AVF TDI im Passat startet kalt manchmal seltsam!? | Posts 32+

Mike3BG wrote:

I also believe that the battery has an intermittent fault that is currently being masked by the charging process.

I don't think the charging issue is masking a problem with the battery cells. Wait until it happens more frequently and insist on another test. Then, it must be either the battery or the alternator (even according to the mechanic). It shouldn't be necessary to constantly recharge the battery. He can then test the Lima (alternator), and after that, he'll need to replace the battery.

Both the "Not testable" and "O.K." messages are snapshots representing the state of a cell's damage. Stay informed.

Hello!

I'm really angry and I'm currently writing directly to VW, even though it probably won't change anything .
They actually charged me EUR 25 for a one-minute battery test. The cup is overflowing, really!

Greetings.

Okay, then I will also write . Please also include the information about VW and Audi, and that it was a complaint due to the still-valid warranty/guarantee...

Hello, it's me again.

The email has arrived, and they have already responded (VW, not the workshop!). They say they will discuss it with the authorized workshop, and then that workshop will contact me. Well, I'm curious. Nevertheless, the workshop near me is not ideal , because if there is still a positive outcome, "the friendly" company could have put in the effort for me and certainly achieved it. I would have expected that, or is that really too much to ask?
"UnFreundlichen's" statement was as follows, verbatim: "What do you want from me? Are WE supposed to pay for the battery? If I return the battery, they will test it, and one week later I will have it back here, and we will be charged again." That's quite a harsh statement, isn't it? Or am I just being a bit sensitive? I then asked him if he thought it was okay to let me drive around with this EUR 180 battery and its intermittent cell damage. His answer: "No, but what can I do?" In short: if no one is responsible, the customer has to pay. He followed the guidelines, and everything else is completely irrelevant to him, even though he might agree with me.

Let's wait and see how things turn out. Perhaps they will both leave me in the rain, but then it will be final; that's the resolution I've made.
Anyway, I'm still very angry because I looked at the printout again. On one where it says "Not testable," the load voltage is 8.1V, and on the printout where the battery is completely okay, the load voltage is 8.6V. That's really a huge difference from the value of a charged battery . Who would believe that? The battery was neither discharged nor weak; it has a defect, and this test may have accidentally revealed it.

Greetings.

Me again.

Okay, next round. Just now, he started, and he had NEVER done THAT before in THIS way. While starting, it sounded like a tractor, with a hammering noise! I kept cranking and cranking, even though it sounded really unhealthy (despite the relatively fast cranking speed), and after about 10 seconds, I thought, "This thing is broken." I was about to give up, but suddenly, it started, as if nothing had happened. I turned it off again and immediately started it again, WITHOUT any problems. I had my laptop with me, so I immediately checked. SUCH a starting behavior MUST leave a trace. And? What was it? Yes, finally, there's one. And it's the 16705 engine speed sensor G28, showing an implausible signal. I then went to a (not MY!) workshop and introduced myself, explaining the problem I had mentioned earlier. He talked about starter current draw and battery damage, without even knowing about the battery issue. Guys, what am I supposed to make of that? He said the G58 is never just occasionally broken. He said it either works or it doesn't. Can anyone confirm this? The starting behavior is slowly becoming annoying, and it's happening more and more frequently now. Hopefully, they will get in touch soon.

Greetings.

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HE has never done THAT in THIS way before. While starting, it sounded like a tractor, with a hammering noise! I have been googling and googling, even though he sounded really unhealthy (despite the relatively fast crankshaft speed)

.

It seems like it's going to be like this:

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rodNeX wrote the following:: It sounds like one cylinder is firing and fighting against the starter motor...

If the crankshaft position sensor (G58) is responsible for initiating the fuel injection (ignition), then the starting behavior could be explained by a faulty G58 sensor. (I am currently not certain whether this is the case.) I think the pressure conditions of the PDs allow for this to happen even before the OT (optical transfer) process.

The theory of a defective battery would then be ruled out as the primary cause.

Hi,

wie, what does that mean? Is it possible that 'only' the G28 is faulty? One "expert" really acted as if it might work and might not. He said either it always works or never works . I would be happy if it were 'only' the G58, really. What do you think? But where is the sensor located? Is it easy to replace?

Greetings.

In my opinion, the crankshaft position sensor could be responsible for the strange starting behavior, rather than a completely collapsing battery voltage or even a stuck starter motor. If there are problems, it's likely two separate issues. The crankshaft position sensor couldn't have caused the initial battery reading, could it? And even if it's injecting fuel incorrectly, you mentioned that the starter motor speed wasn't affected. I find it unlikely that a power distribution module would permanently disable the starter motor. A brief drop in starter speed, perhaps for a fraction of a second, is possible, but then the starter would likely resume running. You're probably only noticing it in a way similar to that strange start.

