Skoda Octavia many intermittent short to ground/plus faults

[magical_octopus]

Hello, I own a 2004 Skoda Octavia 1.9 tdi 110hp asv. It currently has 95.000km, and it's been going into limp mode every week or few weeks for already more than a year (it had 60.000km back then). I've already replaced the relay 109, and used an aditive in case of sticking turbo vanes.

These didn't help, until 3 months ago I had a friend open the ECU (038 906 012 HC) and check for bad soldering points. 3 were found, next to the connector (have pictures). Besides the soldering joints for the connector were resoldered just in case. This seemed to have solved the problem, until three days ago, the car is now entering limp mode every time I drive it.

Errors, not all appear at the same time, sometimes not flagged as intermittent:

19459 - Relay for Low-Output Preheating of Coolant (J359) P3003 - Short To Plus- Intermittent
17946 - Fuel Shutoff Solenoid (N109) Open or Short to Ground - Intermittent
18067 - Coolant Fan Control 1 - Short to Plus - Intermittent
17954 - Boost Pressure Regulation Valve (N75) - Short to plus - Intermittent
17957 - Boost Pressure Regulation Valve (N75) - Open or Short to Ground
17659 - Commencement of Injection Valve (N108) - Short to Plus - Intermittent
18065 - A/C System Input/Output - Short to Plus - Intermittent
18027 - Glow PLug Relay (J52) - Open or Short to Ground - Intermittent
16485 - Mass Air Flow Sensor (G70) - Implausible Signal

One time I deleted the errors with the car stopped, and these appeared again, I deleted them again, then they were gone:

17954 - Boost Pressure Regulation Valve (N75) - Short to Plus - Intermittent
17957 - Boost Pressure Regulation Valve (N75) - Open or Short to Ground- Intermittent
17946 - Fuel Shutoff Solenoid (N109) - OPen or Short to Ground

Car runs fine, besides it going into limp mode. When it is on limp mode it makes a strange whisle sound. I've tested some of the components on vagcom, like the N109 in the Output Test, and it turns off the engine. Tests for the N75, N108 on vagcom seem to change the engine sound, so I guess they work.

Is the ECU to be trusted with those errors? A broken wire or wires causing it? Any ideas on how to check? Or could it be a single defective component making the ECU flag so many unrelated errors? Maybe the ECU is still at fault and needs to be replaced?

Any comments are greatly appreciated, many thanks!

 

[magical_octopus]

So I replaced the ECU for one from the scrapyard, got the vag commander 1.4 to get both ECU pins out, and followed the guide http://wiki.ross-tech.com/wiki/index.php/Immobilizer_III_ECU_Swapping and the car seems to be working fine, all power, no errors.

Nonetheless I found out the chip at fault may be Bosch 30344. It turns out to be responsible for some relays and actuators. I read some people replaced it on their ECU with the same symptoms as me, and it worked out. Anyone has tried it?