Struggling with intermittent parasitic draw..narrowed down
#11
AudiWorld Member
Thread Starter
Thats the thing. The 12v is never gone not even when car is off and doors are locked. Oh wait! you're saying that it should show 12v when car is off and locked but will show 0 when component is on? can you please confirm that?
I reconnected the tv tuner and disconnected the module besides it (radio module?) and voltage became solid. So I'm thinking now it's not the tv tuner but rather the optic ring remains awake and unless I break it by disconnecting any component within that it will stay awake and drain the battery.
I'll do the ring check on vcds and see if it reveals any issues.
I reconnected the tv tuner and disconnected the module besides it (radio module?) and voltage became solid. So I'm thinking now it's not the tv tuner but rather the optic ring remains awake and unless I break it by disconnecting any component within that it will stay awake and drain the battery.
I'll do the ring check on vcds and see if it reveals any issues.
Last edited by The.aviator2; 10-26-2017 at 08:34 AM.
#12
AudiWorld Super User
Pin 3 is NOT an open diagnostic lead. It is supposed to be connected to the OBD wakeup/sleep lead. This is the white/yellow wire used for the satellite radio as well as other things like the Nav DVD player.. If you want verification, look the the Elsa-Win schematics for the A8.
Cheers,
Louis
#13
AudiWorld Super User
I still don't get it on how you power up the TV tuner
I tested that wakeup sense line (yellow/white) and it's reading 12v all the time. That explains why the tv tuner stays awake. I removed Kufatec harness and problem is still there if I connect the 20-pin connector back on. I traced the sensing wire and it passes through dash panel. If what I'm thinking is right, I'm afraid I read about this problem in another thread in here some time ago.
How could I verify if the sensing line is shorted? Should I try to disconnect it from the data bus J533? That's behind the glove box right?
How could I verify if the sensing line is shorted? Should I try to disconnect it from the data bus J533? That's behind the glove box right?
Cheers,
Louis
#14
AudiWorld Super User
I went to the car at lunch and checked the sense voltage
Opened the trunk, sense line (Yellow/White) = 11.7V
Turn on the engine and the TV tuner on - sense line = 13.4V while black/red power line = 13.6V
Sense line with engine running and TV tuner playing
12V line with engine running
Sense line = 11.73V while 12V = 12.05V
Turn on the engine and the TV tuner on - sense line = 13.4V while black/red power line = 13.6V
Sense line with engine running and TV tuner playing
12V line with engine running
Sense line = 11.73V while 12V = 12.05V
#15
AudiWorld Member
Thread Starter
Hi Louis,
Regarding your question, yes the tv tuner is installed from the factory and the 20-pin connector has only three wires. That's red, brown and white/yellow. I also did the optical ring test and it was good. I tested the sense line and got the same results you're getting. However, when you find the time please try to lock the car open the trunk, close the trunk lock (manually) and see if you still have power in the sense line? In my situation, I have constant power in the white/yellow wire whether car is on, off or locked. I'm still not sure if that's normal.
20-pin tv tuner connector.
Thanks alot,
Regarding your question, yes the tv tuner is installed from the factory and the 20-pin connector has only three wires. That's red, brown and white/yellow. I also did the optical ring test and it was good. I tested the sense line and got the same results you're getting. However, when you find the time please try to lock the car open the trunk, close the trunk lock (manually) and see if you still have power in the sense line? In my situation, I have constant power in the white/yellow wire whether car is on, off or locked. I'm still not sure if that's normal.
20-pin tv tuner connector.
Thanks alot,
#16
AudiWorld Senior Member
I beleive the white yellow is the diagnostic wire for anything on the most loop.
The radio module on some cars was responsible for a current drain but i think it was earlier than the S8 model line.
As a way to determine which module is drawing power you could bypass each module with a most loop adapter, using it you can unplug the tv tuner for example and bypass the fiber connection so the other modules remain working.
The link below is the adapter I'm referring too.
Also are you sure the lights around the gear-stick go off when you lock the car?
FEMALE MOST FIBRE OPTIC LOOP CONNECTOR/TERMINAL For Audi BMW Mercedes Porsche | eBay
The radio module on some cars was responsible for a current drain but i think it was earlier than the S8 model line.
As a way to determine which module is drawing power you could bypass each module with a most loop adapter, using it you can unplug the tv tuner for example and bypass the fiber connection so the other modules remain working.
The link below is the adapter I'm referring too.
Also are you sure the lights around the gear-stick go off when you lock the car?
FEMALE MOST FIBRE OPTIC LOOP CONNECTOR/TERMINAL For Audi BMW Mercedes Porsche | eBay
#17
AudiWorld Senior Member
The white yellow is indeed the OSB wakeup line. The problem with measuring the line is the delay involved. It takes a few minutes for the MMI to shut down the devices. Even opening the trunk or a door will wake up the devices. Try looking at the NAV DVD player lights sometime. The second you open the trunk, the player starts up and the lights begin blinking. Try leaving the trunk open for an hour or so and then measure the wakeup line.
#18
AudiWorld Super User
Let's get back to beginning of time.
1. Since itā€™s a factory unit, it must be connected BEFORE, all the time and it's been great?
2. When did this battery draining problem start?
3. At current condition, does battery drain with
A. Optical plugged with a loop?
B. Power connector unplugged with optical connector plugged in - no loop?
C. Optical plugged with a loop and power connector unplugged ?
We want to make sure the draining is NOT isolated to just TV tuner. I wasn't sure how you tested the optical from the TV tuner.
If you just unplugged the optical and left it opened, then none of the MMI components are turned on.
Iā€™ll check the power today when I get home.
Cheers,
Louis
1. Since itā€™s a factory unit, it must be connected BEFORE, all the time and it's been great?
2. When did this battery draining problem start?
3. At current condition, does battery drain with
A. Optical plugged with a loop?
B. Power connector unplugged with optical connector plugged in - no loop?
C. Optical plugged with a loop and power connector unplugged ?
We want to make sure the draining is NOT isolated to just TV tuner. I wasn't sure how you tested the optical from the TV tuner.
If you just unplugged the optical and left it opened, then none of the MMI components are turned on.
Iā€™ll check the power today when I get home.
Cheers,
Louis
Last edited by ltooz_a6_a8_q7; 10-28-2017 at 09:29 PM.
#19
AudiWorld Member
Thread Starter
....
Also are you sure the lights around the gear-stick go off when you lock the car?
FEMALE MOST FIBRE OPTIC LOOP CONNECTOR/TERMINAL For Audi BMW Mercedes Porsche eBay
Also are you sure the lights around the gear-stick go off when you lock the car?
FEMALE MOST FIBRE OPTIC LOOP CONNECTOR/TERMINAL For Audi BMW Mercedes Porsche eBay
The optical loop idea is great. I will see if I can find one locally to save some time. Thanks.
#20
AudiWorld Member
Thread Starter
The white yellow is indeed the OSB wakeup line. The problem with measuring the line is the delay involved. It takes a few minutes for the MMI to shut down the devices. Even opening the trunk or a door will wake up the devices. Try looking at the NAV DVD player lights sometime. The second you open the trunk, the player starts up and the lights begin blinking. Try leaving the trunk open for an hour or so and then measure the wakeup line.