Will an aftermarket grille affect my BMW 4 Series ADAS?

Aftermarket grilles that change the position or angle of the kidney grille surround can shift the radar sensor behind it. If you've fitted a new grille and Active Cruise Control has stopped working, the radar likely needs recalibration. We see this regularly on 4 Series models with black grille conversions.

Is the BMW 4 Series Gran Coupé ADAS the same as the Coupé?

The G22 Coupé and G26 Gran Coupé share the same front sensor hardware — the same radar behind the grille and the same windscreen camera. The Gran Coupé has additional rear parking sensors due to its longer body, which may also need calibration after rear-end repairs. Front calibration pricing and procedure are identical.

My BMW 4 Series shows no error codes but ACC won't engage — do I still need calibration?

Yes. BMW's system can detect minor radar misalignment and silently disable ACC without generating a stored fault code. If Active Cruise Control stopped working after front-end work, a professional calibration with OEM-grade targets often restores it even when the dashboard shows no warnings. Our ADAS error code guide explains how these faults present differently across BMW models.

BMW 4 Series ADAS Calibration — From £199

BMW 4 Series ADAS Calibration

The BMW 4 Series (G22/G23/G26, 2020+) has the largest kidney grille in BMW's non-SUV range – and the long-range radar sensor sits directly behind it. If your 4 Series had a front grille replacement, bumper respray, or even a new grille surround fitted, the radar alignment may have shifted. Active Cruise Control and Front Collision Warning both depend on that single sensor being aimed within fractions of a degree.

ADAS Systems on the BMW 4 Series

The G22 Coupé, G23 Convertible, and G26 Gran Coupé share BMW's CLAR platform with the 5 Series and use identical ADAS sensor hardware:

Front Collision Warning + AEB – forward camera behind the windscreen plus front radar behind the kidney grille. The 4 Series' oversized grille gives the radar more surface area, but the sensor module itself is the same unit used across the CLAR range.
Lane Departure Warning – camera-based lane tracking with steering vibration alerts.
Speed Limit Info – camera-based traffic sign recognition.

Driving Assistant Professional (standard on M Sport, optional on other trims):

Active Cruise Control with Stop & Go – radar-controlled, works down to standstill in traffic.
Lane Change Assistant – side radar sensors behind the rear bumper panels monitor blind spots and enable semi-automated lane changes on motorways.
Parking Assistant Plus – ultrasonic sensors plus Surround View cameras for automated parking.

Previous generation (F32/F33/F36, 2014–2020): Driving Assistant was optional. The F32's smaller grille positioned the radar lower and further recessed. Where fitted, the same calibration principles apply – but many F32 base models were sold without ADAS.

Common ADAS Triggers for the BMW 4 Series

Grille and Bumper Work

The 4 Series' large kidney grille is a common target for customisation – aftermarket grille swaps, black grille surrounds, and front splitter additions. Any work that removes or repositions the grille can shift the radar module behind it. If Active Cruise Control stops engaging after cosmetic grille work, radar calibration is the fix.

After Windscreen Replacement

The forward camera handles Lane Departure Warning, Speed Limit Info, and emergency braking inputs. On the G23 Convertible specifically, the windscreen sits at a slightly different angle to the Coupé and Gran Coupé – technicians account for this during windscreen calibration.

Gran Coupé Rear Sensors

The G26 Gran Coupé's longer rear overhang positions its parking sensors and Surround View cameras further from the rear axle. If you've had rear bumper work on a Gran Coupé with Parking Assistant Plus, the ultrasonic sensors and cameras may need recalibrating.

BMW 4 Series Calibration Pricing

Service	Price
Windscreen Calibration	£199
Radar/Sensor Calibration	£349
Collision Calibration	£349
Full System Reset	£499

Most 4 Series owners contact us after grille or bumper work affecting the front radar – that's our £349 radar calibration, including a diagnostic scan to confirm sensor alignment before and after.

BMW 4 Series ADAS Calibration

Get a Calibration Quote

BMW 4 Series Calibration Cost

Windscreen Calibration

Radar/Sensor Calibration

Collision Calibration

Full System Reset