2013 C7 A6 Allroad 3.0Tdi - Multiple Mulfunction Errors/Messages

[Wudka]

Hi Everyone,

My car has spat the dummy and started throwing up all sorts of errors.

Most frequent are,

- Gearbox Malfunction
- Park brake (With cross through it)
- Air suspension (Ride height stays from what I notice, but ride becomes hard)
- Engine Warning light
- Coil warning light
- Light level malfunction
- TCMS malfunction
- ECS malfunction

THis also leads to the engine loosing power and the car pops out of gear.

I have pulled over, turned the car off and on again and then it has resumed the drive, with either only one or two of the above returning, on occassion, or all returning.

Upon this happening yesterday, I replaced the battery at work, with the hope of clearing the faults, to no result.

Has anyone come across this?

I should note that I was able to drive the car home, with most of the issues dissapearing, however, only the engine light on and a "gearbox malfunction - you can continue to drive the car message.
The car drove under normal power once it got to this stage with no other noticeble issues.

Help would be appreciated.

[Lucas_R]

Hi and welcome to the forum. You need to take you car to a Audi/VW specialist so they can read the fault codes which will give them a pretty good idea to what the issue is. There is no point trying to guess what the fault(s) is. It could be as simply as a loose or damaged earth wire that is causing multiple faults, or you could have a faulty electronic module which is causing the issue etc etc. Needs the fault codes scanned and then a good going over to pin point the issue(s).

While on the topic, I will recommend one of the DIY error code readers to keep in your glovebox. Personally I use Carista, but another popular one is OBD11. Both are heavily developed for VW/Audi cars and are very handy to have. Use it once or twice and it will pay for itself, both in terms of cost and convenience of not having to go to a mechanic.

One off fee for the OBD dongle of $64.95, then its about $80 for a 12 month subscription to the smartphone app.
Carista OBD2 Diagnostic Scanner – Android and iOS | AutoInstruct

OBD11 is a more powerful tool and can do more than Carista, but chances are you will be paying for stuff you wont use/dont know how to use. The cost of this one includes a 12 month subscription: OBDeleven V2 Pro Pack '-' Diagnostic Tool | AutoInstruct

[Wudka]

Thank You Lucas,

OBD scan output below, I am currently defeated -

01 Engine

Trouble codes:

U111300 - Function limitation due to received malfunction value

Intermittent

Date: 2024-01-31 10:03:46

U111300 - Function limitation due to received malfunction value

Intermittent

Date: 2024-01-31 10:03:46

P199E00 - Cylinder head coolant valve Open circuit

static

Date: 2024-01-30 08:23:13

U000100 - High Speed CAN Communication Bus

Intermittent

Date: 2024-01-31 10:05:09

U016400 - Lost Communication With HVAC Control Module

Intermittent

Date: 2024-01-31 10:24:30

U012100 - Lost Communication With Anti-Lock Brake System (ABS) Control Module

Intermittent

Date: 2024-01-31 10:24:18

U021200 - Lost Communication With Steering Column Control Module

Intermittent

Date: 2024-01-31 10:24:25

U015500 - Lost Communication With Instrument Panel Cluster (IPC) Control Module

Intermittent

Date: 2024-01-31 10:20:21

U010100 - Lost Communication with TCM

Intermittent

Date: 2024-01-31 10:24:17

U014600 - Lost Communication With Serial Data Gateway Module "A"

Intermittent

Date: 2024-01-31 10:24:22

U014100 - Lost Communication With Body Control Module "A"

Intermittent

Date: 2024-01-31 10:20:21

02 Transmission

Trouble codes:

