Real time help, stuck at work.
12-10-2016, 06:34 AM
#112
AudiWorld Member
Thread Starter
I'm a little worried that I haven't actually fixed anything. Jumping those terminals gave power to something, but I don't know enough about it to understand how it's starting now. I have two VW relays on order, so at least I will have good relays in there after Tuesday, until then I'm carrying a small tool kit in the rear footwell to strip the dash down and jumper those terminals again....
12-10-2016, 06:42 PM
#113
Jumping 30 to 15 @ relay J329 effectively duplicates a successful request to start from the module J518.
So I have two theories here :
1. Running current through the circuits and/or mechanical disturbance has caused an intermittent connection to join or weld itself. I've actually seen this happen and, well, is not ideal - typically fails again.
2. By actually starting the car you then tell J518 Entry & Start module "Yup all good, we started". Which switches the logic/program of that module to wait for car = OFF. So you've sort of hit CTRL-ALT-DEL on J518.
Follow?
So therefore for #2, the issue might lie in degradation of the function of J518.
If that is the case the jumper trick will always work, until if-or-when J518 finally gives up the ghost completely.
So I have two theories here :
1. Running current through the circuits and/or mechanical disturbance has caused an intermittent connection to join or weld itself. I've actually seen this happen and, well, is not ideal - typically fails again.
2. By actually starting the car you then tell J518 Entry & Start module "Yup all good, we started". Which switches the logic/program of that module to wait for car = OFF. So you've sort of hit CTRL-ALT-DEL on J518.
Follow?
So therefore for #2, the issue might lie in degradation of the function of J518.
If that is the case the jumper trick will always work, until if-or-when J518 finally gives up the ghost completely.
12-10-2016, 07:10 PM
#114
AudiWorld Senior Member
Hello Shark,
I think you did not follow what Doc did, he did NOT insert the jumper and then start the engine, I told him to do that to see if it would start by completing terminal 30 to create terminal 15, BUT when Doc inserted the jumper he heard air release and other things happening, SO he never turned the key on, nor tried to start it, instead he removed the jumper and reinserted another old relay he had and it started, I believe that it is to be a 40 amp relay, so the inexpensive $8 relay may not be, not sure, we will see what happens after Tuesday.
There is one more thing as you (Shark) has touched on, regardless of whom has been in the panel, it IS very odd that every time Doc accesses the area and removes and replaces the relay, it comes to life, There is a module for power right behind those three circuit breakers, so we should look into that, it very well may be a loose connection.
.
I think you did not follow what Doc did, he did NOT insert the jumper and then start the engine, I told him to do that to see if it would start by completing terminal 30 to create terminal 15, BUT when Doc inserted the jumper he heard air release and other things happening, SO he never turned the key on, nor tried to start it, instead he removed the jumper and reinserted another old relay he had and it started, I believe that it is to be a 40 amp relay, so the inexpensive $8 relay may not be, not sure, we will see what happens after Tuesday.
There is one more thing as you (Shark) has touched on, regardless of whom has been in the panel, it IS very odd that every time Doc accesses the area and removes and replaces the relay, it comes to life, There is a module for power right behind those three circuit breakers, so we should look into that, it very well may be a loose connection.
.
Jumping 30 to 15 @ relay J329 effectively duplicates a successful request to start from the module J518.
So I have two theories here :
1. Running current through the circuits and/or mechanical disturbance has caused an intermittent connection to join or weld itself. I've actually seen this happen and, well, is not ideal - typically fails again.
2. By actually starting the car you then tell J518 Entry & Start module "Yup all good, we started". Which switches the logic/program of that module to wait for car = OFF. So you've sort of hit CTRL-ALT-DEL on J518.
Follow?
So therefore for #2, the issue might lie in degradation of the function of J518.
If that is the case the jumper trick will always work, until if-or-when J518 finally gives up the ghost completely.
