Lane and Parking assist not working

[EdoFede]

Hello everyone.

I am having a problem with my 2016 A6 Avant C7 purchased used at the beginning of the year.

The Lane assist and Parking assist systems have not worked (both) since I got the car.
For both, when activated via the buttons a "system not available" like message appears.
I've done some research online and some are related to a failure on the fron camera.

But these other systems (which should be linked to the front camera too) on the car work perfectly:
- Adaptive Cruise Control
- Matrix headlights
- Night vision camera
- Braking guard
- Optical recognition of speed limits on road signs

I ran a diagnosis via ODIS-S and found this problem (that returns immediately after clearing):

Address: 008E
System name: 8E - Image Processing Control Module
Log versions: UDS/ISOTP (Ereignisse: 1)

- DTC memory entry
Number: U111300: Function limitation due to received malfunction value
Error type 2: active/static
Symptom: 146
Status: 00001001

- Standard ambient conditions:
Priority: 6
Frequency counter: 131
Elimination counter / driving cycle: 131

- Expanded ambient conditions:
Outside temperature: 25.0 °C
Voltage terminal 15: 11.9 V
Control module temperature: 38.0 °C


Has anyone had similar problems and can give me some advice?

Thanks!
Edo

[Audibot]

Can you post the full scan?

Also, have you checked in the MMI Car settings to see they are active?

[Burkeomatic]

Can you post the full scan?

Also, have you checked in the MMI Car settings to see they are active?

My thoughts too, there should be another code that it is related to. Whenever something says "function limitation due to xxxx" it isn't the problem within that particular module, it is the unit it is receiving the info from. It's basically that module saying "I can't do my job if that guy over there doesn't do his"

[Avantly]

Is it just me or does terminal 15 voltage look really low?

How old is the battery in this car?

[Audibot]

My thoughts too, there should be another code that it is related to. Whenever something says "function limitation due to xxxx" it isn't the problem within that particular module, it is the unit it is receiving the info from. It's basically that module saying "I can't do my job if that guy over there doesn't do his"

I was thinking maybe there's something else that looks unrelated.



Is it just me or does terminal 15 voltage look really low?

How old is the battery in this car?

If the car is running, sure. But this is a normal value if the car is off (I have been anywhere from 12.9 down to 11.4). I am willing to bet if I can mine with the car off, it'll be in that range with no detriment.

[Avantly]

I have noticed that the module-measured battery voltage is lower than you'd expect (at least compared to previous generations). It makes me wonder if they were really stingy with the battery cable that runs the length of the vehicle!

Agree that OP definitely needs to show DTC's from all modules.

[EdoFede]

Hi and thanks to everyone for the answers. [:)]

Both systems are active on MMI, sure.
The MMI system was also fully upgraded to MHI2_ER_AU57X_K3663_1 + Maps (both system not working even before)

I also looked for another code on other modules during the diagnosis, but nothing related.
I only found the "fog mode active" on the headlights, but I saw that it was a sporadic event.
There are no other errors related to this.

The voltage is low because I had the car off during the diagnosis and with only a small 5A charge maintainer connected.

Here is the complete scan:
https://dado.pro/share/NO_ORDER_WAUZZZ4G4GN166797_2024-04-20_12-21-07_dprot.htm

(there is an error on an injector that has nothing to do with it because it is due to a slightly disconnected connector that I then fixed).


Thanks!!

[Avantly]

Well that is strange indeed. There are some of us having issues with the camera modules but with different codes and symptoms (With the BGA ball issue, the camera module is completely inoperative).

When I get a communication error in a single module (like this) with no apparent cause, I will usually first suspect that module, its power/ground feed, or the car's battery itself. As others have pointed out, the battery rail voltage seems to run lower in C7 than previous generations - This is probably related to the wiring from the battery compartment to the front of the car, but I am really not sure. It makes me wonder if modules in C7 have under-voltage thresholds which have been proportionally lowered, or if they have similar under-voltage thresholds to the previous generation. If C7 under-voltage thresholds are similar to C6, this would mean that C7 will be more sensitive to an aging battery than C6 is.

