turning off engine, shifting malfunctions - codes, EZS electronic ignition lock N73
this is what's going on with my car, 2010 E350 4matic,
1.won't turn off for several minutes of repeated tries, then finally does. I try the go button and 2 fob keys. This happens randomly, 1-2 times a month for past 6 months.
2.while trying to shift into R or D, from a full stop, will spontaneously shift back to Park. This has happens maybe 3 times in the last 6 months.
3.while driving at a slow roll, it spontaneously shifted from D to Park. This happened only a few times on 1 day, Feb. 8.
the local shop got these codes,
C12100 communication with ESP has a malfunction EZS electronic ignition lock N73
C14600 communication with the central gateway has a malfunction EZS electronic ignition lock N73
a10d00 the power supply is too low KG KEYLESS GO N69/5
Has anyone experienced this, and how was it repaired?
thanks




Not too difficult to inspect
Watch below :
Good luck.....
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Last edited by S-Prihadi; Mar 13, 2025 at 06:37 AM.




this is what's going on with my car, 2010 E350 4matic,
1.won't turn off for several minutes of repeated tries, then finally does. I try the go button and 2 fob keys. This happens randomly, 1-2 times a month for past 6 months.
2.while trying to shift into R or D, from a full stop, will spontaneously shift back to Park. This has happens maybe 3 times in the last 6 months.
3.while driving at a slow roll, it spontaneously shifted from D to Park. This happened only a few times on 1 day, Feb. 8.
the local shop got these codes,
C12100 communication with ESP has a malfunction EZS electronic ignition lock N73
C14600 communication with the central gateway has a malfunction EZS electronic ignition lock N73
a10d00 the power supply is too low KG KEYLESS GO N69/5
Has anyone experienced this, and how was it repaired?
thanks
@CaliBenzDriver and @S-Prihadi , I asked him to do a few tests to verify if his car has the dreaded steering lock. Surya could you please check in WIS if his vehicle has electromechanical steering lock. It is a 2010 with FBS3; security. I cannot believe it does not have it.
The idea of the test was to be certain the EIS is also talking to the ESL (if it exists). Either the EIS is not sending the position 1, or 0 back on return (unlikely), the relay N and R are stuck, or the ECU is not receiving the signal because the CAN is busted
@mbforE350 , if you get the EIS out, you can post photos open before or after, your call.
Here is a link for an inexpensive very good scanner,
https://a.aliexpress.com/_mrxOa9t
It does Benz only
Last edited by JCM_MB; Mar 13, 2025 at 11:35 PM.




This is the smaller sized relay a bit recangular, not the big square one.
https://static.nhtsa.gov/odi/tsbs/20...67510-9999.pdf




i.e. ignition circuit. Named "Chassis circuit 87 relay".
Wonder the side effects if it sitcks




No OK from tranny, engine wont be able to start
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Above is my RHD car, USA LHD will have Relay R close to firewall.
Last edited by S-Prihadi; Mar 14, 2025 at 12:39 AM.
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@CaliBenzDriver and @S-Prihadi , I asked him to do a few tests to verify if his car has the dreaded steering lock. Surya could you please check in WIS if his vehicle has electromechanical steering lock. It is a 2010 with FBS3; security. I cannot believe it does not have it.
The idea of the test was to be certain the EIS is also talking to the ESL (if it exists). Either the EIS is not sending the position 1, or 0 back on return (unlikely), the relay N and R are stuck, or the ECU is not receiving the signal because the CAN is busted
@mbforE350 , if you get the EIS out, you can post photos open before or after, your call.
Here is a link for an inexpensive very good scanner,
https://a.aliexpress.com/_mrxOa9t
It does Benz only
I have answered it somewhere else.
Personally I don't think this is single module... it's a combination.

Last edited by CaliBenzDriver; Mar 14, 2025 at 02:41 AM.
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I have answered it somewhere else.
Personally I don't think this is single module... it's a combination.