So I have two theories here :
1. Running current through the circuits and/or mechanical disturbance has caused an intermittent connection to join or weld itself. I've actually seen this happen and, well, is not ideal - typically fails again.
2. By actually starting the car you then tell J518 Entry & Start module "Yup all good, we started". Which switches the logic/program of that module to wait for car = OFF. So you've sort of hit CTRL-ALT-DEL on J518.
Follow?
So therefore for #2, the issue might lie in degradation of the function of J518.
If that is the case the jumper trick will always work, until if-or-when J518 finally gives up the ghost completely.
12-10-2016, 08:52 PM
#116
Prolly didn't read that right but who cares. OK couple of notes
Terminal #15 = Is traditionally known as +12V "bus", Ignition switched ON
Terminal #30 = Is Always hot (+12V)
The Start button is two stage design. Stage #1 activates Terminal #15, and of course Stage#2 is to hit the starter motor.
The way I read it the actual start command comes from the Engine ECU after it boots during stage1. Stage 1 will activate the Diagnosis bus or some sort on Can-bus action to get the other modules rocking. That is why ABS, and AT etc are popping up in the scans because they aren't activated due to the Term #15 electrical fault.
I am curious to see if a key is used exclusively to start the the car and do not use the button. What happens?
Terminal #15 = Is traditionally known as +12V "bus", Ignition switched ON
Terminal #30 = Is Always hot (+12V)
The Start button is two stage design. Stage #1 activates Terminal #15, and of course Stage#2 is to hit the starter motor.
The way I read it the actual start command comes from the Engine ECU after it boots during stage1. Stage 1 will activate the Diagnosis bus or some sort on Can-bus action to get the other modules rocking. That is why ABS, and AT etc are popping up in the scans because they aren't activated due to the Term #15 electrical fault.
I am curious to see if a key is used exclusively to start the the car and do not use the button. What happens?
12-10-2016, 09:54 PM
#117
AudiWorld Senior Member
Response in red.
Prolly didn't read that right but who cares. OK couple of notes
??? Who, you ???
Terminal #15 = Is traditionally known as +12V "bus", Ignition switched ON
Terminal #30 = Is Always hot (+12V)
Yes, this is what I have been saying all along...
Terminal 30 is always hot, it supplies the 12 volt power to the J329 relay, when said relay closes, it creates terminal 15, therefore sending power to all that terminal 15 supplies.
The Start button is two stage design. Stage #1 activates Terminal #15, and of course Stage#2 is to hit the starter motor.
Yes, this is a known fact.
The way I read it the actual start command comes from the Engine ECU after it boots during stage1. Stage 1 will activate the Diagnosis bus or some sort on Can-bus action to get the other modules rocking. That is why ABS, and AT etc are popping up in the scans because they aren't activated due to the Term #15 electrical fault.
Exactly
I am curious to see if a key is used exclusively to start the the car and do not use the button. What happens?
Doc also had a no start condition when he used the key besides push button.
??? Who, you ???
Terminal #15 = Is traditionally known as +12V "bus", Ignition switched ON
Terminal #30 = Is Always hot (+12V)
Yes, this is what I have been saying all along...
Terminal 30 is always hot, it supplies the 12 volt power to the J329 relay, when said relay closes, it creates terminal 15, therefore sending power to all that terminal 15 supplies.
The Start button is two stage design. Stage #1 activates Terminal #15, and of course Stage#2 is to hit the starter motor.
Yes, this is a known fact.
The way I read it the actual start command comes from the Engine ECU after it boots during stage1. Stage 1 will activate the Diagnosis bus or some sort on Can-bus action to get the other modules rocking. That is why ABS, and AT etc are popping up in the scans because they aren't activated due to the Term #15 electrical fault.
Exactly
I am curious to see if a key is used exclusively to start the the car and do not use the button. What happens?
Doc also had a no start condition when he used the key besides push button.
