A6 Not starting
#1
02-11-2014, 05:46 AM
A6 Not starting
Hi everyone.
Long story.
I have an Ag 2006 Model with130000Km
3Lt Multitronic BBJ engine JFG gearbox
Some months ago after washing the car it would not start. The only fault that had been reocurring prior to this was right rear tail light globe failure although the globe was fine.
The car was stuck in park and would not release . as we cannot leave vehicles outside our factory over weekends....they seem to dissapear, we had to move it into the workshop.
At this point I didnt know about the park release button so had to pick the car up with my fork lift to move it. Almost disastrous !
The battery was full even when testedout of the car with a load tester, but the car said it was flat.
A teck came round with his Vag Com moved the selecter lever and canceled some codes and we put in a new battery and the car started. Although it did just click at first as though the new battery was flat. After a few tries it started and ran fine.
Since then the problem has reocurred a number of times
At first simply getting the gearlever to move got it to start. But although the dash lights etc are all on fine it always behaves at first as though it has a flat battery for a few tries. Even sometime sonly running for a few seconds and dies.
Since the problem is becoming frequent the car is unreliable and we sent it in to a Audi VW specialist Not Audi themselves.
He has said that it needs a new gearbox ECU situated inside the gearbox part number 4F2910155M
However the fault codes are P0851 Park Neutral switch as well as P0706 Transmission range sensor.
The ECU is a third of the value of the car. So I am lothe to purchase one and find it isnt the probem.
So I am leaning towards the Park Neutral switch as the gearbox is operating fine.
Howevre one other fault which has come up previously was low voltage to stearing angle sensor and the low voltage starting worries me, when we get it to start.
We stripped the center consul and found that the plastic holder for the magnets which pass above the PC board were unclipped. The car is starting every time right now and I cannot create the fault at present so I dont know if I have fixed anything.
So question Would the ECU in the gearbox inhibit starting or would it be the PArk Neutral PC board at the selector lever.
The Tech is insisting its the ECU But I dont believe he checked any connections for dry joints or the like as nothing had been dissasembled.
I am more incluned to think along the lines of poor earths or something as the fault is intermittent.
Anyone had this problem and found a solution?
Long story.
I have an Ag 2006 Model with130000Km
3Lt Multitronic BBJ engine JFG gearbox
Some months ago after washing the car it would not start. The only fault that had been reocurring prior to this was right rear tail light globe failure although the globe was fine.
The car was stuck in park and would not release . as we cannot leave vehicles outside our factory over weekends....they seem to dissapear, we had to move it into the workshop.
At this point I didnt know about the park release button so had to pick the car up with my fork lift to move it. Almost disastrous !
The battery was full even when testedout of the car with a load tester, but the car said it was flat.
A teck came round with his Vag Com moved the selecter lever and canceled some codes and we put in a new battery and the car started. Although it did just click at first as though the new battery was flat. After a few tries it started and ran fine.
Since then the problem has reocurred a number of times
At first simply getting the gearlever to move got it to start. But although the dash lights etc are all on fine it always behaves at first as though it has a flat battery for a few tries. Even sometime sonly running for a few seconds and dies.
Since the problem is becoming frequent the car is unreliable and we sent it in to a Audi VW specialist Not Audi themselves.
He has said that it needs a new gearbox ECU situated inside the gearbox part number 4F2910155M
However the fault codes are P0851 Park Neutral switch as well as P0706 Transmission range sensor.
The ECU is a third of the value of the car. So I am lothe to purchase one and find it isnt the probem.
So I am leaning towards the Park Neutral switch as the gearbox is operating fine.
Howevre one other fault which has come up previously was low voltage to stearing angle sensor and the low voltage starting worries me, when we get it to start.
We stripped the center consul and found that the plastic holder for the magnets which pass above the PC board were unclipped. The car is starting every time right now and I cannot create the fault at present so I dont know if I have fixed anything.
