OPEL ISUZU 8971891360 (16267710 / 1.7L EDU) REPAIR SOLUTION

[Tom_x]

Hi Tom_x
Probably missing the 170 volt initial voltage.
The 12 volt holding voltage is working.

Hi
170 volt ok, only on valve output no voltage

[Tom_x]

Someone have schematic for EDU?
What is the best equivalent for FET and power diodes?

regards
Tom

[meser75]

Hello.
I drew the electrical schematic diagram myself.
Not all, but I think enough to make repairs easier.
8971891360 electrical schematic diagram.jpg
Who needs a photo of the board with the numbers of the elements, write to me in private messages.
P.S. Don't forget to click Thanks+Rep.

[ppservis]

Thanks,Best Regards

[djtaotao]

I have a problem on a EDU which has burned T1&T2, now replaced with 2xBUZ91, but now they are getting too hot on bench testing, with a 230V light bulb as a spill valve load and signal generator at pin 22.
Can someone help me?
Thanks!

[djtaotao]

Can somebody confirm that these pins for T1&T2 are connected to the ground? If I make a wire bridge to the ground the EDU is not working and power consumption is increased a lot.

[meser75]

Can somebody confirm that these pins for T1&T2 are connected to the ground? If I make a wire bridge to the ground the EDU is not working and power consumption is increased a lot.

Errors are not excluded in the schematic diagram. Write, I will correct.

[redsuns]

if i understend well the EDU is just plug and play , noneed of some decoding or similar ?

I also have the doubt, have you heard something?

[Pepita]

The EDU is just plug and play. 1000%

[boniing]

I repaired a dozen electronics for the 1.7 DTI engine.
My experience is:
- the vast majority of problems are weak joints at solder joints, heat, vibrations ... it is obligatory to solder all joints again,
- the problem is the voltage stabilizer, housing TO-220, I recommend replacing the old one with a new 7809,
- connect some of the connections with an additional wire, there are pictures on the web,
- I had a problem with el-co 10uF / 35V, be sure to replace them with el-co but the new ones must be resistant to high temperatures,
- bad connection on 220 Ohm resistors, serial connection, SDM, on the board, be sure to solder them again.20210812_151058.jpg20210812_195251.jpg2015-05-28 09.34.43.jpg

[AlexDuGuesclin]

Hello,
Currently I am trying to troubleshoot my father-in-law's Opel Astra.
Some of you are really, really strong.
This forum is a wealth of information.
Thank you all

[RadovanPetkovic]

I had the opportunity when I test the EDU on the desktop, it works properly with the original valve. The car will not start, that is, it will not work. I repaired many computers but I did not have a case like this. When I had problems with about three ICs in the tssop14 case, I gave up because I didn’t know what they were. And I couldn't buy them anywhere. I almost found out what they were and started to download the schematic from the ODU. It is extremely complicated and I am glad that I came across work from my colleague MESER75. A big thank you. I've fixed a few bugs I've noticed and will upgrade in the future. As far as I can see, the part around the 74HC logic circuits and the quadruple comparator is missing .....
I will post these pictures so maybe it will help someone ..... Let's finally get the correct scheme of the complete device

EDU Šema.jpgEdu IC.jpgDonji deo.jpgGornji deo.jpg20211126_111530.jpg

I will try to clarify the operation of the entire device in my own way.
The ECU sends the frequency to the EDU as the valve should open and close. The valve opens easily on Uvpp 12v. But at higher pressures it needs extra help at a higher voltage of 170V. That's why it works properly on my desk and it can't on my car. There is probably no proper voltage increase to 170V. Exactly that part around the 74hc circuit is not working properly, I don't have oscillograms. I am waiting for the ordered items to be replaced. While I'm waiting in part, I'm going to fix the electrical scheme a bit.
T11 via diode D7 turns on 12V to the valve, synchronously to it transistor T17 to the other end of the valve turns on ground. That's how it works for me now, but the T4 should turn on 170V in the T11 clock to help the valve work properly even at high pressures.
In this scheme, I think the oscillator that controls T7 -> T1 and T2 is missing. Most oscillations are made with two or three inverters IC 74HCO4. These oscillations create a voltage of 170V via the Step Upp power supply. I still have to clarify that mystery with the scheme.
Due to poor contacts and high voltage, 5v circuits are damaged.

[RadovanPetkovic]

Let me clarify a bit the operation of the circuit step up, which raises the voltage for example from 12 to 170V as in our case
Attachment 850689
StepUp.jpg
In our case, the elements participating in that circuit are: L2, D3, C8 and T1-T2 in parallel.
Resistor R27 measures voltage drop and current. If it goes out of certain values, the circuit stops working and that is detected on R13 and then on a double comparator or operational amplifier ......

High-power resistors 0.1 0.033 and 0.022 Ohms serve as current sensors and protect the entire circuit. If any of them is damaged or burned. The transistors are also damaged, ie they are short-circuited
I think the T7 gate lacks a source of oscillations as far as I can see. I'll check and we'll know

Useful videos:
https://www.youtube.com/watch?v=Fvdb...electroinektor.
https://www.youtube.com/watch?v=xf4VNJNm_W0&t=15s
https://www.youtube.com/watch?v=uUk5N_2Cuw8&t=2s

[janusz21]

this components sB1 IT IS OFTEN DAMAGED

[RadovanPetkovic]

It's not. While I wait for 74HC02 74HC04 and 74HC08 to arrive. I checked all the semiconductors and comparators. Everything is correct. If by any chance a small SMD resistor burns out, the only thing left is the 74HC circuit. I know for sure if the 74HC04 inverter circuit is not working well. There is no voltage of 170V.