AVF TDI im Passat startet kalt manchmal seltsam!? | Posts 16+

@Ulf
Okay, I agree with you, but I have to ask you again if this could also happen while driving? It has NEVER broken down while driving!

Greetings.

@Mike

ulf wrote:

Voltage drop at terminal 15 due to the movement of the ignition switch.

Do you turn the key even while driving?

Okay, but why has it never turned off even when it's warm? Is it a coincidence that it only ran in scenario b once so far? Hmmm.

Greetings.

Mike3BG wrote:

Okay, but why has it never turned off, even when it's warm? Coincidence, because he has only done case b) once so far?

That seems most likely to me.

Quote:

b) The starter motor turns the engine one revolution and then sounds as if it's getting stuck (the engine remains audible and stops). Then there's another strong jolt, and it starts running. a) and b) always only in the cold state!

Quote:

I still maintain: this fits perfectly with a voltage drop at terminal 15 due to the ignition switch being moved back. The MSG recognizes this as a completely normal stop command, and therefore does not report any error.

I've also experienced similar errors before, but in my opinion, it doesn't quite match the starter motor issue, which seems to be getting stuck in a "engaged" state for a short period.

The person who started the thread is looking for a foolproof recipe, but is unwilling to exclude simple things (e.g.,). Replace the battery as a test, even if it's relatively new.

Such errors can have various causes, so he should start by investigating. He can't get anywhere just by arguing.

Hi everyone.
.....not at all. I was just about to write. I'll start by testing the battery, checking the connections to the starter, and then I'll try replacing the ignition switch. It definitely requires a diagnostic tool to read the codes, so adjustments will be necessary, right? Is there a documentation available on how to adapt the ignition switch to the WFS (presumably a specific system or device)?

Perhaps it's even two different problems!

What influences the engagement and disengagement of the starter motor? Does the magnetic switch play a role? Can you now buy or trade them individually?
I also have the feeling that if it doesn't start 100%, the engine vibrates less when starting. In other words, with the Passat, you notice it very clearly because the whole car shakes a lot. But sometimes it's less, as if the starter is spinning freely, the engine is already turning, but it's not shaking. Funny, right?

Thank you.

Greetings.

BM wrote:

Quote: I still maintain: this fits perfectly with a voltage drop on terminal 15 caused by the ignition switch being moved back. The MSG recognizes this as a completely normal stop command, and therefore does not report any error. I have also experienced such errors before, but in my opinion, it doesn't fit with the starter motor issue, which seems to get stuck in a "engaged" state for a short time.

Okay, the starter motor is not receiving a signal on terminal 15.

I also do not claim that terminal 15 is responsible for all symptoms. Probably, there are more problems with the car...

Okay, here are a few more things: I have a feeling that the lights were still on after they died. It's possible that the contact for terminal 15 only failed for a very short time (at the moment it turned off) and immediately worked again, but shouldn't the entire control unit be completely unresponsive if terminal 15 is not supplying power?

I'm getting a battery test tomorrow afternoon. Depending on the diagnosis, I'll replace the Kl.15 contact at the ignition switch. It's a separate piece that just plugs into the back of the ignition switch. It costs about 20 euros. I also suspect that there are two separate issues: the battery AND the Kl.15 contact. I would be "happy" if that's the case. Because the battery is only 3 months old, and it's certainly something that should be replaced without any issues.

Then we'll see what happens next.

Magnetic switches are not sold individually. It is located on the starter motor and is only available for purchase as a complete unit with it.

Greetings.

Hi everyone.

Yesterday, the moment finally arrived, and I have to say, I'm really frustrated. The VAS 5097A testing device for battery testing was connected, and it spat out a piece of paper with nothing on it, except the note "Not testable." This means the tester doesn't even start the test. The mechanic said that there could be many causes for the problem, such as: a) discharged, b) broken, c) blah blah blah, etc.
Then we checked when it was actually new last year. It was in February 2006. It was manufactured in week 28 of 2005, but apparently wasn't filled until the delivery date of 02/2006. Please, how can it be that the original battery lasted 4 years and then was discharged, I got a new one, and that one was also discharged after exactly 1 year? We measured the quiescent current after replacing the battery, and it was absolutely okay and normal. His suggestion was to measure the charging current of the alternator. If it charges too little gradually, then that would happen. Okay, I can understand and see the logic in that. But he couldn't explain one thing to me. Why wasn't the battery testable yesterday, even though I didn't use the SH or anything else? And it starts up normally, so it can't be that bad, right?
We agreed that I would bring the car in, and they would re-test it. If the test results are still blank or the device shows a negative reading, I will get a new battery. However, I would still like to have the alternator load test performed, but I've heard it's quite expensive. Can anyone confirm this? My question is whether I can perform this test myself (I have a multimeter) and whether it can be done with VAG-Com. Does anyone know the reference values that the German Federal Motor Transport Authority (LiMA) is obligated to provide in all cases?