So question Would the ECU in the gearbox inhibit starting or would it be the PArk Neutral PC board at the selector lever.
The Tech is insisting its the ECU But I dont believe he checked any connections for dry joints or the like as nothing had been dissasembled.
I am more incluned to think along the lines of poor earths or something as the fault is intermittent.
Anyone had this problem and found a solution?
#2
02-11-2014, 01:09 PM
If it was the park switch, I would think it would not start at all, i.e. it wouldn't behave like a dying battery. I had my transmission rebuilt some time ago, and if my car isn't all the way in park, it just wont do anything
#3
02-12-2014, 01:32 AM
Those were my thoughts exactly and hence my reluctance to spend the money on a gearbox TCU. The problem is deeper than that Im sure.
#4
02-13-2014, 02:24 AM
Some more info. Once again the car wont start.
We find that there is no indication of park neutral etc.
After releasing the selector lever and moving the gearlever backwards and forwards a number of times the car starts to click the starter solenoid. It seems the more you move the selector lever the greater the starting current and it everntualy begins to crank and start. After moving the selector lever back and forth eventualy the indicator on the dash starts working. as soon as that happens it begins wanting to start.
Battery is still fully charged.
We find that there is no indication of park neutral etc.
After releasing the selector lever and moving the gearlever backwards and forwards a number of times the car starts to click the starter solenoid. It seems the more you move the selector lever the greater the starting current and it everntualy begins to crank and start. After moving the selector lever back and forth eventualy the indicator on the dash starts working. as soon as that happens it begins wanting to start.
Battery is still fully charged.
#5
02-14-2014, 05:57 AM
It seems there are not may people here who know much about this fault.
Anyway here is some more info. We inspected the connector to the TCU It had been damaged by someone in its history. I checked with Audi and they say no repairs or service was done on the gearbox by their service centres while it was under motor plan. That is all the way to 100000 KM
Interesting as it should have had an oil change in the CVT box at around 60-90Th
I had all that done as soon as I purchased the car as a caution and its now possible that the guy who did it for me broke it.
Either way it was not the problem and all the groves were still in place to make the plug secure after its twisted. We just cleaned it and sealed it.
After much e mailing and phoning worldwide it seems the TCU range findermay well be the problem however it doesnt account for it behaving as though it has low voltage when it starts....when it does! It has two fault codes P0706 Range sensor and also P0851 Park Neutral switch.
It seems that the 0851 code will not come up when the TCU is repaired we will see.
At least the PC boad at the selector isnt as bad as the TCU in price if it is also faulty.
So next we will remove the TCU and check the range sensor magnets and ensure its clean and not covered in filings. If it is we will clean it up and change the oil and see if that helps. Failing that I have found someone who can repair the unit for a tenth of the price with a year guarantee.
I will report further.
Anyway here is some more info. We inspected the connector to the TCU It had been damaged by someone in its history. I checked with Audi and they say no repairs or service was done on the gearbox by their service centres while it was under motor plan. That is all the way to 100000 KM
Interesting as it should have had an oil change in the CVT box at around 60-90Th
I had all that done as soon as I purchased the car as a caution and its now possible that the guy who did it for me broke it.
Either way it was not the problem and all the groves were still in place to make the plug secure after its twisted. We just cleaned it and sealed it.
After much e mailing and phoning worldwide it seems the TCU range findermay well be the problem however it doesnt account for it behaving as though it has low voltage when it starts....when it does! It has two fault codes P0706 Range sensor and also P0851 Park Neutral switch.
It seems that the 0851 code will not come up when the TCU is repaired we will see.
At least the PC boad at the selector isnt as bad as the TCU in price if it is also faulty.
So next we will remove the TCU and check the range sensor magnets and ensure its clean and not covered in filings. If it is we will clean it up and change the oil and see if that helps. Failing that I have found someone who can repair the unit for a tenth of the price with a year guarantee.
I will report further.