Unless you are certain about your battery's condition, I think a load/impedance test of your battery is in order - Just to make certain that you don't have the voltage dropping out under certain conditions due to higher battery ESR or something like that.

If the battery is absolutely not the culprit, maybe something could be wrong with the camera module (like a bad solder joint?) but I would first be checking the power and ground feeds for the camera module just to make sure you don't have a loose ground connection, misbehaving splice in the harness, bad pin on the connector, etc. I would also check the voltages on the CAN bus pins at the camera module to see if they are within expected values.

And FYI for why I say these things: CAN is quite a robust communication bus, however with an unstable power feed, or a poor ground which causes the "ground" that the camera module sees to be higher than chassis ground by some margin, you can see communication breakdown. I see this most often as a ground problem, not a power feed problem. Additionally, if one of the modules on the bus is pulling one or both of the CAN wires in the wrong direction (i.e. outside of nominal voltage range) this can also cause communication breakdown/corrupted messages/etc. In these cases, the camera module may receive a message on the CAN bus and see this message as corrupt when in fact the message is just fine, which would result in the camera module flagging this communication error, but all other modules being happy.

So, just to summarize, I think a good strategy might be:
-Verify 100% that battery is in good shape
-Check CAN_H and CAN_L voltages at camera module (Measure between camera module ground<>camera CAN pins and between main chassis ground<>camera CAN pins, measurements with both grounds should be the same
-Check resistance between camera ground <> a known-good chassis ground
-Check voltage at camera module between camera +12V and camera ground, with module connected and powered (would require back probe of connector) / Alternatively, use a filament type test light to load the +12V & ground pins at camera connector, and measure voltage with this small load connected; Voltage should droop very little with a small load like a filament test light.

[EdoFede]

Thank you very much for your reply and very detailed analysis.

I don't think there is a "global" voltage problem, because normally the undervoltage events remain recorded (and I happened to see them in the diagnosis when I turned on the car after 3 weeks that it was completely stopped).
Normally the voltage is stable, even when I use the start/stop system.

I don't think there are battery problems, because the error also occurs immediately after the DTC reset. The two systems just can't be activated ever.

However I can check if there are voltage differences (or too much resistance) in the ground path of the cameras, as you kindly suggested.

Today I managed to speak to the person who sold me the car and he told me something interesting:
The steering box had been replaced or repaired after an accident....

I don't know if it could have something to do with the problem, but I'm thinking it could be...since the parking assist turns the steering and the lane assist makes it vibrate... (will they use the same motor?)

Non ho però trovato in diagnosi centraline specifiche di controllo e output test per testare quel motore.

Thanks a lot!

[Audibot]

Curious about these communication faults:

Error messages outside of Guided Fault Finding:
Fault: Core.ODS4011E
Text: ODS4011E Internal: The system does not support the coding DN#NA#NA#1713607677146.

Fault: Core.ODS4011E
Text: ODS4011E Internal: The system does not support the coding UP#NA#NA#1713607681013.

Fault: Core.ODS4011E
Text: ODS4011E Internal: The system does not support the coding UP#UP#NA#1713607681013.

Fault: Core.ODS4011E
Text: ODS4011E Internal: The system does not support the coding UP#UP#UP#1713607681013.

Fault: Infrastructure.Vehicle.ODS8002E
Text: ODS8002E Infrastructure.Vehicle (EcuCom): Communication to the control module with control address 0xFFFFFFFF was faulty.

Fault: Infrastructure.Vehicle.ODS8003E
Text: ODS8003E Infrastructure.Vehicle (EcuCom): The operation on the control module with control address 0x0084 was faulty. Error message: Result Of Allocation List Contains Errors

Fault: Core.ODS4011E
Text: ODS4011E Internal: The system does not support the coding DN#NA#NA#1713607724736.

