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Hi guys have a problem with my audi a4 2012 mmi 3g basic screen load after audi logo then go black no light on central panel have plug in to computer and find this error anyone be able to help?
It goes out because there's a break on the optical bus, as noted by the 00384. Could be a physical break in the line, or one of the devices is bad. Each device on the loop has to pass the signal along the loop.
You also have problems with the LIN bus line that connects the J533 to the voltage regulator on the alternator and the BEM on the battery negative post. Could be a physical wire issue (they all use the same wire) or one of the devices is trashing the LIN bus on that line. That has nothing to do with your MOST infotainment bus (the optical bus) issue.
It goes out because there's a break on the optical bus, as noted by the 00384. Could be a physical break in the line, or one of the devices is bad. Each device on the loop has to pass the signal along the loop.
You also have problems with the LIN bus line that connects the J533 to the voltage regulator on the alternator and the BEM on the battery negative post. Could be a physical wire issue (they all use the same wire) or one of the devices is trashing the LIN bus on that line. That has nothing to do with your MOST infotainment bus (the optical bus) issue.
OK thanks for your answer I'm completely newbie but from my understanding what I need to do is check each module to find what one coasing a issue and check for fuses are no out? If they be OK that's mean it would be a physical break on optical cable? Also I have find some topic that if battery voltage is below certain level that's what happens with mmi system u think this could be a issue? As searching for break in optical cable be pretty difficult i can imagine
Do the optical bus diagnostics in the VCDS applications, see what it has to advise regarding the state of the optical bus. As for device presence, did an autoscan show any devices as not reachable?
Do you have a low battery voltage? What is term 30 and term 15 reporting as in block 1 of address 19 (J533 / CAN Gateway)?
Maybe start with a full autoscan and save that to a log file and post the log file contents here in a quote block ([ then the word QUOTE then ] , after the text, do the same thing but with /QUOTE in the square brackets).
I have make this test and shows this
Baterry voltage when car no running was 12.30v so I think is quite low but no sure below I attach log from full scan there is few faults bo have no idea what they mean tbh
12.3v is fine. The battery at max voltage with the alternator off would be 12.7v or so. It's the alternator running that drives the voltage up into the 13v and 14v ranges.
J500 (addr 44) electric steering rack control module - that's a B8.5 thing; my B8.0 has the hydraulic steering. So not sure what to make of that. The error says the rack isn't seeing power, but I imagine that would be obvious to you if that was the case. Maybe clear the codes in that module, see if they come back.
J393 (addr 46) central convenience control module - fuel tank door lock actuator, common problem, replace the actuator to solve it.
So why does the scan from the 19th not attempt to talk to media player 1 at addr 0E or the digital radio at addr 0F? Are you messing around with the installed equipment in the vehicle, or messing with the installed devices list in the CAN gateway?
Why do your scans say 5F cannot be reached, but the optical test you just showed shows the J794 responding on electrical and optical?
The MMI system for 3G stopped using the high and low and basic terms. There's MMI Navigation (which would be the "Low") and MMI Navigation plus (which would be the "High").
Apparently, the CD changer, AMI, and digital radio are options in a MMI Navigation system. Do you have the AMI port or the CD changer in the glove box?
Curious that the digital radio would show up as an address since there's no separate tuner for digital radio in MMI 3G; that would be a 2G thing. Thus it's like someone is going around flipping bits incorrectly.
12.3v is fine. The battery at max voltage with the alternator off would be 12.7v or so. It's the alternator running that drives the voltage up into the 13v and 14v ranges.
J500 (addr 44) electric steering rack control module - that's a B8.5 thing; my B8.0 has the hydraulic steering. So not sure what to make of that. The error says the rack isn't seeing power, but I imagine that would be obvious to you if that was the case. Maybe clear the codes in that module, see if they come back.
J393 (addr 46) central convenience control module - fuel tank door lock actuator, common problem, replace the actuator to solve it.
So why does the scan from the 19th not attempt to talk to media player 1 at addr 0E or the digital radio at addr 0F? Are you messing around with the installed equipment in the vehicle, or messing with the installed devices list in the CAN gateway?
Why do your scans say 5F cannot be reached, but the optical test you just showed shows the J794 responding on electrical and optical?
The MMI system for 3G stopped using the high and low and basic terms. There's MMI Navigation (which would be the "Low") and MMI Navigation plus (which would be the "High").
Apparently, the CD changer, AMI, and digital radio are options in a MMI Navigation system. Do you have the AMI port or the CD changer in the glove box?
Curious that the digital radio would show up as an address since there's no separate tuner for digital radio in MMI 3G; that would be a 2G thing. Thus it's like someone is going around flipping bits incorrectly.
So that's mean battery is not a issue here then which is good.
Yeah I no see or feel any issues with steering so maybe is old fault and no one clear and I own car just for couple months,
I have no idea why is like this as I have no knowledge at all all what been done about week ago was software update and maps and for whole week no issues at all so no sure if updating system in this case would be a issue? Don't have Cd changer in glove box but there is a ami port and cables also quite confident I have digital radio too
You might look for someone you know that is comfortable with electronics and circuits and analytical troubleshooting who can get hands on with it. It's very inconsistent in the logs, which will be an endless problem.
There's a lot of quick checks that need to happen hands on to get a sense of what's actually present and not, but trying to explain all that out remotely, ....
With devices on the optical bus offline (in this case, the radio, at a minimum) that'll break the bus. The normal sequence here would be to use a bypass loop. You unplug the optical plug from the device, such as the radio unit in the left rear, and put the bypass loop on the plug (not on the device, on the cable, so you need a bypass loop with a female plug). If the loop comes up, that device was the break in the chain. Usually because something about the device has broke. In this case, the car cannot even talk to the radio electrically (via CAN bus).
You're going to want to look into that LIN bus issue for the battery management too. That'll become a problem for the battery in the long term if not corrected. Could be a bad voltage regulator, or the wrong voltage regulator (should only be a 1 pin, and the one from the B7 years might look similar but it's not the same), or likely a line issue.
09-20-2020, 09:57 PM
Mmi 3g basic problem
