Rear lighting, locking and a missing controller in the diagnostic scan can form one connected fault report. Water near a SAM makes the history especially important, but it does not tell us which parts remain serviceable.
The reported W164 symptoms
A public MHH Auto thread describes water found around a Mercedes ML W164 rear SAM, followed by a lack of diagnostic access and several failed body functions. Another controller reported missing data from the rear SAM. The visible account does not establish a completed repair. We use it here as an example of a problem description, not as an AXION success story or a verified repair method. Read the original W164 discussion.
Cleaning is not proof of recovery
Tell the assessing garage exactly what was cleaned, disconnected or powered afterwards. A change after cleaning is useful evidence, but it does not by itself identify whether the remaining issue lies in connections, power distribution, communication or the controller. Replacement compatibility and any required configuration also need checking for the actual vehicle.
Prepare a useful SAM enquiry
- Photograph the complete unit label and record where water was found.
- List the functions that fail together and those that still work.
- Save the full scan, including messages in other controllers and any unit that cannot be contacted.
- Describe the leak repair and any corrosion, connector or fuse-box work already completed.
- Keep the original SAM and identify any donor unit separately.
Existing inspection photographs are helpful; there is no need to open or energise a wet unit to prepare an enquiry. If the vehicle has lost required lighting or behaves unpredictably, arrange a suitable inspection or recovery. For postal enquiries, contact AXION first so we can confirm whether a removed module can answer the question or whether vehicle-side investigation is required.
AXION supports owners and independent garages with Mercedes SAM testing and repair assessment. Send your existing report through our repair enquiry form, or call 07440 134303. We will confirm whether the vehicle is needed at our Didcot workshop or whether a removed module is suitable for UK postal assessment.