Funktionsweise Vorglühanzeige | Posts 16+

Conflicting data for CR motors:
- SSP 325 (Audi 3l V6 TDI) describes a phase-shifted PWM control for the glow plugs of the 3l V6 TDI engine, meaning individual control for each glow plug.
- SSP 351 (VW 3l V6 CR TDI) also provides additional information on individual spark plug monitoring;
- SSP 420 (Audi 2.0 CR TDI) provides a phase-shifted PWM control signal for the glow plugs, meaning individual control; it describes the preheating system as being self-diagnosing.

- die Schaltpläne für alle A4 8K CR Motoren (4R, V6, bis Mitte 2014) zeigen eine fast klassische Anordnung: eine 10 mm Leitung mit Sicherung im Motorraum, hin zum Steuergerät für Glühzeitautomatik, darin (alles eindeutig verdrahtet vom Eingang zum Ausgang durchgezeichnet!) einen Halbleiterschalter (FET) und danach die Verzweigung zu den Glühkerzen, dann vom Stg zu den einzelnen Glühkerzen. Mit dem Bild ist eine Überwachung er einzelnen Kerzen nicht vorstellbar. Die Logik im Stg wirkt nur auf den FET. BeIn certain engines, individual cylinder heads have a sensor for cylinder pressure.

SSP documents and wiring diagrams don't match.
I'm going to check with VCDS now to see what diagnostic options are available.
I only observe noticeable pre-glow at temperatures around 5° Celsius, similar to the old 1Z model. Above that temperature, the engine starts immediately.
hg
Herbert.


PS: The RLF (presumably a specific entity or role) is again referring to the individual control and monitoring of the GK (likely a piece of equipment or system).

Hi HerBärt!

The preheating control unit is shown schematically in the circuit or wiring diagram so that interested professionals can understand its function.
And there's nothing about FETs there - I see a bipolar transistor .

The PWM and offset in the respective control system serve to reduce the load on the internal power supply and, furthermore, to regulate the heating power (e.g., 4.4V candles are used that would melt at 12V!!!).

So, don't get too hung up on the schematic diagrams...

Best regards from Munich!

If a schematic diagram shows four outputs from a module, and these are clearly represented as converging into a single node within the module, then that is unambiguous.
If that's not correct, then the published construction documents are simply wrong. A qualified acceptance test would not pass in that case.
hg
Herbert.

Servus HerBärt!

I must correct myself at the beginning: The block diagram of J179 also shows a suggested FET after the control logic. This was clarified with HerBärt via private message.

Ohne jetzt unbedingt das letzte Wort haben zu wollen finde ich die gewählte Darstellung des Vorglüh-StG's trotzdem i. OPlease provide the text you would like me to translate from German to English.

In some types of SSPs (Solid State Power Supplies), it is represented entirely without internal circuitry, simply as a logic element. However, the input of 10² in the power section reveals the input, and the GSKs (presumably a specific component or marking) indicate the output of the solid-state generator (StG).
For those who cannot see the cross-sections, the schematic function of the part provides further clarification.
Certainly, it would have been more accurate to draw the FET four times; for the 6-cylinder engines, then six times, etc.
Then, of course, the next person comes along and complains about the missing current-limiting resistor in series with the ground fault circuit interrupter (GFCI) for compliance with the Material Safety Act (MStG), the feedback to the logic in the J179 module, etc.
At the end, someone wants to know about the physical design, the external connections, and the microcontroller programming, because how else can they assess what the device is actually doing with the data packets?

The MStG (German Act on Waste Management) is generally depicted without any (schematic) internal details because that would be completely irrelevant and not of practical importance for practitioners, especially if they don't even know about the required inputs and outputs or if those inputs and outputs are obvious.

In short, regarding the criticized drawing and, frankly, completely missing the point of the actual, already completed topic:
The technician searching for the electrical fault doesn't really care whether there's a direct or indirect connection there or not. Power goes in, and depending on the decision made by the machine safety system, power also goes out to the safety circuits. And the basic circuit diagram allows for exactly that.
It doesn't matter whether it's using PWM, what frequency, phase shift, etc.
This background information would only be relevant for a trainee if they are using a cheap, non-TrueRMS multimeter and have no prior knowledge of how 5V gate driver circuits are built.

Best regards from Munich!

Hi DBär,
A block diagram of a component, such as the glow plug control unit (STG) shown here, can illustrate two different things.
- Functions (hardware or logic symbols), after which external connections terminate at the input of the module; optionally, a label such as "signal" or "power" may be included.
- Interface configurations: This clearly shows the internal configuration of the connection to the outside and is binding.
Solid lines indicate the latter.
The manufacturer stated one thing here but did another. They should have shown the circuit breaker as an internal block, as was correctly done for the controller. Under no circumstances should they have connected the wires to the grounding points; here, they are explicitly indicated with two dots (= connection!).

hg
Herbert.

I'm not familiar with this control unit, but those used in similar applications...
The widely used PROFIBUS products from Infineon should not be underestimated.
They often have an output status that indicates an open load.
or reports a short circuit. In addition, they protect themselves in the event of...
Overload, short circuit, or overheating can be prevented by disconnecting the load.

See the example in the datasheet.
http://www.infineon.com/dgdl/Infineon-BTS432E2-DS-v01_01-en.pdf?fileId=db3a304326623792012688c5622b6cb7
On page 7 of the PDF, you will find the truth table showing the output status.

Best regards, gnash.