What do you think about that, and what connections might there be with the starting problems? Okay, that the starter motor got stuck once might be related to that. But after that, it started normally again, which is strange. But maybe the battery has a minimal defect that only manifests very rarely . Since my first post, I haven't had any problems starting the car. But eventually, it will come back sporadically, and I can feel it.

Greetings.

Mike3BG wrote:

However, I would still like to have the alternator tested, but apparently, that is supposed to be quite expensive. Can anyone confirm this?

No. For me, it has never cost anything to use ATU services so far. Someone also reported paying EUR 15.00 for the complete test (battery and alternator).

The battery is probably dead. If it's not due to the alternator, then it was likely a manufacturing defect. The new one will probably last longer...

It's quite funny. The Audi repair manual from the dealership states that if the diagnostic system displays "not testable," the battery is defective and needs to be replaced, without any charging or further inspection. The VW manual, on the other hand, states that the battery should be charged and the test repeated. What do you think about this? Can someone explain it to me? I'm afraid that a charge might skew the results, and the tester might give a falsely positive reading, even though the battery is failing.

Greetings.

If you drive for long enough, your battery should be fully charged, or at least it should have been. Only if your alternator is faulty will charging make a difference. That's why I would recommend getting the alternator tested first. You're probably going to charge it at home anyway, right? Then you'll start the car again and drive a bit further. In that case, the charging won't really help much. Otherwise, just say that you're charging and don't make it a .

Hello!

I drive every day, but not very often. Mostly between 1500 and 2000 trips.
Yes, I would use the CTEK XS7000 to charge it.

Unfortunately, it's not that simple. I've already considered that. If they charge the batteries themselves, it's possible that a different result will be obtained, which would then lead to a refund. That would be a stupid thing to do.

Perhaps someone could give me a tip on how to properly measure the charging current of the alternator? Can VAG-COM do that, or not?
Does A.T.U do that for free? I don't think that's the case with us . Why would they do that? If everyone just came there, for no reason, they would have a lot to do and do it all for free? Hmmmm.
What are the specifications for a 120A alternator in a 3BG TDI PD (96kW) engine? The charging voltage should be at least 13V, right? And what about the charging current? How is that normally measured? With a clamp ammeter connected to the battery?

Thank you.

Greetings.

Mike3BG wrote:

Maybe someone could give me a tip on how to properly measure the charging current of the alternator!? VAG-COM can't do that, right?

Not directly, but an estimate can be made based on the on-board voltage in some mobile workstations.
Make sure the engine is warm at idle, and observe the onboard voltage, which should be around 14.5V.
Then, one by one, activate the high-power consumers: lighting, high beams, rear window defroster, apply the brakes, turn on the heater at full power, activate the seat heaters...
The voltage should ideally drop significantly only later (after the headlights, brake lights, and rear window).
When everything is properly adjusted, the voltage should return to its normal level at around 1200 rpm when you slightly increase the throttle.
If that's not the case, the LiMa (lithium-ion battery management system) probably won't charge the battery properly.

Quote:

Maybe someone could give me a tip on how to properly measure the charging current of the alternator!

You can use a clamp meter to check this; it simply clamps onto the positive or ground cable of the battery. When the engine is running and some consumers are turned on, you can see how much current is flowing in which direction. From this, one can derive the charging current in relation to the power consumption and the motor speed.
You can probably save yourself the trouble. If the alternator isn't providing enough charging current, the battery will drain relatively quickly, to the point where the car won't start. It's also possible that it's sulfated (due to frequent use with a specific type of battery) and therefore can't accept enough charge, even though it's not fully charged.
My suspicion remains that the damage is due to cell injury, which often occurs sporadically.

Update:
It has happened exactly what I feared.
The battery was charged, but the "Not testable" message no longer appeared -> According to the test report, the battery is OK. The arrow points almost to 100%! The load voltage is 8.6V, and neither the dealer nor VW wants to do anything . I am extremely angry. They only refer to the test report. Is that even legal? Is there a way to prove that the battery is not 100% okay and has a cell defect?

When I plugged it in, I noticed it wasn't completely empty, because it only took about 3 hours to fully charge. The "Magic Eye" indicator was green from the beginning, indicating everything was okay. I could also start the car normally before charging, even with the auxiliary heater on. However, it sometimes had some issues. I also believe that the battery has an intermittent fault that is currently being masked by the charging process .

Greetings.