ChiquitaTinker

Hi, what might be the possible reason for malfunction? No problems w. keys before, driven some +100tkm myself.
Today visited my daughter in the city nearby , everything OK on the way there, when leaving, the "key pocket" does not regognize the key...? Key turns in the pocket but nothing happens with the electronics & ignition.?
Key batties are OK (new), remote door locks func OK. Tried the spare key as well - same result.
Car battery 2-3 yrs old - didn't have multimeter to check the voltage, but interior lights were on at w door open...
Anyway I'm recharging the battery over night.
Just interested if it is possible that recognizion on the car key pocket has some issues..?
Any Information appereciated ...thank you in advance! Cheers..

CaliBenzDriver

you are doing well with what you have.
👏

Charging the main battery is a great idea regardless this car being driven recently. Perfectly good batteries can get drained for many reasons but the way you carefully noted lights were ON and nothing would happen when turning the key make me concerned with Electronic Ignition Switch itself.

This switch is more like a "key position sensor" that instructs the F-SAM where to switch power. No power switching is done inside EIS, it uses couple opto-couplers to sense key position yet it suffers from poor unsoldered connections. 😳


Further suggestions besides charging batt:

• Scan vehicle OBD port for active EIS faults
• Tap gently around the "key pocket" area
• Reboot car by disconnecting batts 10mn

If you get it going... stay in the slow lane in case it goes dark on you while driving until you can get the root cause figured out.

Best wishes for new year.
🤞