There is not a lot of discussion about the SBC brake units on 05 and 06 CDIs, and I recently had issued with mine, so I'll update the group with what happened.

I was out on a test drive (for a fuel issue I was chasing), I inadvertently hit a hard pothole, and heard an excessively loud clunk in the front right suspension. It drove OK immediately after, so I wasn't overly concerned.

About a mile later, under normal driving conditions, I got the red dash of death...more specifically "Reduced braking power...stop immediately" etc. The braking power was very severely reduced...step hard on the pedal, and the car slows down gradually. I'd bee in dire straits if I needed a panic stop.

I was about 5 miles from home, and decided not to stop (pardon the irony) and continue to get the car back to my home to assess the situation. The drive home consisted of loud beeping, changing panic info on dash, and car would not shift beyond 2nd gear.

At home I disconnected the SBC connector and reconnected, and red dash went away, and brakes felt normal.

I assumed since the red dash came on once, it will come on again, and severely reduced braking power is unsettling.

I ordered SBC unit from online MB (about $980 but $150 core charge, so net of $830). There are at least 4 different SBC units (for different platforms) so I needed to supply my VIN for the correct one. What I didn't know it that it also needs programming after installation.

I installed the unit, bled the calipers using the Motive Power Bleeder (model 0109 is the right one for the CDI). First time using that power bleeder, and it's awesome.

Without programming though, you get nothing. Red light immediately, and it will let you start the car, but not move it out of Park, so I can't even have it towed to someone to have it programmed.

I end up putting the old unit back in, bleed the lines again, and hope for no red dash. No red dash, and drove cautiously to a local indy that has MB programming tools. They installed new unit, bled and programmed it ($527 later) I'm good to go.

What I learned is that the SBC is truly brake by wire...under normal operation you are using none of your foot to move hydraulic fluid to a caliper. Sensors measuring brake pedal application position and rate is what is telling the SBC unit to send fluid and at what pressure to which wheels. The master cylinder is only emergency (and doesn't do a very good job of it).

I also learned if your car doesn't want to move, it will not let you go out of park, no matter what you try!

I do all my own work, so It's frustrating being at the mercy of others since I don't have the $40,000 programming equipment.

And I have no idea if the hard pothole contributed to the SBC unit failing of not, just a data point I have.

...but I still love my CDI

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Mark in MA
05 MB E320CDI 402k Granite Grey Metallic
05 MB E320CDI 267k Black
05 MB E320CDI 232k White
05 MB E320CDI 209k Tectite Grey
99 Dodge 2500 Cummins 5sp 148k
62 Jeep CJ-6 120k