01520 is associated with the rain and light recognition sensor G397. Ross-Tech lists supply, wiring and central-electronics coding among possible concerns, and notes that unsuitable windscreen or sensor gel arrangements can also cause problems.
Start with what changed
If automatic wipers or lights stopped working after glass replacement, include that in the first enquiry. State whether the original sensor was transferred and whether its mounting or coupling material was replaced. A BCM coding request alone may overlook the physical installation.
Describe manual operation separately from automatic operation. Wipers working on a manual setting and failing only in automatic mode is different evidence from wipers failing entirely. The same distinction applies to the lights.
Ask for signal evidence
The diagnosis should connect the sensor’s supply and reported status with the actual conditions. Keep any relevant measuring-value report and the complete fault wording. A sensor reading that does not respond as expected needs an explanation before the central module is replaced.
AXION can review supported body-electronics enquiries with the vehicle details and glass-work history. Where coding is needed, the correct installed equipment must be established first. Restoring a warning-free scan is only part of the result; the automatic functions should also be checked under suitable conditions.
Arrange an assessment
For BCM and BSI assessment, send the vehicle details and fault report to AXION. We support enquiries from drivers and garages. Workshop, postal and remote options depend on the job and are confirmed before booking.
Technical reference
Read the supporting technical documentation. The referenced design or vehicle application defines its scope; it is not a universal repair procedure.
Related reading
02861 electronic steering-lock faults and a non-starting vehicle. Browse the automotive electronics repair library for other systems and symptoms.