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Fault Code Deciphering After Modifications

krs

Drag Racing Champion
Location
Idaho
Car(s)
MKVIIS R
Mainly I need to post here for any perspective on checking these boxes off for corrections, but I also need a place to keep my thoughts as I work through this as well.

For the past few weeks I've been doing some work on the car. This started as a new suspension and bushing project, which turned into a RMS replacement and clutch. The one thing I neglected to do was to measure the before ride height on the EMD springs, to try and get to a similar height with the coilovers. But really, I wanted a little higher height than what they offered anyways.

I put new Bilstein DCC coilovers on, offset bushings on the front LCA's, and bushing in the rear trailing arms. The subframe was pulled, and then transmission for the clutch. The steering rack was left in the car, attached to the hubs, and secured from dangling during everything else. The battery was left on a tender for the duration in order to maintain it's charge. I rechecked all the plugs aside from those in the wheel wells to ensure nothing was missed, and nothing was.

Here's the list of current fault codes:

OBDeleven vehicle history log
Date: 2022-01-12 16:31:37

---------------------------------------------------------------
Full scan
Control Units: 28
Fault count: 9
Control Units:

01 Engine
System description: 2.0l R4 TFSI
Software number: 8V09C0BB01
Software version: 0001
Hardware number: 06K907425E
Hardware version: H13

Faults:
17178 -
static


A5 Driver Assistance
System description: MQB_B_MFK
Software number: 3Q0980654H
Software version: 0272
Hardware number: 3Q0980654A
Hardware version: H08
Serial number: 02081712K10225

Faults:
U112300 - Databus error value received
static


03 Brakes
System description: ESC
Software number: 5Q0614517CE
Software version: 0413
Hardware number: 5Q0614517AC
Hardware version: H25
Serial number: 52007000002266

Faults:
B116829 - Steering angle sensor
Implausible signal
Intermittent


B116829 - Steering angle sensor
Implausible signal
static


76 Parking Assistant
System description: PDC 8 Kanal
Software number: 5QA919294B
Software version: 0044
Hardware number: 5QA919294
Hardware version: H07
Serial number: 00030841861721714680

Faults:
U112300 - Databus error value received
static


13 Adaptive Cruise Control
System description: ACC BOSCH MQB
Software number: 5Q0907572J
Software version: 0654
Hardware number: 3QF907572
Hardware version: H10

Faults:
C110300 - Adaptive cruise control sensor
misadjusted
static


U112300 - Databus error value received
static


U112300 - Databus error value received
static


U112300 - Databus error value received
static


The engine code is the O2 sensor, guess I'm not sure which one, but if I remember right this is always present with the Stage 2 tune.
My thoughts are most of these are connected, not a matter of multiple issues, kind of. I'm thinking there might be something with the one of the front wheel sensors, maybe with all the fighting on getting the damn hub to slide onto the new strut body. Even with the axle out, this was a royal hassle. I did some real time monitoring though, and each sensor was reading speed, although the fronts had errors on the air gap section. Not sure what that means.


  • The ACC I'm sure is due to the ride height being different that it was before.
  • The parking assist error I'm guessing is tied to the brake errors.
  • The brake errors are saying steering angle sensor, so I'm guessing because the rack was touched, and the steering wheel is a little crooked now, that has something to do with that.
  • The driver assistance error I'm sure is connected to everything, because it needs all the inputs for the corner lights, the braking, all the other features.
  • I'm guessing the traction control light, ESC light is tied with the wheel sensors?
One thing that was a pain was trying to equalize the rear offset bushing for the front control arm. The adjustable camber bushing was the same, but this one can be fine tuned on the alignment rack.

Here's my plan of attack in order listed.
  1. Check the front wheel sensors, and their connections, and essential any electrical connector within the wheel wells.
  2. Work on leveling the ride height first. I'm not sure there's anywhere in East Idaho to do corner balancing, and I really never thought of that much as it's a daily, with autocross duties.
    1. With the ride height set, then I can work on the ACC alignment.​
  3. I have the alignment scheduled for Friday, once that is done then I can work on the steering angle calibration.
    1. Hopefully I didn't jack the rack up some how to where it's damaged. All the plugs are intact and connected. I never touched them.​
  4. All those dumb Databus errors.... No clue. Hopefully the big issues being read clear them up.
Thoughts?
 
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Cuzoe

Autocross Champion
Location
Los Angeles
Have you cleared faults and drove the car a few yards? You can also start the car and turn the steering wheel lock to lock, which will probably clear most of those. Databus missing messages just mean one module wasn't able to talk to another module that it knows (from coding) should be there. If the communication is one way you'll see the fault on the "receiving" module, otherwise expect to see the message on at least two modules. A lot of these look like faults from having batteries disconnected.

As you suspect, the ABS/brake errors are the cause of most of these. ABS faults will take down ACC as well, it needs them to keep your distance. I would not typically expect ACC faults due to a ride height change. I see it says misadjusted, but that may clear when you get everything cleared. If I sit in the garage too long with the door closed, ignition on, I start getting ACC faults. Doesn't seem to like bouncing off the doors/walls for a length of time. They clear when I start driving.
 
