AVF TDI im Passat startet kalt manchmal seltsam!? | Posts 48+

with "Sinn," I meant, is there anything at all (values in the MWB) that can be used ? If so, what and where? If not, then I don't need to bother doing it.
And I already think that ANY error log is better than none, but only if the data is usable, and I don't know yet whether that's the case. I think the starter motor speed is not visible, right?

You can see the engine speed in several data blocks, and it is also displayed when starting the engine.

You can also log the initial injection amount, which is also displayed in a measurement block labeled accordingly; you'll just have to identify which one it is.

Regards,
Guste.

Hello,
Okay, battery test passed? Battery. Record voltage during startup (possibly without a shut-off valve).

1. Use a multimeter, or preferably an oscilloscope with recording capabilities, to measure the voltage at the starter motor (at the positive terminal). Start the engine and record the voltage readings. What happens during a brief stall?
"Note: Voltage drop detected."

2. Connect the clamp meter to the starter's positive terminal to measure the starting current (note: this may indicate a mechanical issue). Does the Kemmen or version motor ignite? ''


3. Record the voltage of the starter solenoid coil.

Voltage measured with respect to starter motor ground.

Therefore, the battery and starter would either be the problem or they wouldn't.

Further tests would include, as mentioned before, checking the voltage drop across the mass conductors directly at the measurement point (possibly also at the chassis) to the battery's negative terminal, using a low voltage measurement range.
"Further details will be provided after the error has been identified."

Best regards,
derteileklaus

@guste100
@Teileklaus

Mike3BG wrote:

Just a moment ago, it started, and THAT is something it has NEVER done before in THIS form. 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 the car was broken. I was about to give up, but suddenly, it started running as if nothing had happened. I turned it off and immediately started it again, WITHOUT any problems. I had a diagnostic tool (Lappi) with me, so I immediately checked it. SUCH starting behavior MUST leave a trace of an error. And? What was it? Yes, finally, there's one. Specifically, the :evil:16705

engine speed sensor G28 is 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

Did you overlook this that's written above?

If the G28 sensor occasionally provides implausible signals during startup, and this leads to premature fuel injection, causing the engine to stall against the starter, it can easily result in this type of starting behavior. The current draw of the starter motor will then be incredibly high, and the battery voltage will accordingly drop, right?

It would feel like having the spark plug wires crossed in a gasoline engine.

Regarding the addition: According to the SSP (Specific Subject Publication), 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 motor will be shut down. (BM)

Hello,
I'm not entirely sure whether the system injects anything at all if the sensor doesn't provide a signal. That's why I would have ruled out the battery and the starter as potential causes.
Given the increased inrush current requirements (intermittently, and related to the starting problems), my suggestion was...
Testing starter motor mechanism: if the starter motor kicks back, the sensor is likely the issue.
I would have replaced it anyway, but now there's probably an error code in the memory again!
Best regards, derteileklaus.

P.S. I'll start by excluding the things I'm less familiar with. I'm not yet familiar with the VAG-COM, and I'll need a laptop first.

Quote:

I'm not entirely sure whether, if the sensor doesn't provide a signal, any fuel is injected at all.

There is no mention of a complete failure; according to the VAG regulations, it would no longer function in that case.

I'm not 100% sure that it's actually broken, but it's just to rule that out before we start guessing further.

Possibly, the signal is too weak, causing the control unit (due to the resulting voltage drop when starting) to not process the signals correctly.
The error code is certainly an indication of that.
I have not yet encountered a situation where this type of error is logged in the control unit (STG) as a result of undervoltage.

It has been mentioned several times that a "faulty" fuel injector can cause the starter motor to stop. In this case, the starter motor stops completely and no longer runs. Can someone please disprove this (surely the users who claim this can provide evidence)? No offense, just for my understanding .

Herr Antje wrote:

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 it is, then there are 2 problems. The crankshaft position sensor couldn't have caused the first reading of the battery measurement... And even if it's injecting incorrectly, you wrote that the starter motor speed remained unaffected. A power distribution module that permanently brakes/stops the starter motor seems unlikely. A momentary drop in starter speed, perhaps for a fraction of a second, is possible, after which the starter would run again. You're probably only noticing it in a way similar to that strange start.

@ BM
I didn't mean that the G would be completely eliminated, but rather for the moment of stopping over OT. Does he inject or not?
Let me ask this carefully...
If the engine is injected too early (in this case, even just for a very short time), and if he had recorded the starting current as I suggested, it would be visible in the high current draw. Then, swap the power supplies. A drop in power or voltage could indicate a power supply issue, or a problem with the power source itself.
It seems best to work through and post things bit by bit.
Has the problem reappeared with the new battery? (It's best not to start the SH beforehand, otherwise there will be another potential source of error due to the weakened (even a new) battery.)
dertürklaus
As a parts dealer, I would have immediately installed a new one for him, inspected the old one (what kind of performance does it have?), and if necessary, temporarily installed it in one of my own vehicles to see exactly what's going on.

Hello everyone!

Okay, the other battery is installed. Now we'll just observe. The sensor is already in the car, but if I install that too, I won't be 100% sure of the cause. Now I'm going to drive with the other battery. I haven't used any additional features like the auxiliary heater or the animal repellent since the problem started. It's possible that the problem will occur tomorrow/the day after, in a week, or even in 14 days. It would be interesting if the other car starts having the same problems, meaning we now have two observation subjects, so a doubled chance of failure. But I doubt it, because it's a Golf IV. While it's an AJM PD model, the starter is different, so it's not 100% comparable.

