When a knock-sensor code appears after engine work, the installation history is useful evidence. A component can be electrically connected while its mounting still needs attention. P0325 should prompt a specific inspection plan rather than an automatic ECU order.
The reference includes more than wiring
Ross-Tech’s VAG P0325 / 16709 entry concerns the G61 knock-sensor circuit. Its possible causes include circuit faults, sensor damage, incorrect tightening and controller damage. It calls for the correct tightening specification. Read the technical entry.
That does not make an arbitrary extra turn of the mounting bolt a repair. The exact sensor installation must follow the applicable engine procedure.
Tell the workshop what was disturbed
Include recent engine, intake or harness work, and identify any replacement sensor. Was the warning present before the repair, immediately afterwards or only on a later journey? Keep that timeline separate from assumptions about the cause.
If there is audible engine noise, describe it as well as the scan result. A fault code and a noise report are separate observations; neither should be omitted because the other seems more convincing.
What helps an electronics referral
Ask the garage to provide the original scan, installation findings and any documented circuit checks. An ECU assessment is easier to scope when the sensor and vehicle-side evidence are available. Do not deliberately load an engine to reproduce knocking for a recording.
Send AXION the findings before removing a controller. We welcome UK garage referrals and owner enquiries, with the assessment route agreed for the exact vehicle.
Reviewed September 2026. Use the complete manufacturer-specific fault description and vehicle repair information.