Proper Application Of Chip Protection Films (VERSION 1)

Publication date: 2025-03-18
Reference number: VERSION 1
Supersedes refnos: LI40.15-P-079038

DULL TICKING OR THUMPING IN THE AREA OF THE ENGINE/TWO-MASS FLYWHEEL/TRANSMISSION

TECHNICAL SERVICE BULLETIN

Reference Number(s): LI01.00-P-078172 Version 3, Date of Issue: June 02, 2025

MERCEDES-BENZ:	SL43 (232450), C43 (206087, 206287), GLC43 (254387, 254687)
FUNCTION GROUP:	01.00 - General
REASON FOR CHANGE:	Remedy update

COMPLAINT

Dull thumping noise or ticking noise under the vehicle in the area of the engine/two-mass flywheel/transmission.

Is significantly perceptible at the front right wheel well and can also be faintly heard in the vehicle interior.

ATTACHMENTS

File	Description
seitlich.mp4	Noise audible from the side
Innenraum.mp4	Noise audible in the vehicle interior (quiet)
Unterboden.MOV	Noise under the vehicle

CAUSE

The ticking noise occurs in idle operation in drive program C & S at 780 rpm when the state of charge of the battery is over 65% and the load requirement at the belt-driven starter alternator is simultaneously over 25 Nm.

The load requirement can occur due to a number of auxiliary consumers (e.g. air conditioning system, steering wheel or seat heating, etc.).

REMEDY

Do not replace any parts

Check whether a software update for N127 (PTCU) and N15/15 (transmission) is available.

If no software update is available, create a TIPS case and send to HQ together with the following documents:

Videos of the problem from the exterior and in the vehicle interior
Control unit log, engine N3/10 (ME)
Control unit log, drivetrain N127 (PTCU)

Disclaimer

NOTE: The information contained in this document is intended for use by trained, professional technicians with the knowledge to properly and safely perform diagnosis and repairs on Mercedes-Benz vehicles, using Mercedes-Benz approved tools and equipment. It informs service technicians about conditions that could occur in certain vehicles and provides information that could assist in proper vehicle diagnosis, service, or repair. It does not indicate that a defect is present in any vehicle referenced in this document nor does it imply warranty coverage. DO NOT assume that a symptom or condition, or a described cause of a symptom or condition, affects any particular vehicle or groups of vehicles, or that a described repair applies to any particular vehicle or groups of vehicles. There can be multiple causes resulting in the same or similar symptoms or conditions described in this document, and trained professional service technicians must use their diagnostic skills to make evaluations on a case-by-case basis. The information contained in this document does not guarantee warranty coverage nor does it extend the vehicle's warranty in any way.

SYMPTOMS

Power generation > Engine noise > Noise

Power transmission > Automatic transmission > Noises > Noise

OPERATION NUMBERS/DAMAGE CODES

Op. no.	Operation text	Time	Damage code	Note
			0303236	Damage code for two-mass flywheel - noise