The near-stalling during startup happened only once, and it was a long time ago! The same goes for the engine cutting out even though it was running. It might be related to the ignition switch, but don't focus on that. The main issue is the strange starting behavior with the burning sound. The starter motor seems to be spinning fast enough, but it's hard to tell. As I said, this is just based on my gut feeling.

Regarding the sensor: as I said, it's been in the car since yesterday. I'm only concerned because everyone I've talked to has said, "Either the sensor works or it doesn't. There's nothing in between, because if there were, it would either cause problems with the temperature or even shut off completely!" I don't really believe that anymore.

I'll get back to you later.

Greetings.

teileklaus wrote:

if the engine is injected too early (in this case, only for a very short time incorrectly) and he had recorded the starting current as I suggested, then it would be visible in the high inrush current.

another one caught, please justify your statement, for example, based on my last post . Here, it's being talked about a constantly running starter motor. This single misfire increases the compression, and this increased compression therefore persists for seconds/minutes. That means the increase in compression achieved by the single injection remains perfectly preserved (due to 100% sealing piston rings and valves)...

My opinion:
A starter motor can only remain stuck if there is a voltage drop (e.g., a faulty battery), or a defect in the starter motor itself or its control circuit. The G28 sensor, or the injectors that are misfiring, are preventing the starter motor from stopping the engine.

Then he can leave the G28 installed for now, until there are problems again with uneven running (the issues with the starter motor getting stuck should already be resolved in my version). Perhaps a higher board voltage will also fix the G28 again .

Hello!

Again: the "almost stalling" incident happened only once and was quite a while ago. The car was parked overnight at approximately -12°C. Before starting, the SH (presumably the heater) was running for about 15 minutes, and then the engine was started. During the start, the starter motor felt like it rotated only about one revolution and almost stalled, but the momentum just barely got it through. However, THAT is not the primary problem, but rather what was described in the previous post. And based on what I understand, the G28 sensor might be the culprit.

Thank you.

Greetings.

Mike3BG wrote:

And as far as I understand, the G28 might already be to blame, or

Since you already have it, please do us a favor and instead of constantly asking us to speculate about how a defective G28 *might* behave, just tell us. That's starting to border on fortune-telling.

That doesn't help anyone. So, if you're still expecting our help, please first address the issues we've already mentioned and then post the results without any further intermediate posts.

Thank you and best regards.
Guste.

Herr Antje wrote:

teileklaus wrote: if the engine is injected too early (in this case, only for a very short time incorrectly) and he had recorded the starting current as I suggested, then it would be visible in the high inrush current. another one caught, please justify your statement, for example, based on my last post . Here, we are talking about a constantly running starter motor. Hello HerrAntje: "A very short pause" can also mean milliseconds. Okay, so it was just a brief, slightly more intense moment, but of course without stopping – I didn't write "stopped," did I? but the current briefly spikes, just like when there's a blockage. "As Herr Antje said..." My opinion: A starter motor can only remain stuck if there is a voltage drop (e.g., a faulty battery), or a defect in the starter motor itself or its control circuit. The G28 (or the injectors that are injecting incorrectly) are preventing the starter motor from stopping. How do you mean that? I was just thinking that premature injection could potentially block the investment. I haven't seen it happen on diesel engines yet, but it's been assumed to be a possibility. Could it be that the swing over the OT (over-the-top) point was insufficient due to a partially discharged battery (SH previously)? "Quote from Mr. Antje..." Then he can leave the G28 installed for now, until there are problems again with uneven running (the issues with the starter motor getting stuck should already be resolved in my version). Perhaps a higher board voltage will also fix the G28 again

.
Sure, here is the translation of the text from German to English:

"Antwort:"
"Answer:"
I still think we should put the G28 in the car - it's already there (spor.). Thermo error?
I'm tired of all the guessing; he should just do it and post it.
I'm sorry, I don't understand how to arrange quotes yet ''.

Sure, I will! You keep starting new discussions, which I personally think is good . That's why the forum is here .

Okay, so: the other battery has been installed since yesterday. Now I'm just going to wait and see. If the problem reappears, then the new G28 will be installed IMMEDIATELY. Then it's back to waiting. So, we'll wait. I will definitely get in touch, as you would expect.

Greetings.

First interim report:
It's not the battery or the G28 (engine speed sensor) . I didn't think I would get the result so quickly. This shows that it occurs more and more frequently, but it depends on the temperature. I have the feeling that it's worst when the engine isn't completely cold, but in the transitional phase. This morning, it was also slightly and briefly noticeable during the cold start, but when I drive for 5 minutes and then let the car cool down for 20 minutes to an hour, it's most noticeable then.

What is strategically better: to successively replace all the remaining distributors (e.g., G81 and G71/72), or the starter motor? A new starter motor from Yabazzo costs €162, while a used one from RAR with a few years and kilometers on it costs €145. What do you think? What should I do next?

Thank you all!

Greetings.

Hello,
Okay, so the problem is with the new battery. Has the donor reappeared?
Please tell me how and what you checked afterwards.
Best regards,
derteileklaus