TPM Malfunction

[Kenjibb]

I own a 2015 SLK250d.
The TPM alert indicated that the front left sensor is not being detected.
I anticipated the battery would be depleted.
I visited my local tire shop, where they assessed all four sensors and confirmed their proper functioning.
The vehicle is unable to identify any of the tyre pressure monitoring sensors and seems to be unresponsive.
As if it were calibrating, perhaps?
The orange caution light on the dashboard remains illuminated, first flickering at startup and then becoming steady.
Do you have any suggestions or recommendations for a path forward?
Thank you very much.

[AmericaMonster]

They have a lifespan of around 10 years; hence, a 2015 vehicle will evidently need replacements at this time. Testing them is not feasible; a code reader only provides a static voltage, which does not reflect battery life.

Exchange your front wheels and observe whether the issue transfers to the front right. Verify and adjust tire pressure, then reset the TPMS monitor. Drive for several miles and assess the outcome.

[Kenjibb]

Thank you for that information.
Rearranging the front wheels seems to be a prudent strategy, thereafter tracing the malfunction.
It displayed the three additional pressures until they were verified; currently, none are shown.
I anticipated it to commence functioning after a few kilometres.
I may need to drive a greater distance.
I will prioritise this task today before attending to any other obligations.

[Ledgerciao]

Have you attempted to reset the TPMS using the instrument cluster menus? Uncertain if a 2015 vehicle should autonomously recognise new or differently positioned sensors. It is advisable to travel over 3 miles after a reset, which may have been performed by the mechanic. Upon resetting, the cluster menu should provide a message such as "please wait, TPMS initialising."

[AmericaMonster]

If your tires have directional tread, ensure to revert them after the test. 👍

[Kenjibb]

To conclude, I exchanged the front wheels, drove on the freeway, reset the alert, and after 2 miles, all tire pressures displayed accurately.
Success for the time being; however, it seems that the TPM's batteries are nearing depletion, which may have hindered connectivity due to the distance between the transmitter and receiver.
Thank you for your assistance, everyone.