P189300 - Signal wire for gear display in selector lever Electrical error

Intermittent

Date: 2024-01-30 08:29:22

P189400 - Signal wire for gear display in selector lever Implausible signal

Intermittent

Date: 2024-01-30 08:20:05

P189200 - Selector lever position detection Faulty

Intermittent

Date: 2024-01-30 08:29:04

P189000 - Signal wire for Tiptronic Electrical error

Intermittent

Date: 2024-01-30 08:55:42

U010000 - Lost Communication with ECM/PCM

Intermittent

U012100 - Lost Communication With Anti-Lock Brake System (ABS) Control Module

Intermittent

Date: 2024-01-31 10:24:25

U015500 - Lost Communication With Instrument Panel Cluster (IPC) Control Module

Intermittent

Date: 2024-01-31 10:05:45

U014600 - Lost Communication With Serial Data Gateway Module "A"

Intermittent

Date: 2024-01-31 10:08:49

U012800 - Lost Communication With Brake System Control Module

Intermittent

U012600 - Lost Communication With Steering Angle Sensor Module

Intermittent

Date: 2024-01-31 10:07:34

U010000 - Lost Communication with ECM/PCM

Intermittent

U014000 - Lost Communication With Body Control Module

Intermittent

Date: 2024-01-31 10:07:34

U016400 - Lost Communication With HVAC Control Module

Intermittent

Date: 2024-01-31 10:05:45

U021200 - Lost Communication With Steering Column Control Module

Intermittent

P17D800 - Torque limitation due to clutch temperature

Intermittent

U040100 - Invalid Data Received From ECM/PCM "A"

Intermittent

Date: 2024-01-31 10:06:11

03 Brakes

Trouble codes:

U111100 - Function limitation due to missing message

Intermittent

Date: 2024-01-31 10:07:36

U111100 - Function limitation due to missing message

Intermittent

Date: 2024-01-31 10:03:47

U111100 - Function limitation due to missing message

Intermittent

Date: 2024-01-31 10:16:03

U111100 - Function limitation due to missing message

Intermittent

Date: 2024-01-31 10:16:03

U111100 - Function limitation due to missing message

Intermittent

Date: 2024-01-31 10:16:03

U111100 - Function limitation due to missing message

Intermittent

Date: 2024-01-31 10:05:10

U111100 - Function limitation due to missing message

Intermittent

Date: 2024-01-31 10:05:51

U111100 - Function limitation due to missing message

Intermittent

Date: 2024-01-31 10:16:03

U111300 - Function limitation due to received malfunction value

Intermittent

Date: 2024-01-31 10:14:28

U000100 - High Speed CAN Communication Bus

Intermittent

Date: 2024-01-31 10:07:36

U111200 - Function limitation due to implausible message

Intermittent

Date: 2024-01-31 10:21:03

U111200 - Function limitation due to implausible message

Intermittent

Date: 2024-01-31 10:21:03

05 Keyless System

Trouble codes:

01330 - Comfort system central control module Please read DTC

Intermittent

08 Air Conditioning

Trouble codes:

U111300 - Function limitation due to received malfunction value

Intermittent

Date: 2024-01-31 10:05:10

U111100 - Function limitation due to missing message

Intermittent

Date: 2024-01-31 10:16:12

09 Central Electrics

Trouble codes:

01314 - Engine control module (ECM) No signal/communication

Intermittent

Date: 2024-01-31 10:05:00

01315 - Transmission control module (TCM) No signal/communication

Intermittent

Date: 2024-01-31 10:07:00

10 Parking Assistance

Trouble codes:

U112100 - Databus missing message

Intermittent

Date: 2024-01-31 10:07:35

U112100 - Databus missing message

Intermittent

Date: 2024-01-31 10:16:11

15 Airbag

Trouble codes:

U112100 - Databus missing message

Intermittent

Date: 2024-01-31 10:20:30

U112100 - Databus missing message

Intermittent

Date: 2024-01-31 10:07:35

U112100 - Databus missing message

Intermittent

Date: 2024-01-31 10:16:21

U112100 - Databus missing message

Intermittent

Date: 2024-01-31 10:07:35

[Lucas_R]

A lot of those "lost communication" errors are likely to be because you have unhooked the battery recently. Any chance you can erase all of those error codes and then see what comes back.