The crankshaft position sensor would be the first thing to check, since the battery seems to be working again for now. I don't know where the sensor is located in your specific case. As far as I know, the crankshaft position sensor measures the speed of the crankshaft/starter ring. That's where I would look.

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But where is the donor located? Is it easy to replace?

It is located on the driver's side, behind the oil filter housing in the engine block, at the level of the crankshaft, and is only secured with one screw.
It costs 25 EUR, part number 038 907 319 E. But whether it's actually defective, I don't know. Anything else is possible, from a broken cable to an ECU failure, a loose crankshaft sprocket, etc. (I've seen it all before).
I would still exchange it because the effort involved is minimal. Possibly, it is also only contaminated with magnetic debris.

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If the engine speed sensor G58 is responsible for initiating the injection (ignition),

(which is currently (still) beyond my knowledge),

Amendment: According to the SSP (Specific System Parameters): The signal from the crankshaft position sensor provides information about the engine speed and the precise position of the crankshaft.
captured. With this information, the "injection timing" and...
calculates the injection amount.
In the event of a signal failure, the engine will be shut off.

Thanks, everyone.
I now know where that part is located. I've also found information about issues with the distributor rotor, etc., but I don't think that's the problem, because there's one thing we always have to keep in mind: it has never failed while driving, it has full power, it runs perfectly when it does run, without any misfires or anything else, and it always starts perfectly when it's warm. However, the very bad starting behavior I experienced yesterday has never happened before, which is why the error code related to the G28 sensor (unplausible signal) was initially dismissed. What worries me is that it sounded very strange, like a knocking sound. The description of a misfire might be similar to that sound. However, I haven't yet understood the technical details of how this happens, and whether the G28 could actually be the cause of this behavior.

Currently, I'm at the point where it would even be worth it to me to get a new battery and a G28 if I could just be sure that the error would be gone .

Sure.

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Written on: 03-11-2007, 12:14

and just now again:
The car was parked overnight and started cold in the morning -> no problem. Then I drove it for 10 minutes, parked the car, and started it again 1.5 hours later. Again, this terrible starting behavior, similar to what happened on Friday, but I didn't have to crank it for as long . I would say it took about 3 seconds. I haven't read the error codes yet, but I bet the same "G28: implausible signal" error is stored in the memory.
When it runs, it runs perfectly. I really don't understand it anymore. However, one thing is noticeable. The problems are accumulating now and occurring more frequently .

Greetings.

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Written on: 03-11-2007, 15:25

Okay, I've checked the error memory. This time, he didn't put anything inside. Was the organ music perhaps too short?

What would you do? VW wants the car to be diagnosed by an "independent" mechanic to rule out everything and to determine if the battery is actually defective or not. Now that the error memory has also started showing errors, they want to investigate that as well. I'm just afraid that they will charge me hundreds of euros and possibly find nothing, even though the problem might be a simple and easy fix. I don't know what else to do. If I start replacing parts based on suspicion and I can't locate the error, they will start from scratch again, and I'll have to pay for everything all over again. Do you actually have to pay for a diagnosis if nothing is found?

What should I do? Can anyone give me some tips on what I can measure with VAG-COM before a cold start? Because when it's running, ALL the values are okay, and it runs perfectly.
Is it true that if the G28 module is faulty, the motor could also shut off while driving? That's something he's never experienced before!

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Written on: 03-13-2007, 09:34

Okay, the car is at the "UnFreundlichen" . I'm curious to see what they find. Now, EVERYTHING will be checked from the beginning: resting current measurement, charging current/voltage, starter current draw, (grounding) connections, and all sorts of other things. Since Sunday, he has been starting up normally again, without any problems.

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Written on: 03-14-2007, 08:21

Okay, next day: Yesterday, almost everything was checked. This included the idle voltage, load voltage, starter speed, starter current draw, and all relevant control modules, with the result that EVERYTHING is healthy and okay. Also, it hasn't shown this malfunction again so far (possibly due to the slightly higher outside temperature ). Today, you want to perform another idle current measurement and a visual inspection of the wiring of the "starter circuit." I'm sure nothing will be found there either. And then it will get interesting. After all, that was the requirement to prove that it's NOT the battery. So, I'm curious to see if a new battery will solve the problem.

Greetings.

Okay, I need to vent my frustrations now.

