ASC and other problems when the Z3 hits a bump -- help

[sjfuqua]

First post.
Recently obtained a 2000 BMW Z3 2.8. First 800 miles no issues.
Only significant recent work has been to replace front control arms and bushings due to worn ball joints.
After the work, began noticing issues (maybe related or unrelated to the work I did).
When driving at speed, if I hit a bump that jars the Z3, I get an EML light (sometimes), ABS light (sometimes), and ASC indicator light (sometimes). They all eventually clear on their own.
Sometimes when the happens, the car runs rough for a minute, and then corrects.
And once, it appeared the instrument cluster rebooted (all lights came on for a second like when you first turn on the ignition).

I have used Tool32 to calibrate the steering angle sensor after the suspension work (for good measure).

I have run INPA and get two errors (see attached) (Chassis/DSC module).

Any suggestions where I should began troubleshooting (hoping the first thing is not to replace the steering angle sensor)?

Steve
2000 BMW Z3 2.8

Thank you.DSC Stored Errors 23Nov18.JPG

[Muzz258]

The fault happens when you hit a bump, so sounds like something is loose. Start looking for a loose connector related to the steering angle sensor.

[Randy Forbes]

Also, check the ground cable at to top/rear of the RH shock tower. DME ground attaches there, and can wreak all sorts of mysterious faults.

I've seen it a few times, and have heard stories of others, so it's nearly a thing.

EDIT: when I say check the ground, what I'm really saying is take it apart, clean all contact surfaces with a s/s toothbrush, and a dab of Kopr-Shield upon reassembly. Tighten securely, but don't bust anything.

[sjfuqua]

Thank you for the tips. Will check the ground connect and the SAS connections and see what happens.

[sjfuqua]

Hi Randy
Can you vector me in—-do I look from within the wheel well or from the engine compartment to find the ground wire location? Any other locating clues? Thank you.
Steve

[fallguy]

Don’t know if it acts up on bumps when this problem occurs.....

http://funthrulens.blogspot.com/2018...n-bwm.html?m=1

[Randy Forbes]

Hi Randy
Can you vector me in—-do I look from within the wheel well or from the engine compartment to find the ground wire location? Any other locating clues? Thank you.
Steve

Engine compartment, top-rear of RH strut-tower.

The stud in the ten o'clock (10:00) position in the picture.



Also seen here @ approximately the 7:30 position:

[sjfuqua]

Thanks for the assist. Ordered the Kopr-shield and will give this a try and report back. Steve

[sjfuqua]

Update. The problem has been fixed.
First -- I cleaned the DME ground as suggested by Randy.
Second -- while checking grounds decided to clean and tighten the battery connections. While cleaning the positive terminal post found that that one of the positive leads had pulled out of the lug and was just touching (a very poor crimp). Cut back the insulation and recrimped for a good fit. See attached.
Test drive SAT. Not sure if one or both was at the culprit but suspect it was the loose positive lug at the battery.