Fault: Infrastructure.Vehicle.ODS8002E
Text: ODS8002E Infrastructure.Vehicle (EcuCom): Communication to the control module with control address 0x00C0 was faulty.

Fault: Infrastructure.Vehicle.ODS8002E
Text: ODS8002E Infrastructure.Vehicle (EcuCom): Communication to the control module with control address 0x0002 was faulty.

Fault: Core.ODS4011E
Text: ODS4011E Internal: The system does not support the coding UP#NA#NA#1713607736392.

Fault: Core.ODS4011E
Text: ODS4011E Internal: The system does not support the coding UP#UP#NA#1713607736393.

Fault: Core.ODS4011E
Text: ODS4011E Internal: The system does not support the coding UP#UP#UP#1713607736393.

Fault: Core.ODS4010E
Text: ODS4010E Internal: The data structure 0#334296#0#0#JE2:5HDHYC3122632A11132#67958#1713607 759354#1713607864543#T0TY2192932JVQSEBUFOFSGBTTVOH A11111#0#0#0#T0T5H21:2332IBVQUQSPHSBNNTUBSUNPEVMA1 1132#23477#1713607865026#1713607874012#T0TY1:2932W FSLPLVOHTFLVOEBFSMVGUEJBHOPTFEBUFOFSGBTTVOHA11111# 0#0#0# contains content errors.

Fault: Infrastructure.Vehicle.ODS8020E
Text: ODS8020E Infrastructure.Vehicle (EcuCom): An error occurred during communication with the vehicle: The operation on the control module was faulty.

Fault: Core.ODS4010E
Text: ODS4010E Internal: The data structure 0#362673#0#0#JE2:5HDHYC3122632A11132#67958#1713607 759354#1713607864543#T0TY2192932JVQSEBUFOFSGBTTVOH A11111#0#0#0#T0T5H21:2332IBVQUQSPHSBNNTUBSUNPEVMA1 1132#23477#1713607865026#1713607874012#T0TY1:2932W FSLPLVOHTFLVOEBFSMVGUEJBHOPTFEBUFOFSGBTTVOHA11111# 0#0#0#T0T342212932SFBEJOFTTSEXA11132#51771#1713608 423268#1713608436039#T0T5H21:2332IBVQUQSPHSBNNFOEF NPEVMA11132#7799#1713608437278#1713608445077# contains content errors.


Also based on what you just said, I would recommend a steering calibration/adaptation. Usually the steering angle sensor will throw a code but I do not see that. It's possible you need Audi or a shop to do the sensor calibration but I really hope not.

[Avantly]

Very interesting! I suspect this could be related!!! I am not familiar with C7 steering rack coding, but I believe there are quite a few coding options for the rack and ABS unit as related to the suspension, differential, and more. It doesn't explain why the camera would claim a communication error, but maybe the camera is just seeing a message from a desired address (rack or ABS) that it doesn't understand due to incorrect coding? I would hope that the rack was replaced with one of the correct hardware and software revision - It seems that you would have other problems if it were not.

[EdoFede]

Hi all,
I did some research based on what you reported.

I went under the car and checked the code of the installed steering box: 4G1423055EC with control module 4G0909144T.
Checking on ETKA, it seems OK (the 4G1423055EC is the latest version released in 2021 that replaces the previous one).
So the installed steering box, which has been replaced, seems OK.

The control module responds to address 0044 in the diagnosis and has these codings:


Index Byte Value (hex) Value (bin)
1 $1 $01 00000001
2 $2 $00 00000000
3 $3 $00 00000000
4 $4 $00 00000000
5 $5 $00 00000000
6 $6 $00 00000000


I obviously have no idea if they are correct (I haven't found any info online).
However, the module does not report any errors.

I will have to try to recalibrate the steering angle sensor as you suggested and see what happens...

