car twice.

Thanks for the input TX5

Valentin DeCastro · #4 05-18-2013, 09:54 PM

well here I am.Ihave my 2001 X5 e53 3.0 My problem is ABS/DSC BRAKE LIGHT ON AND ALSO THE TRIANGLE .THEY COME ON AND OFF.SOMETIMES NO LITES FOR 2 OR 3 DAY.THEM BACK ON.THIS HAS BEING DO ING THIS FOR ABOUT 3 MONTH.DO YOU THINK IS THE PUMP OR THE MODULE IF SO WERE CAN I SEND IT FOR REPAIR.THANKS I HAVE READ YOU GUYS FOR YEARS.

TerminatorX5 · #5 05-18-2013, 11:29 PM

Isam, long time no posts - have you resolved your issue?

Valentin, what you have, sounds like a "trifeca" issue...

this problem can be related to the heat in the engine or to some other factors, such as faulty speed sensor... if you are planning to troubleshoot it yourself, then you need to monitor the issue and watch when it happens, and if you can correlate the problem to any external factor... and then get involved into the wires...

or, you can look up on the internet (ebay, for example) repair services that will repair your (possibly) faulty ABS module and give you a lifetime warranty... if the module is not defective, they will not charge you. you will have to remove the module yourself and send it out...

if the problem is not the module, then you might have the faulty speed sensor - you will need to test the sensors to see which one is at fault... or, you can have problems in the wiring, between the sensors and the ABS module...

there is only ONE way for it to work right and a million ways to go wrong...

time to start troubleshooting...

PS. welcome to the active side of posting to the forum - we like keeping conversations going... just lose the CAPS, some folks may get offended...

Ricky Bobby · #6 05-19-2013, 09:36 AM

Isam,

I just did my wheel bearing on the right front side and unlike you I removed the sensor (gripping with needle nose pliers and pulling out straight worked for me), left it hanging and cleaned out the bore before reinstalling. I also sprayed Electronic cleaner on the sensor and coated with Dielectric grease before reinstalling.

If you "damaged" the sensor and are sure of that, replacing the sensor will cure your problem as the new sensor can just be plugged in, they don't need to be "coded to the module"

If you had the "trifecta" of lights before changing your wheel bearing, further troubleshooting is in order to see what codes you are throwing....

Isambard · #7 12-21-2013, 10:08 PM

TX, RB, sorry for the lack of posts, been busy with work and life in general. Got a company vehicle with new job, so the X has been idle for a while. Hence me not looking at it in a while and reporting back.

Though, I've just started a massive maintenance campaign on him (pulled the intake manifold, valve covers, and valley pan, belts, waterpump, oil separator, CVV, radiator front mounting plate, hoses etc. will be replacing rear suspension after) then I'll be hitting the ABS issue again in the new year.

Since doing the bearings and fitting cheapo chinese crap sensors the speedo stopped and I got the trifecta within 10 miles. I threw the chinese crap out and ended up fitting Meyle sensors all round but still the same issue. It was ok for a few miles then came on again. Not sure if I've put too much anti-seize in when I did the wheel bearings and it's caked up the sensors.. Will check and clean thoroughly when I get to it.

Reading a few other posts lately there has been talk of battery issues relating to speedo and trifecta. I know ytour stance on this TX but I've had the battery for a couple of years (not old), BUT I had the X shipped to Aus and the shipping company forgot to disconnect before putting it on a boat for 6 weeks. I finally took delivery of my boy 2 months later

but of course the battery was flat as a pancake. Needed two full days on charge to recover. It's a bosch 'silver', so I thought it would be ok. However, I've let him stand for the odd week or two here and there (away with work) and he's been flat as a pancake again. So, my guess is I've buggered the battery by now, so I'm thinking (praying) it's just that. Obviously if its not I'll be hitting up the diagnosing..

I will be replacing the battery in the new year once I finish all the jobs above (just waiting on a few parts to come from the US. AUS prices are think of a number and double it!!), still pull the hubs and clean any evidence of excess anti seize, and cross my fingers.

RB, on a side note, I had to drill out two of the sensors as they were rusted in-they were in there like they grew there!! The others I managed to knock out albeit damage them as a result. Nothing like a bit of good ol' English rust on a 110k mile motor!

Isambard · #8 12-21-2013, 10:17 PM

Joyous times..

Isambard · #9 12-21-2013, 10:19 PM

The breakers yard!

TerminatorX5 · #10 12-22-2013, 12:13 AM

Isam, that work is impressive... not sure if your tearing down goes that far, but you may consider doing an R/R on the chain guides, since you've got the M62 - my 4.6 M62 kicked the bucket due to the chain guides... the failure was so catastrophic, that the metal housing of the engine just broke in pieces...

as far as battery goes... i've shipped my car around, and the shippers did disconnect the battery, but it was the crude way, they dug into the rear tire area and disconnected the battery... the battery still was flat after the first shipment but was ok after the shipment to Russia... after reconnecting the battery though the nav system was fried...

once a battery goes dead, in my non-scientific opinion, it is compromised... lol...