Removing and installing rain and light sensor G397 - vehicles without humidity sender G355 — AUDI
Removing and installing rain and light sensor G397 - vehicles without humidity sender G355 on Audi: 17 steps.
The rain and light sensor G397 on the Audi A6/A7 C7 2011–2018 (4G) without humidity sender is bonded to the windscreen with a silicone pad, and whether it works afterwards depends almost entirely on that pad. The interior mirror comes off, the connector is unplugged and the retaining clip released, then a minute's wait lets the pad soften so the sensor can be turned out without leaving residue. The old pad is cleaned off both windscreen and sensor with cleaning fluid D 009 401 04, and a new pad is centred on the sensor through its protective film, pressed down with no air bubbles. The film stays on until just before fitting; the pad is sprayed with cleaning fluid, the sensor goes into its mounting and the clip is pressed home.
🧭 Before you start
Remove the mirror, unplug the sensor, release and remove the retaining clip, wait for the pad to soften and turn the sensor out. Clean all silicone from windscreen and sensor with the cleaning fluid. Fit a new pad to the sensor through its film, free of bubbles, remove the film just before fitting, spray the pad, set the sensor in its mounting and press the clip on until it clicks.
Fits: Audi A6/A7 C7 (4G, 2011–2018); platform code 4X
- Renewed: silicone pad
Don't miss
- Always renew the silicone pad.
- Wait one minute after releasing the clip so the pad lets go without residue.
- Remove every trace of old silicone from windscreen and sensor.
- No air bubbles between pad and windscreen, or the sensor will not work correctly.
- Press the retaining clip on until it engages audibly.
Written for this job from the workshop steps below · TorqFix editorial.
📋 Procedure
- Remove interior mirror General body repairs, interior68Interior mirror; Removing and installing interior mirror.
- Unplug electrical connector.
- Release catches of retaining clip (arrows) using a small screwdriver.
- Detach retaining clip (2) from mounting (1).
- Wait one minute to allow silicone pad to loosen enough so that it can be removed without leaving residue.
- Loosen rain and light sensor G397(item 3) by turning it back and forth and take it out of mounting.
- Remove silicone pad from windscreen, ensuring that no residue remains. [Note: Renew silicone pad.]
- Clean bonding surface on windscreen with cleaning fluidD 009 401 04.
- Remove silicone pad (2) from sensor (1), ensuring that no residue remains.
- Clean bonding surface on sensor with cleaning fluidD 009 401 04.
- Remove silicone paper (3) from silicone pad (2).
- Transparent protective film (1) remains on silicone pad to assist with installation.
- Using transparent protective film (1) to help you, position silicone pad on sensor (2) so that it is centred.
- Press silicone pad onto sensor (2) through protective film (1), ensuring that no air bubbles are present.
- Remove protective film (1) from silicone pad (2). [Note: To prevent the silicone pad from becoming dirty, do not remove the protective film until just before fitting the pad.]
- Spray complete surface of silicone pad (1) with cleaning fluidD 009 401 04 and insert sensor in mounting.
- ⚠ In order to function correctly, rain and light sensor G397 must be clear and there must be no air bubbles between it and the windscreen. — Press retaining clip onto mounting plate until it engages audibly.
Other AUDI procedures
- Removing and installing toothed belt – Audi · 56 torque figures
- Removing engine – Audi A8 D3 · 41 torque figures
- Removing camshaft timing chain from camshafts – Audi A6/A7 C7 · 38 torque figures
- Installing engine – Audi A8 D4 · 36 torque figures
- Removing and installing camshaft timing chain · 29 torque figures
- Brembo brake caliper (PR 1KF and 2EA)
- Servicing front brakes (PR 1LT)
- Servicing ceramic brakes (PR 1LU)
- Checking operation of electronics in heater control unit J65 and of fresh air and air recirculation flap control motor V154
- Replacing air conditioner compressor pulley (“Denso” make, version “3”)
Who makes these pages, and how
TorqFix was built by a mechanic — after a 2,700 km drive with five roadside repairs that no diagnostic tool could explain.
The figures on this page come from manufacturer workshop documentation and are shown as they are. The page is assembled automatically from that data — it is not written by an AI. The AI works in the chat, where it answers for your specific car. It writes nothing here.
Variants of the same model differ. Cross-check torque against the factory manual for your engine before final tightening.
Seen a figure that does not match your manual? Write to us — we correct it and note when. support@torqfix.com
The story behind TorqFix →Workshop data on this page last updated 20 Sep 2026.