They checked everything, but there were no positive findings. Of course, everything is always fine at the time of the measurements. However, the error still occurs every few days. And now, things are really getting complicated. I can't shake the feeling that I'm being scammed. Because they rely on the fact that they haven't been able to reproduce the error themselves. But if it occurs every few days, it should be possible. So far, the costs for troubleshooting have amounted to just over EUR 200. In other words, we have to give them the opportunity to find the error. And every action costs real money. They are not ruling out replacing parts, he said. Now the question: how much longer should I put up with this? "This could end up costing hundreds or even thousands of euros, depending on how long it takes them to find the problem. I have a plan: I could borrow a battery from a friend who has my old one. We would essentially swap batteries for a certain period. If the problem still occurs, then I can at least rule out the battery. But if the problem disappears, I'll know for sure that it's the battery, but then the problems start all over again. The 'unfriendly' person has already threatened me that my statement would still not be valid, because THEY, as a professional company, have to determine the defect." Basically, I have to essentially gamble and let them run tests for as long as it takes until the battery fault can be detected. Of course, I don't find that amusing, because a) it could potentially take a very long time, and b) they could tell me that they couldn't detect the fault. If the battery fault can be detected, all costs will be covered. But until then, it's pure luck, and there will be enormous costs involved. If things don't turn out in my favor... I don't want to think about that.
Therefore, my plan is: first, I'll borrow a battery. If the problem still occurs, I'll give up and replace parts blindly. a) Crankshaft position sensor, b) Ignition switch, c) Starter motor. Unfortunately, I couldn't find the right one for my AVF on Yabazzo. The part number and the BOSCH number are NOT the same. So, I'm also having a problem finding a relatively inexpensive AVF starter motor (for a 6-speed transmission) here.

I can't shake the thought about the possibility of only one cylinder firing, as mentioned in one of the earlier posts. But no one has been able to pinpoint the cause of such behavior. Could it be related to the starter itself? Or the counter-rotation? "The Unfriendly" also mentioned something about "fuel being pre-injected, but the full starting amount not being released due to insufficient starter speed." He also said that the PD (presumably referring to a specific type of fuel injection system) is *extremely* sensitive when it comes to starting. By "sensitive," he meant that if even the slightest thing is not right, it won't start properly, or not at all. The key phrase is "starter speed." However, based on my feeling, the starter seems to be spinning at a reasonable speed and with enough power in case of a fault. As I said, it's just a gut feeling.

"Please cheer me up a little, because I'm feeling completely down right now."

Thank you.

Greetings.

Since troubleshooting a VW can also be expensive, I would start by replacing the cheapest parts myself. The sensor for 25 euros and the battery would be good starting points. Make sure to buy a high-quality battery with a high cold-cranking current (significantly greater than 500A). The capacity is relatively negligible for starting; the cold-cranking current is the crucial selection criterion.

The VW expert is definitely right about the minimum RPM limit for the starting amount. If the RPM is too low, the engine won't start. And I'm not talking about half the RPM. If you're already at the limit, it's quite possible that it will start one day (e.g., with 310 RPM) and not start the next day (e.g., with 290 RPM). The mentioned speeds are only given as examples, as I don't have your dataset available.

Regards,
Guste.

Hello,
It's quite possible that the starter motor is operating near its limit, and in cold conditions, it might occasionally (in case of a fault) rotate slightly less, leading to the error. What's confusing me is that the starter motor doesn't just spin freely; the engine shakes differently than usual, and it's already making a combustion sound, as if something is igniting, but not enough to start the engine. I'd like to know if I should really just focus on the "starter chain." I can't say it enough: When it starts up, whether it's verschandeln or showing an error message, it runs perfectly!!!
Don't you think that if it were something completely different, the engine would also be making other noises or exhibiting other problems while driving?

But one thing is certain: I absolutely must not replace multiple parts at the same time, otherwise it will be difficult again to figure out what's causing the problem. I should have started with the battery. Then proceed step-by-step with G28, the ignition switch, and the starter motor itself.
The swap-test battery is the one I had in there before. It was charged and has been perfectly fulfilling its function in a Golf IV ever since, including with the auxiliary heating system.

Here's the translation:

"One more thing: Does it make sense to log every startup using VAG-COM? If so, I would do it, even if it's extremely time-consuming. But which measurement channel (MSB) values would be useful?" Does it display the starter motor speed?

Greetings.

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What was that? Yes, finally, one is inside. And specifically, the engine speed sensor

16705, G28, is providing an implausible signal.

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Please cheer me up a little, because I'm completely down right now.

It's your own fault .

It's not going to work out like that. You should start somewhere, and that somewhere is with the G28, instead of writing a novel here. Before we can rule out the possibility of this being a bug, we cannot provide further assistance here.
For the money you've wasted so far, you could have gotten a G28 and a new battery, and still had money left over.

I understand that. However, THAT is something I actually expected from the workshop. Instead, they start with a diagnosis and can't find anything. How can they, when the error only occurs very briefly and very rarely? Hindsight is always 20/20. If I had known that, don't you think I would have bought a G28 and a battery? If only it were that simple.

It would be great if someone could use VAG-COM to log the data. When the error occurs, I'm sure it makes a sound for at least 4 seconds; the first time it happened, it was probably 8-10 seconds. Therefore, the duration should be long enough to log some values. But which ones? Which ones make sense?

Best regards,

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Does it make sense to log every start with VAG-COM?

No, not until you've fixed/addressed the obvious mistakes.

And one more request: Please do not post any further responses until you can exclude the things mentioned above. It really doesn't make any sense and doesn't lead to a solution, as you've already noticed for almost 4 weeks now.