On-board diagnostic, anti-lock brake system, tyre pressure monitoring, and driving stability control indicators

[Treeri]

Every once in a while for the past two weeks, the traction control light has been flashing on and off. Typically, it happens as you exit the same intersection. I didn't give it a second thought because, as with other automobiles I've owned, I assumed it was only a warning that it had kicked in due to the rain and greasy roads.

Today going home from work I decided to take the car for a run as it's been a while. Strangely, the light turned on whenever we were travelling in a straight path. The moment I got on the highway, every light went out. I proceeded at a leisurely pace for the last 10 miles because it appeared to be driving and braking normally.


When I returned home, I scanned the vehicle and now I have the following:

wheel speeds as reported by EGS CAN
005DC1-Rear Right ABS/DSC Wheel Speed Sensor

I will check tomorrow to see if the codes are immediately back on or if it takes some time. However, it appears that the traction light's illumination served as an alert that something was malfunctioning, rather than the system activating!

What should I look for initially? It seems the speedo won't operate if the rear sensor goes, but I've found that it actually does. Could it be the module, the ABS ring, or the sensor?

[Doncaster34]

Based on the symptoms and code, it seems that the rear right sensor or the reluctor could be the culprit.
With a 99% certainty, Speedo uses data from the rear left sensor.

[Ken_Lion]

What mentioned is something I'll echo.
Putting a washer in the gap between the sensor and the hub is an experiment, but remember that this is just a test.

[Treeri]

Yours faithfully. Another issue with Google is that it also returns AI results, which can indicate that something else is broken or has failed, even though the code for that specific area is different. All the lights seem to be pointing to this, with the exception of the DSC and ABS signals, so I'm crossing my fingers that it's not the module failing. Or am I mistaken? The handbook is also not very useful.

As you sit in the car, is the rear right side the driver's side or the passenger side? It lacks specificity!


How do these sensors often eliminate things? Fifteen years ago, when attempting to remove one from a vehicle, they snapped. Would using brake cleaner and the washer test be beneficial?

Is it probable that these bolts will snap? Should I replace them?

These are a major target for eBay vendors. BMW costs 74p, however they charge a fixed sum of £8 for shipping. I have never seen if the dealer closest to me sells parts, so I will have to investigate that.

[Treeri]

https://www.sytnerstevenagebmwparts.co.uk/p/Bmw__740dX/ISA-screw-M6X16-88-ZNNIV/131952312/07129905536.html

[Treeri]

Is it better to buy a real sensor outright, or are there any less expensive options that still work?

[Treeri]

https://www.sytnerstevenagebmwparts.co.uk/p/132038307/34526752702.html

[Treeri]

I travelled to work this morning after clearing the codes last night. While navigating slightly around a large puddle, the lights remained off for fifteen minutes, at which time the DSC light flashed three times. In an operational state, this is considered typical, as stated in the manual. When I arrived at work, I checked for codes, and everything is still in order. If it's a sensor, do they suddenly stop operating or do they return intermittently? I'm sure they'll return.

[Black_raven]

I assume you mean the right side of the vehicle when you say "drivers side"?

[Treeri]

When traction is being lost, such as on snow, wet roads, gravel, etc., it is typical for the DSC light to flicker. That is not important. The lights remaining on at all times is out of the ordinary; I had a similar experience last year, throughout the winter and rain, after the DSC light started flickering. Similar to what Johnny mentioned, it might be a mechanical problem with the sensor, ring, or sensor wire. However, it could also be the result of a software glitch in the control unit or a computer flaw that prevented the CAN from receiving data. Sometimes, computers do experience issues.

I would assume that this problem rarely happens because of a software bug in a unit connected to the CAN, because your ABS and DCS still function, just like they do on my car, even with the warning lights. 🤷‍♂️


My advice would be to wait it out and not replace anything until you've given it a good inspection. 😉

[Treeri]

You can disable the AI function or just ignore its advice; it's useless. 😉

[Ken_Lion]

All it takes to untie them is a good spritz of penetrating fluid followed by a little twist and pull to the left or right.
Never had an issue with changing bolts, so I'm sure they'll be fine.

[Treeri]

I feel like the DSC light is flashing more often than it should be, as if it were trying to tell me something is wrong.

It wasn't until two weeks ago that the light came on; I've had the car for eight months. Even though there was a cold spell and the roads were icy and frosty. Whenever I drive any of my other cars, the traction light will occasionally come on.


It popped up six times on my six-mile commute to work this morning. Several were moving slowly in a straight line, while others were steered. Last night, things started up again after I struck a daily snag. I drove down the highway for a short distance and everything was OK. It was as expected that the DSC kicked in (I could feel it) and I accelerated when I got off and turned left. At slow speeds, the light doesn't seem to indicate that the system has turned on.

Even though I'm not a fan of Goodyear Eagle F1 tires—they tramline too much—there's a tonne of tread remaining on them. Over the weekend, I will verify the pressures.

Since no codes have been returned, it may be prudent to clean the wheel sensors. I can only assume that they are drenched in filth, what with all the rain that has fallen.

[Doncaster34]

rear nearside, i.e., the passenger side in a right-hand drive vehicle, is where you'll find the sensor that regulates the speedometer, fuel gauge, and other instruments. I had to change mine once after the trifecta lights came up; the process wasn't difficult, but I did need protective eyewear because grit stayed in my eyes for a week.