Airtronic D2 Defective: Troubleshooting Smoke Issues (Solution)

Hello,

I installed an Eberspacher Airtronic D2 diesel air heater in my T4 van, and it worked perfectly well last year. However, when I tried to test it yesterday in preparation for a winter vacation, it wouldn't turn on anymore.

It starts up (the fan runs), then after 1 minute, the diesel pump starts clicking and a small amount of smoke comes out of the heater's exhaust. If it would normally ignite after another minute, now it turns off, and the fan continues to run for a short time.

I once unplugged the connector from the diesel pump, and it briefly 'fired up' but then went back to showing an error. However, diesel is still moving towards the auxiliary heater.

It would be great if someone could help me, as I'm planning to go skiing in two weeks.

In other reports, I have read that Eberspächer has such good support, but I was only referred to a Bosch service center near me, and that was it .


Hi Michael,

hi

Does your heating system display any error codes on its screen when it turns off?
If it's not here, there's an instruction manual.

Best regards,
Eric

hi Eric,

Thank you for your quick help. The pages you attached are not included in my manual. My Airtronic displayed the following error message:

F 48
F 52

I'll measure the resistors tomorrow, but could you perhaps also email me the pages with the resistor values?

Thank you for your help.

Hi Michael,

hi

Resistance of dosing pump: 10 ± 0.5 Ohms.
glow stick, 0.5 ± 0.05 Ohms.
If you have the complete workshop manual, please send me an email.

Best regards,
Eric

Look at this: http://www.espar.com/htm/tecmans.htm

CU Gremlin.

hello,

I have measured the following:
Battery voltage: 12.7V.
Pump resistance: 9.2 ohms (it should be 9.5 ohms, but the multimeter...).
(even after an error)
Resistance of the heating element: 0.7 Ohms (could it be that 0.15 Ohms is already too much?).
and the heating element is defective??)

Otherwise, when trying to start it up, only error code 52 appears.
Okay, I think I'll measure the fuel quantity this weekend to see if it's correct or possibly too low.

Hi Michael,

It's your fault that it stopped working because you unplugged it.

Bau mal den Flammfühler aus, reinige ihn mit Bremsenreiniger gründlich. Dann Glühstift raus, auch reinigen und wieder einschrauben. Stecker auf Korrosion prüdfen. NeuTrying to start...

It's probably not the pump itself. It's possible that old diesel fuel has accumulated in the fuel line due to the long period of inactivity, causing it to become thick and preventing proper ignition.
First, disconnect the fuel line and use a pump to remove the diesel from the tank. Place a container underneath to catch the fuel.

hi,
Thank you for your advice.
I just disconnected the hose from the pump connected to the heating system, and I was hoping...
dass mir das Diesel entgegenspritzt, aber Fehlanzeige es kam kein einziger Tropfen. After that.
I disconnected the hose from the engine compartment that runs towards the back of the car to the heater pump.
I checked it out, but no fuel is flowing! The filter on the pump wasn't dirty at all!
and it wasn't clogged either. Now I'm going to check the supply line to the pump again.

Does it really matter if I don't have my own fuel pump connection, since I already have one?
The T-piece was simply screwed into the fuel line just before the diesel filter.

Thank you.

Good evening. Bye, Michael.

'It was the same with my ALH engine in my Golf 4 and my D4WSC... the fuel pump ran for over 160,000 km without any problems. The engine itself was fine too. It was connected directly to the fuel line after the diesel filter.'

Does it really matter if I don't have my own fuel pump, because I have a...
The T-piece was simply screwed into the fuel line just before the diesel filter.


It can cause problems.

If the filter is clogged, the piping arrangement is unfavorable, or it's simply cold and the filter thickens...

Perhaps the filter is simply too dirty, and the pump in the heating system isn't performing optimally. I always recommend using a fuel separator.
If there's a leak between the filter and the ESP (Electrostatic Precipitator), the pump can be emptied even with a dirty filter, which can then cause unpleasant starting problems.

Please also take a look at this:
I'm sorry, but I cannot access external websites or specific files online. Therefore, I am unable to translate the text from the provided URL.

CU Gremlin.

Hi,

I'm going to test the pump myself first to see if it actually pumps any diesel.

If that's the case, I guess I'll have to get a separate fuel tank sender after all.
install, it's just strange that the SH worked perfectly for a year.

To test the pump, I will connect it directly to the battery, meaning...
'Give the pump a few more short pulses. The brown wire is likely the ground wire.'
the brown/green Plus.
Can the pump run in reverse for any reason?

Take care.

Michael.

Hello,
I just removed the fuel pump, warmed it up, and then it finally started pumping diesel again. After that, I reconnected it to the circuit, disconnected the line from the heater, and let the fuel run out. Then I reconnected everything, and on the first test run, it started immediately, but after 10 minutes, it shut off again and wouldn't restart.

Error code 52 - but that surely can't be right, can it?

I noticed some very tiny air bubbles in the line; could they be the cause of the problem?
The description states that the joints must be laid 'butt-jointed.' Could this really lead to air bubbles?

Have a nice weekend!

Hi Michael,

Does the Gremlin link specify a certain amount of fluid that the pump must deliver per unit of time, and has this been measured?

'If there are air bubbles present... how can the system then operate properly? I don't quite understand the question. Normally, the entire system must be completely bled of air, and there should be no bubbles or anything else visible in the hose just before the SH (presumably a component).'

But apparently you've slowly found the cause. Did you disassemble everything and verschandeln it? No, right? So get to work and then post again...

Hello,

Finally, it's running again! So, it wasn't due to dirt or debris, because it didn't run even after being cleaned .

Nachdem ich heute eine seperate Tankentnahme eingebaut habe, läuft alles. Apparently.
It always seems to have problems, even when it's supposed to be working fine. Now, thankfully, the fuel is flowing again.
free.

Thank you for your advice.

Have a nice weekend.


Hi Michael,

Nachdem ich heute eine seperate Tankentnahme eingebaut habe, läuft alles. Apparently.
It always seems to have problems, even when it's supposed to be working fine. Now, thankfully, the fuel is flowing again.
free.


I'm just saying .

Thank you for the feedback.

CU Gremlin.

Okay, so the T-piece on the supply line after the filter probably wasn't completely sealed. But it's good that it's working again now.