Eberspächer Control Unit Malfunction: Is it Normal?

Hello fellow DIY enthusiasts,

After I have now overcome the problems with the NW setting.
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.
The Bora has come up with something new to keep things interesting for me.

The auxiliary heater is not starting, despite numerous attempts (with the engine running and with the engine off).

I took it to a Bosch service center - the diagnosis was a faulty control unit.

The mechanic explained (after removing the heating system and working in the testing chamber for some time).
'The auxiliary heater is reporting a glow plug fault, but even after I install a new glow plug, the error message still appears.'
'The solution is to replace the control unit.'

I have requested a quote for the replacement part and will follow up again.

However, the circumstances surrounding the diagnosis have made me somewhat suspicious in retrospect.

It could certainly be as described, but the workshop was completely empty, and if I were an underutilized workshop, I wouldn't think of trying to get more work.
'Then I would also be misleading a customer by selling them a faulty product in a sealed box, where they have hardly any chance to check it, even if they take the defective part home after the replacement.'

Therefore:
Has anyone experienced a similar defect with an Eberspächer D4WSC, or heard of such issues?

Do you think my doubts are unfounded (which I actually hope they are, because the service was very friendly and the mechanic seemed competent during the disassembly)?


Best regards,
herwig

Have the fuses for the auxiliary heater been checked ?

My D4WSC has three fuses, and one of them is, as far as I know, for the glow plug. However, I'm not 100% sure, I would need to check that.
I'm not sure if a blown fuse would trigger an error message, but that would be the first place I would start looking.
Did you actually see the error code yourself on the diagnostic device? Because if not, I think your skepticism is understandable (I always have similar suspicions with other mechanics, so I always pay very close attention to what they're doing, even if it's just reading out the SH control unit ), even if it's just reading out the SH control unit. A faulty glow plug has code 020 (open circuit) or 021 (short circuit).
SH-STG errors would be: 090, 092, 093, or 097.
Did you or they measure the old glow plug with an ohmmeter? It should have a resistance of approximately 0.9 ohms when intact. I replaced my own glow plug. It's actually not a big deal, just a bit of fiddling, especially if you don't want to remove the SH (Sicherheitswärmetauscher) and disconnect it from the water circuit .

Have the fuses for the auxiliary heater been checked ?

My D4WSC has three fuses, and one of them, as far as I know, is for the glow plug. However, I'm not 100% sure about that; I'd need to check. I'm not sure if a blown fuse would trigger an error message, but that would be the first place I'd start looking.


Now that you mention it, I remember the mechanic mumbled something about fuses that he couldn't find. However, he tested the SH while it was disassembled.


Did you personally see the error code on the diagnostic device? Because if not, I think your skepticism is not entirely unfounded (I always have similar suspicions with other mechanics, so I always pay very close attention to what they're doing, even if it's just reading out the SH control unit ). A faulty glow plug is code 020 (open circuit) or 021 (short circuit).
SH-STG errors would be: 090, 092, 093, or 097.
Did you or they measure the old glow plug with an ohmmeter? It should have a resistance of approximately 0.9 ohms when intact. I replaced my own glow plug. It's actually not a big deal, just a bit of fiddling, especially if you don't want to remove the heat exchanger to disconnect it from the water circuit .

Unfortunately, I wasn't paying close enough attention when he disappeared with the SH in a small room. Also, my knowledge about SH (self-harm) and ways to help oneself has been exactly zero until now - it's quite possible that this will now come back to haunt me.

If my suspicion is correct, enough time has passed for the defect to have partially resolved itself. There will certainly be no more evidence of any wrongdoing.

But you shouldn't give up hope - let's see what the cost estimate will be next week.

Thank you for your suggestions, anyway!

Therefore:
Has anyone experienced a similar defect with an Eberspächer D4WSC, or heard of such issues?


'Yes, it completely fried the control unit three times. No fuses were blown, but the control unit was completely burnt out. When I read the error codes, I got the most bizarre error messages.'

And this was after a complete replacement, and in some cases, after only 1-2 months of operation.

The last D4WSC unit we received was a new model that worked perfectly until the vehicle was sold. The goodwill shown by Eberspächer was also very commendable!

Therefore:
Has anyone experienced a similar defect with an Eberspächer D4WSC, or heard of such issues?


'Yes, it completely fried the control unit three times. No fuses were blown, but the control unit was completely burnt out. When I read the error codes, I got the most bizarre error messages.'

And this was after a new installation, and in some cases, after only 1-2 months of operation.

The last D4WSC replacement unit was a new model that functioned perfectly until the vehicle was sold. The goodwill shown by Eberspächer was also very commendable!

How old was the auxiliary heater when it malfunctioned?

Did you have to negotiate the goodwill arrangement yourself, or did a workshop do it?

And this was after a new installation, and in some cases, after only 1-2 months of operation.


Reading...

No, the Bosch service didn't handle it in my presence, but I also corresponded with Eberspächer myself, as I initially suspected a manufacturing defect from Bosch, which turned out not to be the case.

