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02 - A6-3.0 Starting Issue - EPC

Old 02-02-2011, 01:28 PM
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Default 02 - A6-3.0 Starting Issue - EPC

Evening boys.

So here is the deal, the cold weather came into New england and the audi had issues starting. turned the key and it just wouldn't turn over or start up. eventually it did turn over and start up. at that point I went to Autozone to have the battery checked and they said that it wasn't charging. so I bought a new one even though the meter on the dash was at the usual 12-14V. well new battery in it and I figured all would be well. Come to find out it happened again while being on the road. to when it did turn over I checked in with Autozone to borrow their OBD scanner and it popped up saying camshaft sensor. So I went online and bought one from Autowarehouse. But their delivery took a bit so I had to wait. Well during that time the whole starting issue happened again. So I opened up the hood and put some started fluid into the intake. Well look at that, it starts right up. Had two more tries like that and same result. Last one took a bit longer but well it did start.

So now I am wondering if it is actually the camshaft sensor or could it possible be an electronic issue. I was thinking, sometimes cars have two fuel pump relay's. One for when the car is running and another one when the car is starting up. I checked the Bentley's Book and could only find one fuel pump relay and another one for additional air supply during starting.

Any takes ont his whole situation. I mean Cam Shaft sensor seems unlikely now...
Old 02-02-2011, 02:55 PM
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1) When you said "Come to find out it happened again while being on the road." what happened?
2) What was the generic OBD code?
3) Do you keep more than a quarter tank of gas, possible bad gas?
4) How many miles on this car?
Old 02-02-2011, 03:45 PM
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Originally Posted by jcman
1) When you said "Come to find out it happened again while being on the road." what happened? I went to the store and the car wouldn't start. Eventually it did start up and went into EPC mode. At that point I turn it off and start it up right after and its fine at that point.
2) What was the generic OBD code? - I cant think of the code but I will find out again, shouldn't be too long. This happens almost every other day.
3) Do you keep more than a quarter tank of gas, possible bad gas? I travel a lot. So I refill my tank every Sunday morning at CostCo. Always get 93 Octane.
4) How many miles on this car?
Currently 104,000 miles. Timing Belt done at 96,000
Old 02-02-2011, 04:37 PM
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I found this article from a Audi mechanic's answer to a similar problem. The EPC (Engine Power Control) light is a check warning light for the electronic throttle control. This vehicle has a "drive by wire" throttle control rather than a mechanical cable as in year past (<1999). The on board diagnostics of the Engine Control Module (ECM) must be scanned with VW/Audi capable scanner to check for stored Diagnostic Trouble Codes (DTC). Further testing and repair will be dictated by any retrieved DTCs. One thing you could try as an owner would be to disconnect the battery cables, hold them together, then turn on the ignition key to the on position for 30 seconds or so, shut off the key, reconnect cables. You can adapt the throttle in this vehicle by turning on the ignition to the on position (do not start). You should hear the throttle (top, rear of motor) go through it's adaptations. It only takes about 10 seconds. Now start the vehicle and drive as normal. If the EPC illuminations return further repairs will be necessary.
A cleaning of the throttle body butterfly valve followed by an adaptation of the throttle with a VW/Audi capable scanner may be attempted. The advantage to using the scanner is that you see the throttle go through it's adaptations, followed by a pass, or fail. Unless the throttle was significantly contaminated, the fault returns more often than not. It has been my experience that the throttle body assembly has usually failed and is replaced as a unit. MSRP for the unit it $625 and replacement should take approximately one hour (diagnosis/confirmation not included).
If immediately following "jump starting" of a dead battery the EPC is illuminated, a failed throttle body is also the likely cause.
If the idle fluctuates or is too low, a cleaning of the throttle body could correct the situation, but usually the EPC light will NOT be illuminated in this case.

Did the ECP light come on after the battery change?
Old 02-02-2011, 05:25 PM
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Yes it has. The EPC light will come on every time the car doesn't work.

The process is always the same: I will turn the key, the car wont start and will not turn over. Unplug all internal devices, like Valentine 1, and iphone charger, turn the radio off. start up again and again until it starts. Either with continue tries or with Ether being sprayed in the intake. It eventually will turn on and the EPC will be ON! at that point ill rev it up to about 5K let is idle for 5 sec count down and turn it off. On the next start it then will start perfectly fine.
Old 02-02-2011, 06:53 PM
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Well, I think the bone has been thrown.

You might consider vagcom and venture into it, or find an indy who knows these cars.

Or, kneel down to the mercy of the stealership.

Good Luck, member.
Old 02-03-2011, 06:38 AM
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Your advice to connect the battery cables together has me worried. There are many devices on board the vehicle that store a charge. A direct short like that is bad news. If you insist on doing this connect through a high resistive load like 1K ohm.
Old 02-03-2011, 03:27 PM
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Default Read it carefully please, not my advice.

Originally Posted by AR15Texan
Your advice to connect the battery cables together has me worried. There are many devices on board the vehicle that store a charge. A direct short like that is bad news. If you insist on doing this connect through a high resistive load like 1K ohm.
This was an article from a Audi tech to a person with a similar problem,
the same effect would be the positive clamp end touching ground that would discharge any capacitors if anything. Yes I would be concerned with a inrush static charge but that would be near to impossible to generate from a human hand and would only diminish based on the mass dissipation and shielding throughout the cars body.
Old 02-03-2011, 04:27 PM
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So i saw the epc in the title - but nowhere in the explanation. Did you leave something out?

Note: when the battery gets low, all kinds of odd alarms and gremlins can emerge.

G
Old 02-05-2011, 04:39 PM
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Default happened again...

well it happened again...

so I had some time and drove over to Autozone and used the OBD scanner and here is what we got out of it.

attached the pics I got from that event.

These pic links are different than the ones posted.

http://img823.imageshack.us/i/img0924yj.jpg/
http://img810.imageshack.us/i/img0925g.jpg/
http://img830.imageshack.us/i/img0926k.jpg/
http://img694.imageshack.us/i/img0927f.jpg/
http://img233.imageshack.us/i/img0928it.jpg/
http://img683.imageshack.us/i/img0930pf.jpg/
http://img121.imageshack.us/i/img0931x.jpg/


Car didn't start again kept holding the key turned to starting position. So today after that it had the check engine light on and the EPC was on as well.
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