[Wudka]

I only undid battery after these codes - to replace with new battery.

I’d have to scan it again but the car is throwing its tantrum in exactly the same way as it did before this diagnosis and changing the battery.

[Lucas_R]

Where abouts in Sydney are you roughly? There are plenty of good VW/Audi mechanics in Sydney but no good for me to recommend someone in Castle Hill if you live in Ingleburn for example.

[MIG]

Has the car got a 7-Speed S-Tronic?

If so, check out this Wiki page
7-Speed S-Tronic Direct-Shift Gearbox (DSG/0B5) - Ross-Tech Wiki

Quote from it
"Coolant, water ingress and corrosion problems at the 0B5 Mechatronic connector aren't uncommon. When dealing with a TCM that won't communicate at all -or- is packed full of random DTCs such as P1893, P1894, P1892, P1890, U0100, U0146, P2850, U0100, U0212 and U0401 please see this thread:"

[Wudka]

Has the car got a 7-Speed S-Tronic?

If so, check out this Wiki page
7-Speed S-Tronic Direct-Shift Gearbox (DSG/0B5) - Ross-Tech Wiki

Quote from it
"Coolant, water ingress and corrosion problems at the 0B5 Mechatronic connector aren't uncommon. When dealing with a TCM that won't communicate at all -or- is packed full of random DTCs such as P1893, P1894, P1892, P1890, U0100, U0146, P2850, U0100, U0212 and U0401 please see this thread:"

Update.

Seems this was spot on. I started going plug for plug this morning, checking each sensor and connector and this connector was the first that I have found with moisture/corrosion.

I have cleaned it the best that I can and need to figure out how to do a better job of the clean. I have bought contact cleaner and will try and blow it through, grease it up and reassemble.
Might take my dads advice and try and seal up the top the plug too, although access is not great.

Following the initial clean, which was basic for lack of a compressor and tools to get in there, the car is now driving without fault.

I think this should be a prohibitive maintenance check in the schedule. Ridiculous that Audi dont communicate this design fault to customers and fix it.

I want to upload photos for others reference, but for some reason it is not letting me.

[Wudka]

Update.

Seems this was spot on. I started going plug for plug this morning, checking each sensor and connector and this connector was the first that I have found with moisture/corrosion.

I have cleaned it the best that I can and need to figure out how to do a better job of the clean. I have bought contact cleaner and will try and blow it through, grease it up and reassemble.
Might take my dads advice and try and seal up the top the plug too, although access is not great.

Following the initial clean, which was basic for lack of a compressor and tools to get in there, the car is now driving without fault.

I think this should be a prohibitive maintenance check in the schedule. Ridiculous that Audi dont communicate this design fault to customers and fix it.

I want to upload photos for others reference, but for some reason it is not letting me.

Further update,

The gearbox coolant solenoid valve is very much so the culprit here, with the plug to this valve also corroded and wet. As nominated in other threads with this issue, the coolant escapes this valve, follows the cabling down via the loom to the gearbox control module plug and then corrodes that away to the point of a multi thousand dollar repair if you do not get sufficient intermittent issues and investigate in time - In hindsight, my car had shown signs a few months back, nominating gearbox cooling issues, but the message disappeared almost immediately and I didn't think to investigate the wiring, instead looking into finding a good price to change the gearbox oil.

I have spent the weekend looking into this and am confident that Audi know about with what I have been able to uncover, yet they choose to do nothing about it.

I would strongly urge all A6 owners to at least investigate the condition of their solenoid valves and check the gearbox control module plug for signs of moisture. If none, then modify the harness to allow water to drip away(Cut the heat sleeves) and cut a drain hole into the bottom of the gearbox control module plug cover.

This might save you thousands in repairs and could potentially save you from a major accident, for if it fails immediately like mine did, then you might get Tboned etc.

Thank you for helping me!

[Lucas_R]

You have me wanting to check the 8 speed auto in my Audi SQ5 now. No issues with my car but will happily address a potential issue before it arises.