Hello everyone,

I'm currently diligently reading through the forum as a newbie, and I'd like to say 'hello' to everyone . Kudos to the forum and everyone who has compiled so much knowledge here! I would like to contribute my own part, if possible...

@Herwig,
'Did you manage to fix the problem with your auxiliary heater? I had a similar issue, although not exactly the same. My D4W (which I installed myself in my Golf 2 TD) wouldn't start. I disassembled the auxiliary heater, removed the old glow plug, found it to be defective, and installed a new one. It tried to start, but after a short period, the starting process would stop. The problem was that there was still some air in the fuel line. So I tried again. The same thing happened; after the third attempt, it was over. No reaction at all. I took it to a Bosch technician, who told me that the control unit locks after three unsuccessful start attempts, stores an error code, and can only be reset and made ready to start again by an authorized dealer (Bosch).'

So far, I haven't been able to connect to Bosch because my vehicle doesn't have the standard connectors required for the diagnostic tool.
My question is, has anyone ever worked with the diagnostic bus of an Eberspächer system? Because having a dedicated diagnostic tool for the auxiliary heater would be a nice luxury, and you wouldn't have to go to Bosch every time you need to clear a fault code .

Best regards, Ben.

'@Ben: You're right, the auxiliary heater locks after three failed attempts. However, I think it's a myth that only the Bosch service can fix the lock. There's this method: Turn on the heater --> wait 3 seconds --> remove the fuse --> wait 3 seconds --> replace the fuse --> wait 3 seconds --> turn on the heater --> wait 3 seconds --> remove the fuse --> wait 3 seconds and replace the fuse again.'
I need to check the manual tonight.

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

'Micha'

Hello everyone,

I'm currently diligently reading through the forum as a newbie, and I'd like to say 'hello' to everyone . Kudos to the forum and everyone who has compiled so much knowledge here! I would like to contribute my own part, if possible...

@Herwig,
'Did you manage to fix the problem with your auxiliary heater? I had a similar issue, although not exactly the same. My D4W (which I installed myself in my Golf 2 TD) wouldn't start. I disassembled the auxiliary heater, removed the old glow plug, found it to be defective, and installed a new one. It tried to start, but after a short period, the starting process would stop. The problem was that there was still some air in the fuel line. So I tried again. The same thing happened; after the third attempt, it was over. No reaction at all. I took it to a Bosch technician, who told me that the control unit locks after three unsuccessful start attempts, stores an error code, and can only be reset and made ready to start again by an authorized dealer (Bosch).'

So far, I haven't been able to connect to Bosch because I don't have the standard connectors required to connect the diagnostic device.
My question is, has anyone ever worked with the diagnostic bus of an Eberspächer system? Because having a dedicated diagnostic tool for the auxiliary heater would be a nice luxury, and you wouldn't have to go to Bosch every time you need to clear a fault code .

Best regards, Ben

@Ben

Yes, this forum is great. Without the experts and the willingness to help here, I, as a novice, would have been lost.
I could probably only find refuge by selling my Bora surfboard.

regarding the auxiliary heater:

The control unit was allegedly defective, it was replaced, and the auxiliary heater was reinstalled.
For safety's sake, the glow plugs were also replaced. Since then, it has only been used about 10 times due to the warm weather.
It seems to be working just as reliably as before.

I didn't provide any feedback because Eberspächer wanted to inspect the old control unit after it was sent in.
and I agreed with the Bosch service that I would pay for the materials as soon as Eberspächer made a decision.
whether and how much they will discount the new product. However, there has been radio silence since then - for whatever reason!
As soon as I know something, I'll post it immediately.


Best regards,
herwig

Hello,

@Micha:
Thank you for the tip! I will try it as soon as the auxiliary heater is installed in the Audi. Have you checked again to see if that is the correct order? I need to check how I wired the heater in the first place .

@Herwig:
Okay, I'll patiently wait to see what Eberspächer says. I have to say that Eberspächer has excellent service - even though they didn't want to provide a wiring diagram for the auxiliary heater in the Sprinter . Hopefully, I'll receive a response soon.

Best regards, Ben.

Hi Ben,

'Sorry for the late reply: Yes, I checked. According to the Eberspächer manual I have, the locking mechanism can be released using the timer, the remote control, or a diagnostic tool or customer service software. The 'repair manual' for the heater contains more details (which I unfortunately don't have).'
The order of operations mentioned above works for Webasto. However, I also encountered a similar situation with a friend, where the 'locking' mechanism was either released or not. In my friend's case, the auxiliary heater also stopped working. After following the instructions above, everything started working again.

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

'Micha'

Is it a Webasto or an Eberspächer (from your acquaintance)?

Hi,

My acquaintance has an Eberspächer.

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

'Micha'

Okay, I'm going to try this out today. Eberspächer insists that it's not possible without a diagnostic device, and they wanted to remove the bumper to do it.