Regarding the error outside te guided fault finding, I noticed them (much more numerous) in a previous diagnostic log.
Could it be a problem with the VAS 6154A (VNCI) interface I use?

Thanks a lot,
Edo

[Avantly]

Unfortunately I use VCDS most of the time and I am not familiar with coding using ODIS; I am also not familiar with coding values for these racks. I do know that on the VCDS forums it has been determined that generally speaking, when replacing the rack and module, the new module should be coded the same as the old module.

[EdoFede]

Unfortunately the steering box change was done by the previous owner and I have no idea if it was done by an Audi workshop or a generic mechanic.

I will look for some information on the coding of this module.

Thanks

[EdoFede]

Searching a bit online, I found some coding (also for other car models) of the same control module and I noticed that they are all extremely different from the coding that is on mine.
(it doesn't mean much, I know... but the coding of my control module is the only one extremely different from all those found online)

Examples:
https://vagcode.info/components/3a65a2b6d07f1f93ca204b391f9d354a.html
(101001010001)

https://vagcode.info/components/c1be4b2ca4f3037ffa40e07fcdd22e18.html
(101000010000)

https://vagcode.info/components/1bf4f03e4e418bbf89632f335944aa14.html
(101000010000)

https://www.audiworld.com/forums/a6-c7-platform-discussion-194/no-power-steering-issue-steering-defective-headlight-range-control-tpms-3055721/
(101000010001)

Starting to think that this could actually be the problem...
As soon as I have some time, I'll connect again with ODIS and see if I can find some indication on the coding bits.

[Avantly]

I see similar results on Ross-tech - Yours only has a single bit set to '1' but on the rack codings shown on their site there are always at least a few bits set to 1.

I saw a reference on ross-tech regarding "online coding" done by the dealer - I couldn't find more info on this - I suspect it might be similar to other manufacturers (i.e. loading "as-built" data that corresponds to VIN on a Ford ABS or power steering rack via Motorcraft FJDS software + subscription) and maybe this is possible with an ODIS online subscription? It would be interesting to find out. I think this must be mentioned in the workshop manual for steering rack replacement? I don't have ELSAwin in front of me right now.

[EdoFede]

Are you referring too this wiki?
http://wiki.ross-tech.com/wiki/index.php/Audi_RCEPS_Steering_Assist

I'll take a look at Elsawin for the replacing procedure. Thanks!

I used to use VCDS in the past (much simpler), but I got scammed with a used fake interface (upgrading to HEX-V2), so I ended up going with VNCI and using ODIS.
Maybe it was a mistake, but the cost of the new VCDS interface is really too high for the use I'm going to make of it.

[EdoFede]

I am very happy to report that I managed to solve the problem!! [:D]

As emerged during the analysis and with your help, the coding of the control module on the (replaced) steering box was wrong.

I had a bit of trouble finding the correct coding (also because the "official" ODIS-S software itself does not have all the coding bits documented [headbang]), but by cross-referencing some data, I managed to find the correct coding for my module 44.
Old coding: 01000000000
New coding: 011101000000

This thread was very helpful:
https://www.audiworld.com/forums/a6-c7-platform-discussion-194/a6-active-lane-assist-retrofit-2890924/

Thanks to everyone for the support! [;)][:)]

[Audibot]

Congrats OP!

[Avantly]

Excellent work sir! This is very good information for people who have similar problems in the future! It's very interesting that this "received malfunction value" code in the camera module actually seems to mean "that darn gearbox is confused about its identity" xD

[EdoFede]

Thanks for your help! [:)]


It's very interesting that this "received malfunction value" code in the camera module actually seems to mean "that darn gearbox is confused about its identity" xD

[:D][:D]

[Avantly]

You are welcome, I am glad you were able to get it working. I wonder what the dealer would have charged for this - I think you've probably paid for a good portion of your VNCI tool with this repair :-)

[EdoFede]

Of course, yes. It's already paid off. [:D]