#6
02-18-2014, 07:34 AM
Final update for now. After purchasing an EMO workshop manual we decided to tackle removing the gearbox TCU ourselves. We found that the magnets within the gearbox which have to interact with the unit were covered with a clump of very fine filings picked up in the oil. Not filings as you would expect from a damaged box but almost a black sludge. These had covered the magnets making it impossible to differentiate between each serepate one. So after cleaning them off very carefully and changing the gearbox oil it is currently all working fine again. Time will tell if we have actually solved the problem. Evidently we can expect a failure on that TCU soon anyway as its past its known sell by date.
Others things we found out while investigating the problem and searching for advice from all sources was that the dealership who handled all services fron new to 90000KM did not sevice the gearbox at the appointed time as they should have. Morel of the story is while your vehicle is under motor plan make sure you double check that the full service your entitled to gets done. This was a critical step and contributed to my fault as oil changes on the CVT unit are critical as is using the right oil.
Also this TCU failure is a known fault and there has been a court case in USA wherby the court determined that Audi is responsible to replace the unit for up to ten years or 200000KM.
Of course in my Country they dont believe that this should effect them at all.
Others things we found out while investigating the problem and searching for advice from all sources was that the dealership who handled all services fron new to 90000KM did not sevice the gearbox at the appointed time as they should have. Morel of the story is while your vehicle is under motor plan make sure you double check that the full service your entitled to gets done. This was a critical step and contributed to my fault as oil changes on the CVT unit are critical as is using the right oil.
Also this TCU failure is a known fault and there has been a court case in USA wherby the court determined that Audi is responsible to replace the unit for up to ten years or 200000KM.
Of course in my Country they dont believe that this should effect them at all.
Last edited by RMD; 02-18-2014 at 08:01 AM.
#7
02-20-2014, 02:02 AM
I spoke too soon!
The vehicle has been on soak test. IE: stands in the parking lot and is moved around from workshop to workshop . Starting every time no problem. Then since the problem first started after washing the car, my tech started and switched off the car about three times. Got out and threw a bucket of water over the bonnet and windscreen and guess what It wont start.
Now after getting it going again the engine is hunting you name it.
Well the TCU has now been removed and sent off for a repair. At least we will have eliminated one possibility. The Plenim chambour has been inspected and cleaned out . The drains were checked all wires and earths inspected looking for a possible rubbed through wire or the like. All the relays and plugs have been checked and are all spotlessly clean and corrosion free. So far nothing found. So now we will replace the TCU and tryagain.
The vehicle has been on soak test. IE: stands in the parking lot and is moved around from workshop to workshop . Starting every time no problem. Then since the problem first started after washing the car, my tech started and switched off the car about three times. Got out and threw a bucket of water over the bonnet and windscreen and guess what It wont start.
Now after getting it going again the engine is hunting you name it.
Well the TCU has now been removed and sent off for a repair. At least we will have eliminated one possibility. The Plenim chambour has been inspected and cleaned out . The drains were checked all wires and earths inspected looking for a possible rubbed through wire or the like. All the relays and plugs have been checked and are all spotlessly clean and corrosion free. So far nothing found. So now we will replace the TCU and tryagain.
#8
02-26-2014, 08:57 AM
HELP!
Ok we received the repaired ECU and installed it. We also changed the oil.
Guess what the car starts. But NOW the radio is coming on and off every few seconds , the CD player is not working , wont even edject CD's The Climate controll is not interfacing with the MMI????????
WHATS UP?????
Ok we received the repaired ECU and installed it. We also changed the oil.
Guess what the car starts. But NOW the radio is coming on and off every few seconds , the CD player is not working , wont even edject CD's The Climate controll is not interfacing with the MMI????????
WHATS UP?????
#9
03-07-2014, 06:17 AM
Ok so I gave in and purchased my own Ross Tech unit.
How this came about I dont know and how it may or may not be related to the gearbox ECU failure I dont know but the Bluetooth unit located under the passenger carpet ( Right drive) has failed. It no longer communicated or allows coms through the fibre optics.
