From Ross-Tech Wiki
01042 - Control Module; Not Coded
- Malfunction Indicator Light (MIL) active
- Control Module not coded
- Check Control Module Coding
- Cross Reference Control Module Coding with related Control Modules (e.g. for Country or Powertrain Settings)
- When found in Audi A8/S8 (4E): Headlight Aim Control (Adaptive Light), perform Coding.
- When found in VW Passat (3C): Headlight Aim Control, perform Coding.
- In certain cases this code may be stored even after properly coding a module (e.g. VW RNS510). In such cases make sure to use a proper workshop code (WSC), importer and device number. Those have to be non-0 values, so for example 12345-123-12345 should do it.