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The Fed

Old Guys Rule
Location
Florida
Did you put the car to sleep before you started? At the least, it sounds like the ECM was awake when you unplugged the sensors. Unless someone has a better idea, get the car aligned then clear any codes.
 
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The Fed

Old Guys Rule
Location
Florida
Have you cleared faults and drove the car a few yards? You can also start the car and turn the steering wheel lock to lock, which will probably clear most of those. Databus missing messages just mean one module wasn't able to talk to another module that it knows (from coding) should be there. If the communication is one way you'll see the fault on the "receiving" module, otherwise expect to see the message on at least two modules. A lot of these look like faults from having batteries disconnected.

As you suspect, the ABS/brake errors are the cause of most of these. ABS faults will take down ACC as well, it needs them to keep your distance. I would not typically expect ACC faults due to a ride height change. I see it says misadjusted, but that may clear when you get everything cleared. If I sit in the garage too long with the door closed, ignition on, I start getting ACC faults. Doesn't seem to like bouncing off the doors/walls for a length of time. They clear when I start driving.
Most every time (I'll have to check now) I start my car I get a momentary ACC error.
 
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Cuzoe

Autocross Champion
Location
Los Angeles
Do a DCC calibration after you get your alignment done and height set (or corner balancing done). It will require the car off the ground with all four wheels hanging, but only takes a second to do.
 
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krs

Drag Racing Champion
Location
Idaho
Car(s)
MKVIIS R
Have you cleared faults and drove the car a few yards? You can also start the car and turn the steering wheel lock to lock, which will probably clear most of those. Databus missing messages just mean one module wasn't able to talk to another module that it knows (from coding) should be there. If the communication is one way you'll see the fault on the "receiving" module, otherwise expect to see the message on at least two modules. A lot of these look like faults from having batteries disconnected.

As you suspect, the ABS/brake errors are the cause of most of these. ABS faults will take down ACC as well, it needs them to keep your distance. I would not typically expect ACC faults due to a ride height change. I see it says misadjusted, but that may clear when you get everything cleared. If I sit in the garage too long with the door closed, ignition on, I start getting ACC faults. Doesn't seem to like bouncing off the doors/walls for a length of time. They clear when I start driving.

Yeah I forgot to add that. I've put a normal amount of miles on the car from past experience that should have cleared everything. Good to know the databus messages, and what they indirectly mean.
 

krs

Drag Racing Champion
Location
Idaho
Car(s)
MKVIIS R
Did you put the car to sleep before you started? At the least, it sounds like the ECM was awake when you unplugged the sensors. Unless someone has a better idea, get the car aligned then clear any codes.

Uhh... nope 😳

In all my searching I never saw anything that said to do something like this. Parked the car, then the next day started the process for removing the transmission, which included pulling the battery out first.
 

Cuzoe

Autocross Champion
Location
Los Angeles
If the car is parked and locked it will go to sleep after some amount of time, I don't know the exact number but it seems to be around 15 minutes. If the battery was disconnected then the car being *awake" is not likely your problem.

Driving will typically clear the ABS related faults that pop up if the car is awake while something is disconnected. But you should still manually clear all faults OBDEleven or VCDS and then see what remains. Anything that actually has a fault will just come right back but other faults won't ever clear on their own even if they are no longer active.

As an aside, later versions of VCDS or ODIS will Tell you exactly what the data bus error is... Like from which module it should be coming from and on which can bus (convenience, drivetrain, extended, suspension, etc.). Some interfaces don't support the full length of the data bus fault messages (so they look generic) but they are really descriptive and make troubleshooting easy.
 
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krs

Drag Racing Champion
Location
Idaho
Car(s)
MKVIIS R
Had my alignment done today, everything was so off, as is expected with pulling the subframe.

Prior I went through and checked all the speed sensors, wiring, etc and found nothing out of place. I figured I’d wait until the alignment, then work back.

Anyways did the steering rack calibration procedure, and it seemed to clear everting up for now. I put about 25 miles on of varied driving, and the only fault still present is the ACC misaligned. When I tried to recalibrate it it, it shows an error was detected, and I can’t clear the code. I’m wondering if I bumped something, so will maybe dive into that this weekend.

I have an appt Monday at the dealer to start the water pump warranty discussions, maybe I’ll see what they say about the ACC sensor.

I also followed the procedure for the DCC calibration. Pretty simple process, guess I just “hope” it worked.
 

krs

Drag Racing Champion
Location
Idaho
Car(s)
MKVIIS R
I had the car into the dealer today for the classic, minor coolant smell and leak concerns. I talked to the tech, he can’t find anything even after pressuring the system at 1.5 bar for a few minutes. Oh well, at least the concern has been documented.

As for the ACC, they wouldn’t even entertain it under warranty, which I understand and wasn’t really implying it either. I guess with me raising the car over the EMD springs, makes sense for it to not be aligned anymore.

Either way, it’s squared away for now.

C99C1F76-0339-4A6D-A9E4-5EE5F00C4C4D.jpeg


The tech did give great compliments on how the car is setup, guess that’s makes me feel like it’s not a full hack job.
 
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