Faulty Control Unit? Get it Fixed Now!

Hello everyone,

We build sewer cleaning machines using VW AVM Turbo-Diesel engines.
During the initial startup of the last device, the motor briefly ran.
and turned it off again. I then checked all the wiring.
and no errors found.
I replaced the engine control unit and the immobilizer control unit, and the engine started immediately.
After a day of flawless operation, we are back to the same level, and the engine is running.
It only briefly turns on and then off. I also can't access the control unit via the K-line.
Suspect a problem with the immobilizer control unit.
Could it be that something damaged the control unit?
Why can't I access the control unit?
Whoever knows, knows. Thank you for your help in advance.

Hi,

Try establishing communication directly through the connector plugs of the engine control unit.
Is the engine control unit standard equipment? Everything sounds like it might be due to a wiring issue. What information is typically found on the engine control unit?

Best regards, Rainer.

At least the K-Line between WFS and MSTG is broken (that's why there's no...).
Diagnosis).
The AVM is a modified AHF engine with an EDC15V control unit (e.g., 038906012EE), detuned to 86 horsepower.

Best regards, Micha.

Hello Rainer,

Thank you for the response.
werde versuchen über Can-Bus ins Steuergerät zu kommen. HI've already thought about...
Loose connection suspected, and all power supplies and ground connections have been tested.
But everything is okay, "unfortunately." It's strange because the device worked perfectly for one day.
Due to time constraints (the customer is complaining), I set up a second, identical device.
"It's working perfectly. I then connected the 'defective' engine control unit and immobilizer to this device."
swapped it out, and I'm experiencing the same symptoms as with the first device. So, something must be wrong.
one of the two control units was damaged.

Engine Control Unit (ECU), VW, part number 038 906 012 GS, Diesel, EDC15 VM 5801.
Bosch part number: 0281 011 018.

I'm heading to the customer now, and I'll try to work with the CAN bus.

Quote:

038 906 012 GS

Is that diagnosis done via CAN?

Rainer K. wrote:

Quote: 038 906 012 GS Is that a diagnosis via CAN?

I doubt that! If that's the case, I would like to have the original .

Hello Rainer,

I tried it, but unfortunately, I can't access the diagnostics via CAN.
I have now sent the control unit to a repair shop.

Do you have any idea how something like that could happen, where a control unit...
"The engine is stalling. Could a faulty sensor on the engine be causing the engine control unit (ECU) to malfunction?"
Unfortunately, I cannot translate that word because it is not a valid German word. It might be a typo or a made-up word. Could you please provide the correct word or more context?

The engine is brand new.
-From the beginning, nothing worked with control unit number 1.
-Control unit number 2, which had been working perfectly for a day, is now also defective.

The engine control unit (ECU) is not completely dead; it is signaling an error via the T121/40 (glowing plug indicator is flashing).
make a mistake.

I hope the repair shop can provide us with information about the defect.

We are almost at a loss for what to do.
We used a multimeter to test all the cables, both from and to the motor.
We're not quite ready to risk using a third control unit yet. It's unacceptable that we...
"Did two faulty control units fail one after another???"

Best regards, Mäck.

You should have brought the STG here.

Besides a major wiring error, I doubt that two control units would simply fail at the same time.

Best regards, Rainer.

Hello Rainer K.

After all the extensive troubleshooting with the faulty control units, I finally found some time to share my experiences.

Let's start with the good news: the machine is working again.

After the failure with the first machine, we built a second one. This one is immediately...
run.

The second one started working initially, but stopped functioning after a day.

The third machine exhibited the same symptoms as the first and did not run.

We sent the control units to Hitzing u. Paetzold in Germany for repair, and they presented with different types of damage.

I contacted the Swiss importer to inquire if he was aware of any issues with a bad batch of control units. He responded that he "needed to do some research first." After doing some research, he came to us with two control units and replaced the faulty one. The new units started working immediately, and they are still working after about 3 weeks.

Okay, here's the translation:

"Now, here's the biggest issue. The importer has always claimed that I made a mistake during the wiring process, and that we would have to find the error. He let us search for the problem like fools, and his support was completely nonexistent. And, strangely, after he..."
Suddenly, he showed up, and he didn't mention the wiring issue anymore.

When it came to the costs, he informed my client that I had been seeking his help from the very beginning.
It was rejected, and he would have found the error within a few hours.

A huge mess!

If there's a good alternative to VW's industrial diesel engines, then go for it.

Thank you very much for the answers.

Best regards, Mäck.

Hello Mäck,

"The engine control units are typically very reliable. In my entire career of chip tuning and working on cars, I haven't seen a single defective unit of this type."
Therefore, the issue with the incorrect wiring is quite likely, even though it's painful to admit. It's also possible that the "replacement control units" only have the essential pins connected or deactivated, who knows?

Why didn't you simply ask the control units what's wrong using diagnostics (by connecting to the K-line)? I have the necessary connectors in my storage.

Best regards, Rainer.
PS: Who imports industrial diesel fuel into Switzerland, including AMAG?

Hello Rainer,

The importer is also AMAG.

The problem was that it was no longer possible to access the control unit via the K-line.
coming.
I tried using an original VW diagnostic tool. Also, the company Hitzing u. Paetzold is not...
"It got into the control unit. Everyone I asked was clueless."
I initially looked for the error on my own system, as the probability of it being in the control unit...
The defect appeared to me to be minor.

The Amag likely had background information about a defective series, which is why they...
He suddenly stopped talking about the wiring error. If he had known from the beginning that...
If we had been upfront about it, it would have saved us a lot of work.

That took about one week of work and 3-4 weeks of waiting.

There were a total of three defective control units.

My wiring was demonstrably correct. We made no changes or adjustments to the wiring.

I've done some research, and it appears the control units are likely manufactured in Romania.

We only replaced the control units, and all 3 machines are now running.

You should source the motors directly from Germany; while Amag charges a fee, they also provide services.
but with poor to non-existent service.

Best regards, Mäck.