Hi All smarter than me. You look lovely today

OK when driving to work on Sunday, my 2007 R52 sidewalk triggered the ABS light, Brake light and stability control was deactivated. Yikes right? Well the car handled no differently and the brakes felt fine.

I park (time passes) I get back in and start the car heading home. No lights at all???

I have gone through 4 drive cycles since the light event and everything is as it should be.

What do you think of this? I am not one to just forget about it. If I were to guess it would be a sensor or relay on its way out but have no clue as to how to proceed to check this out further.

any insights would be appreciated

Thanks

 

Search on 'trifecta' - usually an indicator of a bad wheel sensor. Can be intermittent.

 

Thank you Eric Not looking at a manual right now are there 2 or 4 sensors and any idea how to tell which one is going wonky?

 

So On reading about hub issues I am certain I have no wheel noise that is out of the ordinary. I would interpret this to mean my wheel bearings are not at fault here.

I also get a sense that there are 4 sensors (2 front 2 rear).


Plan A would be to buy a front and rear sensor install both on right side keeping the old ones. If they lights come flashing back take removed ones and install those on the left side.

Plan B depends on if I pick up an OBDII scan tool or head to my local Pepboys will a generic scanner read the codes or would I need to go to the dealer to figure out which sensor is wonky.

I am guess plan B would work but have been told that minis are not so easily read and codes cleared by using personal code readers

Thanks again

 

a OBD2 reader (typical consumer models) WILL NOT be able to access the data to tell you WHICH sensor is bad...
This may be one case it MIGHT be worth paying a shop (with the right tool) that can read it...and tell you WHICH one...a BMW shop should be able to do it for you.
The sensors can be a pain to get out..so it might be worth just letting them deal with it...just comes down to how determined you are!

 

What's the brake fluid level in the reservoir?

 

Thanks for clarifying the OBDII abilities in this diagnosis. Having recently done my front brakes, I know exactly where and how to replace the sensors so I think I am just going to go for it. I have penetrating oil & patience.

I'll call my mini dealer and see if they will read the code (and for how much). If its more than 50% the cost of the sensor, I will buy a front and rear, replace the right side of the car and if the lights return replace the left side with the old right side sensors.

Last question is I have 7-8 drive cycles with no lights. will the codes erase (or have they erased) or are they stored such that a read of the ECU data will still yield the information?

Thanks

 

perfect last time I checked (2-weeks ago) but I'll take a look this morning

 

Its probably the left front sensor. they are usually the culprit, ESPECIALLY if you've had brakes done recently. They usually get pulled on when the brake pad wear sensor is replaced. I have a scanner from CarSoft (at least that's the name on the tool) that will allow me to check abs codes. the scanner only cost $200, and works on just about every module that needs diagnosis.

 

The codes are stored, so although not currently active, a scanner will be able to pull them out.

Just a FYI, I had the same trifecta of lights when my fluid level dropped below the min line. They also disappeared and were stored.

If it's the fluid level, you can top it up with DOT4 and be good to go. Just make sure to do it, any air in the hydraulic lines is a bugger to get out.

 

Just thought I would update.

no reoccurrence in at least 100 drive cycles.

Just pick up 3 bottles of brake fluid and will be bleeding the system this week in spring maintenance. I have to conclude that the incident was a fluke.

(at least for now )

 

Sidewalksam, PM sent

 

Thanks

bleed the brakes today (finally not freezing ) all went well and still no more returning trifecta.

Will also add I picked up a honda dog-nut spare on crags list for 20 bucks. test fit the spare front and rear and it clears easily on both. It's a 15 but better than not having a spare on a long trip with the run flats a thing of the past.