CAN Bus offline error

[Effduration]

Hi - folks, '06 X5 3.0

Got a check engine light - error was CAN Bus Off-line. The first time it happened, I got a TPMS error as well, but no tires were low on air.

I was able to clear both errors, but the CAN Bus would come back in a day or two.

While the error was clear (no check engine light), I was not able to access either the DSC or the TPMS modules in INPA - no connection to either. But none of the ABS, brake, TPMS error lights are on. No error lights at all.

I read that ABS (DSC) module & Steering angle sensor were on the CAN Bus and if either had a short, the whole CAN Bus would shut down.

I unplugged the ABS module for a few days...I did get a few error codes, but never got the CAN Bus offline code.

Given all this, I am pretty sure my issue is with the ABS Module or or a wheel speed sensors - which also feed signals to TPMS in this car.

My plan is to test my wheel speed sensors with a multi-meter while attached to the car (Can't read live data in INPA) and if they check out, send my ABS module out for a rebuild.

I did do my front brakes about a month before this all started and did replace the brake pad wear sensor on the driver's side front. It is mounted next to the ABS Sensor. I will check that first. My speedometer never stopped working so I don't believe my rear driver's sensor is bad.

Does anybody have any thoughts? Also, can anybody recommend an ABS sensor other than Genuine BMW ? I think OEM Is Siemens, but having trouble finding it for my car.

[PalmSpringsE534.6]

I buy the wear sensors off FCP Euro or off Pelican Parts. . As for the CAN Bus...if you have your ABS unit disconnected and the rest of the CAN Bus (Car Area Network Bus) stays up...then your ABS is on the fritz. As you are aware, they get problematic with age. Mine was causing my transmission to go into Failsafe Mode with an error regarding the output speed sensor at 72 miles per hour although I also had the trifecta of lights. As soon as the rebuilt unit went in, no more issues. I used Module Repair Pro in LA and I'm hAppy. It's quite possible that the communication chip in the ABS is failing which is causing the local network to crash.

[Clavurion]

Was that CAN-bus code only on DME, not other modules? What did you use for diagnostics and did it differentiate more specifics on the code?

Do you actually have tyre pressure monitoring system with sensors or indirect by ABS/DSC module?

[Effduration]

Originally Posted by Clavurion

Was that CAN-bus code only on DME, not other modules? What did you use for diagnostics and did it differentiate more specifics on the code?

Do you actually have tyre pressure monitoring system with sensors or indirect by ABS/DSC module?

Thanks for all responses so far.

The CAN Bus error was on it's own, it wasn't linked to DME or any other module.

I initially diagnosed/cleared it with my trusty bmw-specific Peake R5/fcx code reader (folks don't like these readers but they are my go-to reader) and got Peake error code D8 which is CAN Bus Offline, along with a TPMS fault on dash.

As I mentioned, after I cleared all codes, I was still unable to access, view live data or otherwise see any data in the DSC5.7 or TPMS sections of INPA.

My TPMS system in my '05 E53 is really just a flat tire indicator system using the same ABS sensors to detect different wheel speeds . The earlier US Models had a different TPMS system with pressure sensors in each wheel.

I just bought 2 genuine BMW ABS sensors - one for front, one for rear, thinking it would be good to have spares for the two 15-year old E53's ('05 and '06) i am keeping on the road. It appears the ABS sensors are the same left to right for either the front or rear.