A4 B7 Glow Plug Test: Yes or No? Load Check

Good morning.

I had read that TDI engines no longer require preheating when the temperature is above 9-10°C (approximately 48-50°F).
Now, before starting the engine, I had a coolant temperature of 17.6°C, and it's telling me the following:


09:26:47 Block 012: Preheating system.
01010000 Binary value.
1.88 seconds - Preheat time.
11.93 V Supply voltage
17.6°C Coolant temperature (G62)

Is it still glowing?

In the MWB16 system, it tells me within the first minute that the generator load is at 99.6%, then there's a "click" sound and the load drops to 50%.
Is that 99.6% reading normal? I think the clicking sound is the glow plug system shutting off.

Engine: V6 TDI, Model Code: BDG.

Best regards,

Hello,

In newer engines, it is indeed common to have pre-glow or post-glow even at temperatures above +5°C, and this is done to improve exhaust emissions.

Best regards, Rainer.

Okay, thank you very much .
And the generator load comes from the afterglow, right?

If you compare the safety values of the gluing system (a look in the manual will help here) with the power output of the generator, then you will see that the two are not very different.

2 x 60A in the box...
I was almost certain .
Thank you for the quick responses.

Have a nice day.

Steffen

Thank you, likewise!

Rainer already mentioned that afterglow helps improve exhaust quality by promoting faster achievement of cleaner combustion through higher in-cylinder temperatures. With each new emissions standard, the time window has become smaller, during which cold engines have before they must meet the required emission levels after starting.

Many modern engines, after a quick "glow" to establish a base temperature before starting, continue to heat the already running engine with (possibly gradually) reduced glow power for a considerable time using the glow plug system. It is common practice to do this until a certain threshold temperature is reached in the cooling circuit and, if necessary, until a predetermined afterglow time has elapsed. Consequently, a high current draw can still be detected even minutes after the engine start.

Great explanation .
Then I can continue with my LL-Ruheregelung now .
"By the way: Is cylinder 2 the reference cylinder for the V6 TDI BDG engine? It's not listed in the MWB13/14 documentation."

Best regards, Steffen.