Voltage drop during (TDI) start

Hi.

Do you know what the normal values are for this?

I'm measuring up to 0.6 volts between the negative terminal of the battery and the AGR (which should be verschandeln and far away) during startup.

After that, it becomes negative, so I even have waste even when charging.

m;

Why did you double-check the measurement?

Quote:

For what reason did you re-measure?

I think he has too much time or is bored .

dieselmartin wrote:

Do you know what values are considered normal in this case?

I would calculate it myself, using the formula U = R x I.

You can calculate the resistance of the grounding cable based on the specific resistance of copper: a cable with a cross-sectional area of 1 mm² and a length of 1 meter has a resistance of approximately 18 milliohms.

For the middle register when playing the organ, I would set the current at approximately 150-200 amps.

Quote:

After that, it becomes negative, so I even have waste during charging.

Logically, if the charging current flows through the cable in the opposite direction to the organ current

Deus Violentia wrote:

For what reason did you re-measure?

Due to the starting behavior with the old and the new battery.

The old car either wouldn't start at all, or it would start with a "well, okay" – depending on how it felt at the moment.

Since I didn't feel like doing that anymore, there was a new one.
That's how he always starts.
But it's also always that kind of "well, okay" feeling.

I remember that it used to turn on _immediately_, but now it needs some time to warm up.

And I'm still looking for the reason behind it.

m;

@Martin: I don't know if it's the same on the Passat, but there's a known issue with the light switch on the A4 8E.
It can't hurt to try it out. At Audi, there is at least a Technical Service Bulletin (TPI) related to this issue.

It can be tested relatively easily. If you set the light switch to position '0', it starts without any problems, but if it's in any other position, the engine starts very reluctantly.

Regarding your original question. My battery voltage drops to 11.7V when I start the engine.
At rest, the voltage is approximately 12.6V.

Quote:

My battery voltage drops to 11.7V when the engine starts.

Are you only talking about pre-rinsing?!

The 11 volts will never sustain the battery during starting, right?

If that's the case, I'll be at your place this weekend and want to see it.

m;

Could it be that Siemens ECUs also have this ridiculous RPM threshold for the initial fuel injection amount? That could be a reason why it's difficult to start.

Does he do it in cold weather (like it is right now)?

Currently, it starts up neither better nor worse.
But our BLS model, despite having significantly higher mileage, starts more readily.

What is it?

Quote:

this stupid speed threshold for the initial amount

m;

In many TDIs, fuel injection only begins after a certain engine speed. Depending on the software version and temperature, this can be anywhere from 200 to 280 RPM. If there are problems with the starter motor or battery, or if contact corrosion occurs, the engines may experience starting problems (especially when warm), even though the hardware itself is not actually defective.

Who can take a look inside a 03G 906 018 EM SW 4369 ?

This could very well explain why the BMP with 125,000 km and the BLS with 135,000 km start up much more abruptly (both are mPD BOSCH with DPF), and why my Siemens injector is so hesitant.


Can this be detected using a TURBO-Log?
Speed and pumping duration... so, just log block 001?

m;

My BMR (presumably a piece of equipment) has started up three times in the last 3 weeks, but only after about 2 minutes of trying.
"It had a cold start problem twice, and once my wife stalled it after about a minute of running."
The error memory is clear. I haven't measured the voltage drop yet, because I never have a measuring device with me when the car won't start.
Okay, so I charged the battery yesterday, let's see if the problem with it not starting happens again.
By the way, the car has 190,000 kilometers on the odometer. I don't know how old the battery is, but I bought it 2.5 years ago with 146,000 kilometers, and the battery is the original VW battery.

Heinz,

There should be some kind of production week marking on the battery somewhere – at least, I seem to remember seeing something like that.

Do you have VCDS? Can you possibly generate a detailed log from the start?

Thank you.
Martin.

I can't definitively prove the threshold yet, but it seems to be there.

This morning, after a night with a temperature of 2 degrees Celsius, it started up better than ever.

After driving around the city for a while, changing tires, etc., it's not so good anymore.
Log MWB001 Turbo:
Two sensor readings indicated a motor rotation, but apparently no fuel was injected.

m;

Okay, I've created a log file; I hope it's helpful to you.
The car started perfectly this morning at 5 degrees Celsius.
The battery appears to be the original one. There's a marking "42/06" on the negative terminal, which I believe indicates the 42nd week of 2006.
The car was first registered in November 2006.

Heinz.

Unfortunately, the log file is unusable because the time and energy values are decimal numbers, but they are separated by semicolons ( instead of spaces, like the columns.

32.4 mg/h at 3 degrees Celsius is a good starting point.
0.87 seconds from the initial rotation to the point where the electric current is cut off.

At 34 degrees Celsius, I had 19.5 mg/H and 0.53 seconds.
I'll do a colder log tomorrow.

m;