ABS Break lights ON
 

I have a 2001 X5 4.4i. 130 miles after the two front axle assembly replacement, ABS and Break light comes on, Speedometer stopped, Techometer momentarily working, temp needle goes to max. After some web search, I decide to test the ABS Speed sensors myself.

After disconnecting the sensor connector in the wheel well, I measured the voltage coming out of the ABS module:
0V - ignition off; 2.8V - ignition key pos 1; 2.5V - ignition pos 2.

Measured the resistance across the sensor terminals:
Left front - 8.5MOhm; Right front - 8.2MOhm.

Attached a scope to the sensor output, spinning the front axle, I do not see any pulse coming out of the sensor.

Removing the sensor from the hub assembly, found iron powder on the sensor tip. cleaned sensor tip. Placing a magnet at the tip of the sensor and moving magnet, barely see any voltage change.

Looking into the sensor hole, spinning wheel, I do not see anything different after 360 deg rotation. It was just a metal drum. So what causes the sensor to pickup signal?

Now I am wondering if the sensor is bad, or installation of the axle causes the hub assembly to fail? :whistle:

Thanks in advance for your help!

//Leo

Leo,
I just had to replace my wheel speed sensor on my '01. I had some of the same symptoms as you, speedo would not work, ABS light on, brake light on and also traction control light on. The only thing is that the wheel speed sensor is actually on the right rear wheel. I believe that all the wheels have ABS sensors, but the speedometer is controlled by the right rear wheel. So to answer your question if your installation of the front axles would cause this, I would think the answer would be no. I have heard of some of these symptoms also being caused by a faulty ABS Control Module, which I had mine rebuilt also. If someone else has any more to add please chime in. Hope this helps.

Todder

Hi Todder,

Thanks for the response. I posted and paid for an answer at www.justanswer.com. The answers I got back were
1. Speed sensor is on the left rear.
2. The problem is not likely the ABS sensor, but the instrument panel cluster since techometer and temperature meters were off. Need to run a diagnostic to pin point the problem.

I did not get an answer on if the sensor resistance was within spec. In addition, I also measured the left rear - 4.5MOhm, which is half of the front wheel sensors. Anyone knows if the sensor is OK? Thanks in advance for your help.

//Leo

does the trans fail safe prog come on? i have the exact problem that you have except i have the trans message flashing every second and my acceleration is sluggish. my car is currently at the dealership i'll let you know what they found out about my car..if that helps

2001 X5 4.4 Break ABS lights on
 

I do have the "Trans Fail Safe Prog" and sometimes "Engine Fail Safe Prog".

After I posted message, for two days, each morning when I first start the car, everything seemed to be normal, only "Engine Service" light on. But after driving 10 - 14 miles, the gauges stop and lights are on, Trans going into fail safe mode which is the 3rd gear (it makes acceleration sluggish, best to drive at 45mi/hr). Other symptoms in fail safe mode: Temperature gauge works momentarily (sits in red most of the time), techometer works momentarily, instrument display goes into dimmer mode and intensity not adjustable.

It makes me think the failing has to do with some timer or temperature. When cold everything is OK.

I will take it in for a diagnostic run next week when my friend has time. Will update the findings.

In my personal experiances and observations with E53's, faults for wheel speed sensors go like this...

Either front sensor, usually just the sensor.
Right rear sensor fault usually the DSC module.
Left rear sensor faults usually the Instrument cluster.

As for diagnosis, I think you are looking too deep, these measure fron the side of the tip from the back of the wheel bearing, and the micropulses are harder to read even without a graphing ocilloscope due to the size and frequency. Just simply read which side the sensor fault is on, swap the sensors left/right for either respective axle, clear faults then drive. If the fault followes the sensor, replace the sensor. If it stays in the same position, check the wires between the sensor plug and the DSC module if needed before buying the components mentioned above.

That is the good thing about both sensors being the same for each axle, just swap them for diagnosis.

This is the methods I used when diagnosing my own truck (which needed a DSC module, r/r sensor fault) and my mothers E39. (which just needed a front sensor)

Since instrument cluster was in question, I had the cluster replaced since it was loosing pixels. Parts covered by BMW USA good will program, I paid labor. The error did not go away, so engine diagnostic showed DSC module error, electronics part. BMW would not cover the DSC module cost. I could have the DSC unit rebuilt, but that will put me out for a week and I need the car for prearranged business.

