The owner of this 2006 Audi A4 2.0 TDI had bought the car with a faulty turbocharger. After the turbo was repaired and refitted, the power did not return, but the Check Engine light stayed off. Diagnostics showed that several fault codes had been disabled in the previous ECU file.

AutoChip carried out an in-depth check of the fault memory, live data and logs recorded during a road test. After reviewing the control unit software and correcting the calibration, the car accelerated more confidently during the drive. In the logs, requested and actual boost pressure, turbo geometry operation and airflow appeared to be in agreement.

Injector data raised a concern about cylinder two, so testing all four injectors on a bench was recommended. The video does not show injector removal or repair. The owner also planned to replace the glow plugs; the outcome of that work is not shown.