12-11-2016, 07:32 AM
#118
AudiWorld Member
Thread Starter
The cheap relay that is in there now is supposed to be a 40A, but now not sure on the quality.
I'll have good relays after Tuesday.
To me, and I'm not an expert in these matters (Yet!), there is something else going on. the Ctrl+Alt+Delete scenario made me laugh. This car is as complex as a PC!
Both of these issues have happened (coincidentally or not) after a pretty large temperature swing. The first time this happened, was the first week over 100 here in Utah this past summer. This more recent time was after the first week below freezing.
Maybe coincidence? Maybe thermal expansion/contraction in a contact or connection someplace?
I'll have good relays after Tuesday.
To me, and I'm not an expert in these matters (Yet!), there is something else going on. the Ctrl+Alt+Delete scenario made me laugh. This car is as complex as a PC!
Both of these issues have happened (coincidentally or not) after a pretty large temperature swing. The first time this happened, was the first week over 100 here in Utah this past summer. This more recent time was after the first week below freezing.
Maybe coincidence? Maybe thermal expansion/contraction in a contact or connection someplace?
12-11-2016, 08:39 AM
#119
AudiWorld Senior Member
Your car is more like a whole house automation system than a simple PC.
12-11-2016, 01:29 PM
#120
It is a complicated car for sure, I would say on a scale of a small industrial system or the Enterprise. Very high-speed comms, to give the appearance or response of a hardwired mess.
The engine start phase is one such quick-boot system and designed by VAG to be very robust and comparatively simple.
Restating again, in this case we have a voltage problem at Ignition ON. IF the mucking with the relays dosen't work then:
Read this: Terminal 15 relay - Club Touareg Forums
Same problem the guy found the wiring connection from J329 to J518 as the issue.
1. Consider also J518 may be a faulty module
2. As above, wiring in between - yes temp affects connectors. But the connectors in these cars are highly developed. It could be a cold solder joint in J518, a bad chip in J518.
3. A load off #15 pulling down the bus. I don't have the full wiring diagram in front of me but we
should look at is all loads off terminal #15. & Try to isolate. I would go so far as to remove all #15 loads (pull the fuses Scotty) until you are down to the essentials to start the engine. I know you are just country doctor dammit, but do follow?
Have to look at the wiring diagrams to get that list of fuses. Then monitor bus #15 with volt meter. It's too bad there wasn't a cheap/easy DC data logger for that - maybe there is??
PS: My door module electronics went bad, causing the window to open slow, then finally creep open by itself. The other side is going too. I am not too confident with the build quality of the electronics, especially if they have electrolytic caps, which are good for ~10 years +/- !
The engine start phase is one such quick-boot system and designed by VAG to be very robust and comparatively simple.
Restating again, in this case we have a voltage problem at Ignition ON. IF the mucking with the relays dosen't work then:
Read this: Terminal 15 relay - Club Touareg Forums
Same problem the guy found the wiring connection from J329 to J518 as the issue.
1. Consider also J518 may be a faulty module
2. As above, wiring in between - yes temp affects connectors. But the connectors in these cars are highly developed. It could be a cold solder joint in J518, a bad chip in J518.
3. A load off #15 pulling down the bus. I don't have the full wiring diagram in front of me but we
should look at is all loads off terminal #15. & Try to isolate. I would go so far as to remove all #15 loads (pull the fuses Scotty) until you are down to the essentials to start the engine. I know you are just country doctor dammit, but do follow?
Have to look at the wiring diagrams to get that list of fuses. Then monitor bus #15 with volt meter. It's too bad there wasn't a cheap/easy DC data logger for that - maybe there is??
PS: My door module electronics went bad, causing the window to open slow, then finally creep open by itself. The other side is going too. I am not too confident with the build quality of the electronics, especially if they have electrolytic caps, which are good for ~10 years +/- !
Last edited by Shark_V8; 12-11-2016 at 01:51 PM.