It turn out to be a VERY expensive repair. It could be worse without the BMW good will.

Is it ABS or DSC module?
 

Good write up. My car operates normally for first ten minutes, then ABS and
DSC yellow lights and red Brake lights come on. The Speedometer also goes out when the lights come on. I have checked and cleaned
ABS sensors before when I had similar problems which corrected issue.

In reading info on the modulemaster website they seem to think it is the ABS module which they will rebuild for $300. I've heard talk of the steering angle sensor.

What symptoms if any does a bad DSC module exhibit??

Thanks for your help! PS I have 218,000 on my 2001 X5 I bought new.

The steering angle sensor wouldn't have anything to do with the speedometer, so you can scratch that of the mental checklist. As for the bad DSC, they all fail individually and will exibit slightly different symptoms. If you want to be extra sure it isn't just the sensor you can swap it with the right rear and se if the fault follows.

As far as the left rear sensr circuit quitting, causing the speedometer to quit... It could be the cluster or the module, you got a 50/50 chance. I'd consider having diagnosis done by the dealer (and ask for a master tech) to see if there are any CAN bus faults as often the the module dropping out can cause can communication faults to be stored. The dealer has enough diagnostic resources to be able to better know which it is causing the issue through testing.

I've been thinking it is the ABS module
 

modulemaster's website made the comment that if the car operates normally and then the lights come on and the speedo goes it is temperature related.

Mine works fine until it comes up to temp, maybe 10 minutes. Then speedo goes and lights come on. It seems if it were a bad sensor this wouldn't be the case.

What I don't know is BMW control logic. It must be polling devices on some regular basis at some pre determined interval. If they fault once some circuits need to be cleared, like oil change interval. In my case I'm just wondering if there had been a transitory fault it has been stored in the computer and will keep showing lights until it is cleared. Then I wonder if nothing is wrong, just the fault circuit.

At my mileage I don't really care about ABS. I have a GPS so I know my speed anyways without a Speedometer......just kinda annoying when stuff doesn't work. To show my mentality when my check engine light came on years ago I did the gas cap thing and in the end put a piece of black electrical tape over it. Ditto when the airbag warning light started to come on intermittently........more black tape........may have to get it out again!

I like the BMW ride, but I do think the complexity of their electronics and their propensity to fail after 100,000 miles really detracts from the vehicle. The motor and transmission have been bullet proof other than all the oil gaskets that had to be replaced.

2001 3.0 with manual transmission, ~170K miles: ~5K miles ago, DSC and ABS lights came on, speedo and odo stopped functioning; cruise control finally stopped functioning, so I checked the RR wheel speed sensor. Broke it in the process, so replaced it. Cruise control functioning again, but still no speedo or odo. Sensor swap (right to left) next.

To wrap up the posting, I got my car back. With instrument cluster and DSC replace, it is like new again, I am happy.

At almost 110K miles, what would be the next to go down. I checked some complaints website, I hope it will not be the transmission!!! Any comment there?

Oil Separator and Oil filter housing gasket
 

You will undoubtedly have your oil separator and oil filter housing gasket go bad. You'll see oil leaks as symptom and start putting oil in. My hose from separator to oil dipstick tube literally rotted off......... Oil filter gasket is
a $5 part but you just about have to disassemble the motor to get to it.
It is where the oil filter housing mates to the block. It was super brittle just like the valve cover gaskets I did at 187,000 miles. Yeah, they're going to go too.

If you haven't switched out your water pump and thermostat I would consider putting that on a PM list. My Indy did the first one at 100K and we found the bearing about to go. We did Tstat and water pump at 200K after radiator reservoir went and found the Tstat looking bad seal wise.

If your car starts to stall off the line do the intake cam shaft sensor. Mine was bad for 1.5 years before I figured that one out. When I replaced it cleared up fault and I got my power back. The VANOS was not working and the motor was in a default mode.

I also had wheel bearing go in left rear, 3 CV joints and the transfer case.

The transfer case will make a mechanical click sound as you start off. Go the rebuild route for $800 or so rather than the $2000 the dealer wants just for the part. My Indy rolled his eyes when I did this with non OEM part, but 2 years later it's running fine. These are simple devices, just gears and bearings that go. I think they got rid of them on later models.

Of course you will be dealing with window regulators, AC resistor fuses, brakes and rotors, etc.

