nsolot

One Key Fob works just fine.

The other Key Fob will lock & unlock the doors, and the car seems to acknowledge when the key is in the ignition, b/c if I open the door, the display beeps and shows "Remove Key", however this key will not budge from position 0.

I did change the batteries in the key.

Is there something else I can try? Otherwise, is there a place I can send they key for repair?

I did search, and the only similar thread I found was from 2007, so I'm hoping there is an updated solution to this problem.

TIA

raymond g-

begin by verifying that the car battery is fully charged at 13vdc. if not, trickle
charge. then try key again. report back

nsolot

I can test voltage with a multimeter. I don't have a trickle charger. Battery in the E320 was replaced a couple years ago.

I am a little curious why the car battery would cause one key not to work, while the other works just fine...

Baby is getting new shoes this morning. Pick her up later today.

raymond g-

dont know. but since we're trying to troubleshoot an electrical/tronic issue, you
don't rule anything out based on assumptions. instead you work from the opposite,
end to verify what you are to rule out.

it is known that 210s can be voltage sensitive. the ignition doesn't depend on
the battery in the key at all. the fact that one Smartkey works doesn't (and the
2nd Smartkey does) can be something as simple as the IR window of the functioning
key be more efficient than the 'bad' key.

so the troubleshooting includes trying to establish whether it is the ignition side
or the key side which is weak.

one also attempts to isolate the least expensive possible....or the most con-
venient) fix first, rather than the pricey one (or most inconvenient) early on.

the mistake many folks make is that they chase symptoms rather than the
cause.

if you test the car battery with a simple VOM, you may not give an accurate
picture of battery health as you are usually measuring static voltage. try
to measure the voltage under load. for example, measure when the car is
at rest. also, measure when the car is cranking.

nsolot

Thanks Raymond,

Makes sense.

After sitting overnight I got a reading of 16.25 V
Motor running 19 V
Turned off motor 17 V

CKonstantin

I would recommend changing your multimeter or at least replacing the battery in it.

Your readings are completely off, when your car is running your voltage should be around 13.5-14.1V depending on load and Rpms, standing voltage between 12.5-13V depending on how long ago you shut down the car and crancking no less then 10.5V(otherwise your battery is on it's way out)...

You can try reading the voltage via the ACC(press the Rest button for a while with the car on, then the driver side Auto button until left side reades 24) your right side T would be your battery voltage at that point(it is about 0.6-0.8 Volts less then actual voltage, eg 13.1-13.3V with the car running at ACC is equal to 14V measured with a multimeter).

Good luck.

nsolot

You Sir, are correct.

I confirmed my m-meter has gone FUBAR and not giving accurate readings with 1.5 & 9 V batteries, and AC wall outlet. All 3 readings are high.

Will post in 2-3 days after I get a new m-meter.

CKonstantin

My buddies, m-meter was doing the same thing(was measuring 100V higher on AC circuit) simply changing the battery resolved the issue.

nsolot

Mine was only reading 150 VAC off a wall outlet. A bit > 2 V on a AAA battery, and 12 V on a 9V.

Low battery was in fact the problem, and a fresh one fixed it. New battery in the m-meter, and the old 9 V battery was was only putting out a little over 4V.

Fresh readings from my E320:

Cold 11.95 V
Running 14.40 V
Turned off, 12.80 V, but every few seconds it would drop 0.01 V


FWIW, this is a BK TOOL KIT 2703A m-meter that I've had for years

CKonstantin

Your voltages do seem to be within the normal range. You are most likely suffering from the coil failure inside the key itself(if I'm not mistaken there is a separate coil inside the key which is detected by the ignition lock, therefor it is possible for the key to unlock the car and yet not being recognized by the ignition lock). Look up the other threads:
https://mbworld.org/forums/e-class-w...emote-key.html