Golf 3 1Z ECU Replacement: Problems & Troubleshooting

I replaced my ...C (part number) control unit with a ...D control unit from an Audi 80. The purpose of this was that the ...D unit had been modified by having its connectors soldered onto it for chip tuning. I received the control unit poorly packaged, loose in a cardboard box. Something inside was rattling, and upon opening it, it turned out that an EEPROM had fallen out of its socket and was bouncing around inside the control unit. I put it back in place and connected the control unit. The engine is running at an idle speed of 1200 RPM and doesn't respond to acceleration; or, after holding the accelerator pedal fully down for 5 seconds, it cuts out. -> Completely unusable.

So, what could be the cause? Is the control unit mechanically defective? Is the control unit not compatible with my engine? Are the tuning chips/maps junk?

Which chip controls what? If I open the control unit like a book and the connector is on the left, which chip controls the charger or pump – is it located at the top or bottom? Could I damage something if I were to swap the chips or use chips with incompatible specifications?

"Thank you."
alex

It seems the 021D simply doesn't work well with the Golf.

especially since it's showing up as "021C" in VCDS (VAG-COM)?? How is that possible?


Control unit part number: 028 906 021 C.
Component or version: 1.9L R4 EDC SG D60.
Software coding: 00000
Workshop Code: WSC 00000
5 errors found:
00553 - Air mass sensor (G70)
28-10 - Short circuit after positive voltage - Interrupted.
00777 - Throttle position sensor (G79).
27-00 - implausible signal.
65535 - Control unit defective.
00-00 - -
00539 - Fuel temperature sensor (G81)
30-10 - Interruption / Short circuit after positive voltage - Interrupted.
00741 - Brake pedal monitoring.
27-10 - implausible signal - interrupted.

Data read from the measurement blocks:

coolant temperature -0.9°C
intake air temperature -7.2°C
Fuel temperature: 0.7°C.

The coolant temperature was 44 degrees Celsius at the other control unit.

and here from 021C:
Control unit part number: 028 906 021 C.
Component or version: 1.9L R4 EDC SG D60.
Software coding: 00000
Workshop Code: WSC 00000
No error code found.

How is that possible?

Quote:

especially since it shows up as 021C in the VCDS (VAG-COM) software?? how does that happen??

There was a "super tuner" involved, and they put in the wrong memory modules...
I've experienced that before too; the customer's car was running terribly. The chip tuning came from eBay.

Best regards, Rainer.

Assuming the correct EEPROMs or calibration data are used, would the engine control unit (ECU) function properly?