Your belts along with the idler pulleys will also go. You have to buy the whole assembly just to get the gear for both tensioners......thanks BMW.

Plenty of plastic parts break, sun visor, center console latch, window shade holders, back cup holder, etc.

My newest expenditure is $300 rebuild of ABS module by module master in Moscow, ID. Their website is very informative. My DSC, ABS and Brake lights are on and my Speedo/ODO/Cruise is out.

I would not own a BMW out of warranty again. I have become somewhat of an expert (I think) on the I6 3.0L, but it fails too much for me in comparison to the multiple makes of Japanese cars that I've had. None of them experienced this level of failure in basic components.

BMW IMHO has a very slick mkt strategy - they sell to the 3 year lease crowd and those who trade before warranty expires. They are super happy customers. The 2nd set who keeps the car or buys them used get to deal with $$$ of repairs and gives them tremendous service/parts revenue flow.

If you love wrenching and buying expensive German parts this is the car for you!

Thanks for the extensive write up. I got "long way" to go ...... Wrenching is not for me.

Some recommended Lexus LX470 or Acura MDX to me for reliability. I have not test driven them, just from the look of these, they are different bread.

Lexus and Honda
 

I bought an LS 400 Lexus when they first came out in 1989. My factory was in Torrance just down the street from Toyota.
I paid $39,995 for that car, drove it for 77,000 miles and only replaced the
tires. That car had ZERO issues. None of the crap I've experienced with BMW.

BTW I also had a 1990 BMW 3.0 convertible, traded it at 40,000 miles, just a few problems. I had a 1996 BWM 3.0L sedan. Lots of issues. Got rid of it at 107,000 miles before it got out of hand.

Like I mentioned above, BMW has a satisfied customer group that it markets new cars to. The rest are on their own!!

The Japanese and German mentalities are very far apart in philosophy. The US is somewhere in between. The Japanese will strive for perfection even if they don't get an immediate return. Look at the numbers over the last 30 years and it tells the story...........

Mass Air Flow sensor - the best one!
 

Oh, I forgot the best one of all! I got suckered into replacing the $425 air mass sensor plus $85 one hr svc. You can switch it out in under 2 min!!

The symptoms are rough idle and it throws fault codes. There are some platinum wires in there close together. They get dirty from dust and soot.
One of my jetski buddies heard me complaining cause the car was doing it again after the sensor had been replaced a year or so ago.

He said go to auto parts store and buy CRC air mass sensor cleaner for $3.00.
It WORKED perfectly! Every time it starts to act up you literally open the sucker up and give it shot and it fixes it!

Here is my story. At 90k miles, my Indy changed bunch of intake parts before identified the mass air flow sensor. I bought it online for $350 and he put it in at no charge, after some $500 unnecessary replacements!

Thanks for the feedback. It is time to give up the "pride" and performance. Even the new X5s, there are reports of excessive battery leakage (due to electronics), engine stalls, sudden acceleration, etc. The percentage may be less than the earlier X5, but still. My 2001 X5 the first year, I took in 6 times, second year 4 times, ..... Very inconvenient, even under the warrenty.

I went through the BMW factory in SC
 

Very impressive factory, over 500 robots. The components made in Germany are definitely more reliable, ie motor and transmission. Even so they do fail more often than competition. Just like those stupid graffite brake pads that dust up. You might get 10% more performance in repeated panic stops. Otherwise you clean wheels your whole life. I went for metallic pads early on and never washed brake dust off again, NON BMW pads by the way.

I would get rid of your car and save yourself countless hours and $$$. I wish I had of done so.........I kinda got sucked in to just one more fix and it will be good........Once I get a little money together I'm parting this mother out. Got to be worth $25K! Just think about all the body parts! Can you imagine the bill from a head on at say 25mph?? forget about it!!

Take a different spin on "You might get 10% more performance in repeated panic stops", that applies to much more beyond the break pads! Right after I got the X5 out of the shop, my wife's 330ci traction warning light came on. It has 80K miles, and I am afraid the DSC module, again, on 330ci. My wife does not know much about the car, and she had a "panic stop" on the warning light!

The ABS sensors work using the "Halls Effect". It was a big hassle trying to diagnose which one of mine went bad, therefore I changed them all out.

Quick question regarding the foregoing thread: where are the ABS sensors located? Are we talking about the brake pad sensor?

My problems started with the Engine Failsafe Prog, which disappeared, and then the DSC, ABS, break yellow failures.