4.6is - DSC Trifecta ONLY when Traction Control is trying to kick in; ABS normal
 

Hey guys.
Really liking this forum so far. Have found a lot of useful information since I joined.
I believe this is my first post though, and I would definitely appreciate any help with my issue.

First and foremost, I have been battling the ABS/DSC/Brake light issue on my 02 4.6is for a couple months already. I have spent countless hours on searching various threads/posts about the various problems/solutions but I have not found anything quite like mine.

It all started with all three lights coming on one day when I was cruising on the highway this past summer. My display also popped up a "trans failsafe". I started doing some research, checked codes with DIS, and found out that my ABS/DSC module was at fault (no communication whatsoever with the DSC module). I sent it in for a rebuild.

Got the module back, reinstalled it, and everything seemed fine. Until one day, I had to take a quick left turn from standstill. It felt like the left rear tire broke loose a little and I got all three lights on the dash immediately.
Got home, shut it down, restarted and all lights are off. Went for a drive, got it up to 75mph...no problems. Hit the brakes pretty hard, and ABS kicked in so I know it was working.
Got back home, pulled the codes with DIS and got a few different ones:
Front right wheel sensor
Rotational Rate sensor
51 DSC Pressure sensor, line (I assume this is the brake pressure sensor)

So far, I have replaced the wheel sensor and the rotational rate (yaw) sensor. Those codes no longer come up after clearing everything, but the same issue continues.
Now that we got some snow on the ground, it happens a few times a day. Each time, ONLY when I lose traction on snow/ice and the traction control is trying to activate.
If I shut it down and restart, all lights are gone and ABS functions normally. But as soon as any tire loses traction and DSC is trying to correct, the lights come on and my DSC and ABS no longer function, until I restart the car.

The only codes I get now (after clearing a few times) are:

DSC 5.7 - 51 DSC: Pressure sensor, line - DSC actively switched - no ABS control - Brake-light switch: not actuated-
Pressure sensor B3450_57051

&

INSTRUMENT - BD IKE: Electronic braking-force distribution
Instrument cluster (IKE High) kom



What could this be? Brake pressure sensor? Pre-charge pump? Or something else?

Any thoughts or ideas would be appreciated.
Thanks.

Don't worry about the Brake force distribution code, its a glitch and all E53's will throw it.

Is there a DSC pressure sensor test plan?

Oh ok. Good to know.

Yep, I went through the test plan...which basically is checking the pressure with the pedal not pressed. Its at 0...sometimes jumps to 1.

And who did your rebuild of the module?

I wouldn't want to throw parts of it but I've heard the brake-light switch could be sticking, causing the fault.

BBA did my rebuild.

Do you mean the switch on the brake pedal itself?

Yeah, I've heard the switch by the pedal has gone over many revisions over the years, worth looking into. Or the DSC pressure switch itself:

Search SiteSearch 34511165467 - 34511165467 - DSC Pressure Sensor - ES#62814

Any chance it might be the pre-charge pump? I'd hate to just start throwing parts at it and seeing what sticks. Hoping to cross off at least one item off the board.

No clue how to test that. I'm due to send my module in for a rebuild myself, glad to hear you were pleased with BBA

Ok. Well thanks for the response. I appreciate it. Hopefully, someone that's had a similar issue can chime in. Those lights popping up everyday are really getting annoying.

Anyone else willing to lend their .02? Looking for all the info and/or opinions I can get