Audi want R9000.00 or $850 for the unit. It has exactly one little pc board in it.
I found one online for $94.00. It should arrive tomorrow.
Ok so the syptoms were that the radio was coming on and off every 3 seconds. The Aircon did not interface with the MMI. CD changer would not play and the phone said please wait.
Afetr scanning and determining that the Optic loop was not communicating between units and the telephone unit was also electricaly dead. We joined the optical cables together to create a loop and everything worked except the phone( obviously)
How this came about I dont know and how it may or may not be related to the gearbox ECU failure I dont know but the Bluetooth unit located under the passenger carpet ( Right drive) has failed. It no longer communicated or allows coms through the fibre optics.
Audi want R9000.00 or $850 for the unit. It has exactly one little pc board in it.
I found one online for $94.00. It should arrive tomorrow.
Ok so the syptoms were that the radio was coming on and off every 3 seconds. The Aircon did not interface with the MMI. CD changer would not play and the phone said please wait.
Afetr scanning and determining that the Optic loop was not communicating between units and the telephone unit was also electricaly dead. We joined the optical cables together to create a loop and everything worked except the phone( obviously)
#10
03-10-2014, 09:06 AM
Just to close off this thread.
The new unit arrived and is installed and problem is solved.
So: Radio intermittent on and off every 3 seconds. Air con not communicating with MMI, Telephone unnavailable, Shows Please wait and hangs.
Telephone unit under left front carpet failure. The Telephone unit blocks communication between the other components in the MOST loop.
Diagnostic test shows that the telephone unit has both a electonic and optical failure.
Random other units in the loop show optical falures but not electrical failures.
If the telephone unit 77 optics are looped together, This can be done without the Audi tool by carefully prising the optical cables from the line connector and plugging them together using something like a piece of PVC offcut. This way the retest will show all the other units operating and in fact the radio will work properly and the rest will also work except not the telephone.
Optical Bus Diagnostic : 3dB Attenuation
Controller Electrical Optical
19-CAN Gateway OK OK
07-Control Head(High/D3) OK ERROR
0E-Media Player 1 OK OK
77-Telephone ERROR ERROR
47-Sound System OK ERROR
56-Radio OK ERROR
37-Navigation OK OK
IE: a quick test without a Ross Tech unit would be to lift up the left side front carpet and remove the unit. Unplug the optics and join them If the radio stops going on and off. You found the problem.
Search online for a unit of the same part number. I found a brand new one.( Lucky)
No coding was required and all is working.
This repair would have cost me R13000.00 about $1200 from Audi.
The new unit arrived and is installed and problem is solved.
So: Radio intermittent on and off every 3 seconds. Air con not communicating with MMI, Telephone unnavailable, Shows Please wait and hangs.
Telephone unit under left front carpet failure. The Telephone unit blocks communication between the other components in the MOST loop.
Diagnostic test shows that the telephone unit has both a electonic and optical failure.
Random other units in the loop show optical falures but not electrical failures.
If the telephone unit 77 optics are looped together, This can be done without the Audi tool by carefully prising the optical cables from the line connector and plugging them together using something like a piece of PVC offcut. This way the retest will show all the other units operating and in fact the radio will work properly and the rest will also work except not the telephone.
Optical Bus Diagnostic : 3dB Attenuation
Controller Electrical Optical
19-CAN Gateway OK OK
07-Control Head(High/D3) OK ERROR
0E-Media Player 1 OK OK
77-Telephone ERROR ERROR
47-Sound System OK ERROR
56-Radio OK ERROR
37-Navigation OK OK
IE: a quick test without a Ross Tech unit would be to lift up the left side front carpet and remove the unit. Unplug the optics and join them If the radio stops going on and off. You found the problem.
Search online for a unit of the same part number. I found a brand new one.( Lucky)
No coding was required and all is working.
This repair would have cost me R13000.00 about $1200 from Audi.