MAN TGX 440: EDC 03780-01 Error at Idle - Possible Causes, New Filters, 380,000KM, MPROP Range

Hello
What could be the reason for the EDC 03780-01 error appearing? Filters new, separator cleaned, mileage 380,000km. I would add that the MPROP at idle is between 8.7% and 10.3.

.

This MProp opening is a bit big.

See if the DBV valve on the rail is leaking
Only this fault code is displayed?

Yes, just this code.

Also pay attention to the pre-filter housing, is it translucent, is there any air bubbles in the fuel.

Measure how much fuel is coming back from the injector overflow return (nominally engine hot 60 ml/min), but 150 ml isn't a tragedy either.
When it's normal, put a tube with a censer on the overpressure valve on the common rail pipe. Remove the plug from the pressure control valve (on the injection pump).
If it fires and goes out, try it twice more. If it doesn't fire at all, then the pump to work on, if it does fire, then measure how much fuel it spills per minute, I can't remember exactly, but something around 400-600ml/min.
If the engine is running and fuel is not coming out of the overpressure valve, then put another one on the return from the injectors, because the pump is giving to the max and if it leaks at the connection to the injection, the whole thing will go into the return of the injectors.
If you have two hoses, a menzies, a cap (one is enough) 20 minutes and you will find the fault, guaranteed.

With so little deviation and an error only at idle, I'd rule out the high-pressure pump.
(20 minutes is drive the car in, raise the cab and if you're still fast, you might have time to glance and think about how to get to the high-pressure rail )

I'm doing it in a D20 in a LionCity bus, where the injection pump is behind the alternators and everything is so packed in, it's poetry. Fact, everything I need is on the table. I won't reveal how I remove and put the plug on the pump, but seriously, if I have everything, it takes me that long after a test drive.

Valve checked and not leaking, after Christmas I will check with these overflows and let you know.

lary_1981 wrote:

Valve checked and not leaking

This is an overflow test - the last TGA I did it normally poured one already at 120 Bar.

Remove the injectors and take them in for inspection.

Exactly, it is best to have the injectors all checked/repaired if the connections are ok.

Could the author please write what helped him? Specifically what he did, because I have the same error and a similar problem, except that with me it shows the following errors:

EDC 03780-01
EDC 03779-01
EDC 00094-02
EDC 03775-02
EDC 03776-01


When the car is switched off, the driver starts it and the errors pop up, as if he would not manually delete the errors, the car will gently choke. He manually deletes the errors on the car's computer, starts and drives, the errors light up, but the car drives normally, has power, the combustion is as it was.

@turnip4, you need to do a diagnostic in your case, start by changing the filters error 0094, check the pressure before the filter, a good workshop needs to check your injectors, plus the pump. Do you have to rev for a long time before it fires, or does it fire right up? 3780 - you can bet on the pump, is there oil in the plug from the injectors?

I am just about to replace the filter
It fires right up.
This plug do you mean the so-called spider?

Yes, it's all about the spider.

There is no oil in the spider, I checked, the filters were very dirty, strange because after 6500 km barely. Today I'm at the service, initial diagnosis that the fuel system pressure is too low. Diagnosis continues and it will be either the injection(s) or the high pressure pump.

I replaced the high pressure pump complete with feed pump as it is the most common cause, it starts to spill filings onto the high pressure pump further onto the injectors. I did not move the injectors and it runs.

Well in my case it came out to be the high pressure pump, and they didn't diagnose the injectors well for me because they said it was 990ms on the pump, and it should have been 1100ms. The injector test was not conclusive as the pump was not giving enough pressure. So it remains to be seen what the injectors are like after replacing the pump.



Pump supply? You mean there is still some small pump before the pump and it is worth replacing it straight away? That a pressure drop of 110 ms is already a reason to replace the pump?

I think this is a case of normal wear and tear. There is still a fuel filter between the low pressure pump and the CP pump which should catch the filings.

I can hardly see it, you have given one test and where are the rest? Pressure parameters? DLS was done? Pump capacity? Overflow? Apart from the errors, nothing is known.

That's all they gave me and said pump to replace. Well nothing, I will go and ask for the rest of the tests.

Just because they didn't give on paper doesn't mean they didn't do it.

I am replacing the pump on Monday, the cost of such a pump approx. 3000 PLN gross. The replacement costs about 450 zł net. After replacing the pump I will repeat the injector test and let you know.

Problem solved, the high pressure pump was replaced. After replacement a test was carried out on the injectors. It turned out that the 2nd injector to be replaced, in the service 1300 zł. Net. Replaced and problem solved.

Bună ziua.
Care a fost rezolvarea la problema cu codul de eroare EDC 03780-01.
Am și eu aceeași problemă la un MAN TGX 480.
Mulțumesc anticipat pentru răspunsuri

Check the injectors and high-pressure pump, the fuel system in general including head leaks. Can be done and drive on. Good mechanic or service.