Battery woes, related "ghost" ABS/DSC faults and fix!

[cmichaelo]

Over the last two years, ever since I installed the Voltphreaks VPM1200 LiIon battery (9lbs vs stocks 60lbs), I have occasionally encountered the following faults (Carly codes):

5D93 - DSC controller valve relay: Medium or high-resistance short circuit of voltage supply_FR or valve after ground registered through start-up test
5E49 - Wheel speed sensor rear right: Missing impulse ring wheel RR - proof good test required!

I've encountered these codes several times and they come and go but may stay on until some random time they just go away again. At first I had "a little help" from a repair shop but they didn't explain well the root cause of the above faults but instead "fixed" another related problem and somehow that resolved the above issues as well. I was always sceptical about what they actually fixed. Now I suspect they did some post-ECU/OBD2 resetting I wasn't able or knowledgable to do myself.

Since then I've heard from several people that poor battery or charging issues can cause these kinds of faults. Now that makes a lot of sense in my case because the VP battery does not like being charged below 13V for too long or it will start behaving weird. And <13V charging can happen if idling for too long on a hott day.

Anyway, apparently, according to this post, there's a simple solution to the problem.

The issue is that, paraphrasing from above link:

"The calibration of the steering angle sensor can be lost at low battery voltages"

and to recalibrate it:

"Start the car and while parked, turn the wheel all the way to the left, and then all the way to the right. This should calibrate the steering angle sensor."

So I did this, well actually, I drove it around my parking lot turning the steering wheel repeatedly all the way to the left and then right. And BAM, the code went away.

Hope this is useful to all.