Bosch EDC Diesel Control System.

[Dieselpg]

Franz put me onto this forum, and while I've looked in occasionally I haven't felt I've been able to make useful contributions to many of the discussions.
However, in the belief that questions are useful, as they are the trigger to knowledge being released, I have a problem which I need assistance solving.

I'm trying to improve my low level of knowledge about the Bosch EDC Control System, in my case it is used on the BMW M51 style 6 cylinder diesel turbocharged engine.
I have the car Workshop and Electrical manuals, and I do read them!
I have a Diagnostic tool (Rovacom by Blackbox Solutions) that will give me the information the EDC ECU makes available.

I don't understand the significance of all the information, nor do I understand what effect any changes I can make will have on the readings.
When I see a fault message from the ECU, I can't relate it to the readings.
Blackbox are electronic wizards, who can get through the security barriers and talk to ECUs. While they have included a Help system in the Rovacom product, which 'describes' the ECU outputs, I've become convinced, by asking questions, that they know less about diesel engines than I do.

I think my ideal find would be a Bosch trained diesel technician who not only still has all his relevant EDC training notes, but would be willing to share them.

Alternatively, a practising diesel technician, with access to the relevant Bosch Tester (which I know of as 'Green Box', for obvious reasons), and who can let me have sight of the help / explanatory notes that I'm sure must be associated with this.

I will take other (related) offers though

I believe Bosch have a online Technical help system, but as I'm Private rather than Trade this isn't accessible to me.

If it makes a difference, I'm in Derbyshire, UK.

Thankyou for your time.

 

[mattsooty]

Dieselpg,

Whilst I have no experience with the Bosch EDC system per se I do have considerable experience with other Bosch EMS systems.

I have spent a fair amount of time working on EMS calibration and OBD for OEMS, both gasoline & diesel.

Absolutely no problem helping you out, if I can - where in Derbyshire are you???

MS

 

[Dieselpg]

" ... where in Derbyshire are you???"
Matlock / Alfreton.

I've realised that while I know of this system as EDC, this is perhaps more a BMW term.
DDE might be the more appropriate Bosch term.
Cheers.

 

[Dieselpg]

Mattsooty
As an example of where I need to improve my knowledge, I'd like to use the following examples drawn from the Help system of the Diagnostic tool I use.

Help.
Fuel Quantity Feedback (mg/str): Used along with the Current Fuel Quantity and Compared Fuel Quantity values for the EDC ECU to calculate fuelling required compensation values and current load conditions.
In practice.
In my engine, hot, cold, idling, full power, this is always 63.8.

Help.
Current Fuel Quantity (mg/str): This, in conjunction with the Compared Fuel Quantity value, is an indication of any increase in demand which obviously varies with load. Any increased load on the engine such as heated windscreens or air conditioning compressors will need a compensation for the load. When the load is applied, this value should rise above the fuel quantity comparison value momentarily then drop back below to where it normally is.
In practice.
This reflects engine load, warm engine idling, about 11/12. Switch on a high electrical load and it rises to 15/16 for a few seconds, then drops back. As more output is asked of the engine this value rises until under maximum load, across a considerable range of engine speed, this value matches the Compared Fuel Quantity. This Current Fuel Quantity falls to Zero when engine braking is in use, as in a Motorway off slip, or any downhill section where engine braking is being used.

Help.
Compared Fuel Quantity (mg/str): This, in conjunction with the Current Fuel Quantity value, is an indication of any increase in demand which obviously varies with load. Any increased load on the engine such as heated windscreens or air conditioning compressors will need a compensation for the load. This is the non compensated value.
In practice.
Warm idling, about 28, rises under load to a maximum of 49. Does not change when a high electrical load is switched on.

At a steady 30mph (for 25 seconds) the Current is 26, the Compared 35.
At maximum load (full throttle acceleration from 30 to 65mph, 14 seconds) the Current and Compared values match, at 49. Ease the throttle to maintain 65mph (for 25 seconds), and the Current value is 20, while the Compared value stays at 49.

Question 1:
What is the Compared Fuel Quantity value telling me?

Question 2:
From the Current Fuel Quantity help: When the load is applied, this value should rise above the fuel quantity comparison value momentarily then drop back.
In practice the Current and Compared values only match at full throttle, so the sentance from the Help appears to be wrong.
What should it say?

There are other questions, based around fuel timing values, but this post is long enough already

 

[mattsooty]

1/ I would expect that the compared fuel quantity will be from a lookup table which produces an expected fuel calculation for adaption and diagnostic purposes. Although this will be drastically different in some instances the comparisons will only be done in discrete speed/load/time conditions.

2/ Not really sure what it should say to be honest!

MS

 

[Dieselpg]

OK, Thanks anyway.