What puzzles me is that the car can start w/o issue: EIS sends positions 0, 1, and 2 to the ECU and fires up, but in reverse, 2, 1, 0 fails to complete the shutdown.
and as I scroll down to reply, it jumps on another related thread, N73 - Electronic ignition lock (EZS)? and that must have started a near duplicate conversation.
ANYWAYS.
Back to the column steering anti-theft lock, when I turn the fob key to the AC-on - wait - and crank to start, I can hear more clearly a noise like electronic whirring coming from the rear of the vehicle, than any whisper of a noise at the front,.
I'm guessing that's the fuel pumps activating?
There is no vibration, no sound from the dashboard or steering column, other than the door chimes.
Yesterday, I disconnected the main battery, both positive and negative cables are off, overnight. Today, I'm planning to get to the ignition switch, and see if that white 3-pin piece is needing re-soldering.
Thinking about those codes, and possible explanations...grasping at straws,
Around 115,000 miles on odometer, Sept. 2023, replaced main battery.
Oct. 2023, replaced auxiliary battery, myself.
I didn't bring it in to test or re-set for any codes.
Odometer now is around 130,000 miles.
Could changing out the batteries have brought on codes that didn't erase for 1.5 years, 15,000 miles?
I don't go anywhere for a week at a time.
Could it be possible that the zero to 30F damp winter weather, sitting on concrete driveway-not garaged, could have brought moisture from the ground up, causing the gateway connection or other codes?
There wasn't more than 2" of snow at a given time all winter, and no flooding that I would have been driving through, and definitely no spills inside the car.
I'm wondering, if the EIS problem is fixed, and the main battery is reconnected, if the codes will clear after the driving cycle.
Again, to emphasize, I may not start or drive the car for a week at a time. I heard that some cars can have batteries drain, get wacky problems, just because they aren't driven enough. Is this a known problem?
What's the story with this car, why would there be damp carpeting anyway? rusted floorboards? soaked noise insulation? poor undercarriage design that pockets water?




1 - The panoroof/sunroof has 4 drains: one on each corner. It is very common for car that spend time outdoors sitting that the drains get clogged with leaves, dirt, etc. As the drain fills up with water (in particular with heavy rain or during the winter), the water can reach a level where it starts to leak into the vehicle. Usually you will see a stain on the A or C pillar where the headliner could also start to sag a bit.
2 - On the W212, there are have been several (in the tens), where the windshield sealant starts to give and water starts to leak into the cabin. Winter makes it worse because a little bit of water sips into the sealant area, freezes, expands, increase the gap and the cycle repeats between thaws. Very common issue.
Of course, gravity being our friend, the water tends to accumulate on the bottom of the floor on two particular areas: along where the electrical wiring and the CAN bridge connectors are. Once water gets there, all kind of electric ghosts show up.
Here is a video explaining the water ingestion (notice why I asked you to check the frontSAM)
Here is an example of diagnosing a CAN network issue (Keyless GO this time) -> Notice the CAN bridges on the side of the front seats (both sides), and water ends up on those wiring areas.
Another CAN diagnostic, gear shifting this time
Last edited by JCM_MB; Mar 14, 2025 at 04:16 PM.
I took off the outer screw ring. Several videos show guys using 2 screwdrivers. I find using a needle nose pliers or an inside caliper tool much easier than juggling 2 screwdrivers.
It's STUCK, not just falling out through the hole, behind the dash as several videos show.
Several videos show going to all lengths of removing the dashboard vents and trim, removing the radio, removing the panel above the pedals. USELESS. There is absolutely NO access to the EIS from any of these approaches.
Then I went in through the skirt area of the steering column. As I started to carefully pull the skirt trim back, the plastic cracked in 3 pieces, so I tore that all out. Still, not enough room for a child's hand to get in and get at the box. This guy's demo was more realistic to what I'm encountering. I'm going to give it one more try tomorrow, and then it's dremel cutting time.
Interesting, in the start of this video, he says he's doing this because driving at a slow speed (2-5 mph) and the car spontaneously shifted into park, like mine did.




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I broke it when trying to replace N80 steering column. Brittle plastic with age.
At slow speeds, the tranny will shift into Park automatically if the driver's door is opened. I've only tried it at a standstill, but it's been reported to happen at slow speeds. Maybe a bad door switch could cause this.
If concerned about water intrusion and accumulation, pull up the carpeting and remove the drain hole plugs (grommets) from the floor boards.
Drain plug in place
Drain plug (grommet) removed
At slow speeds, the tranny will shift into Park automatically if the driver's door is opened. I've only tried it at a standstill, but it's been reported to happen at slow speeds. Maybe a bad door switch could cause this.
If concerned about water intrusion and accumulation, pull up the carpeting and remove the drain hole plugs (grommets) from the floor boards.
https://cimg9.ibsrv.net/gimg/www.mbw...de0a37b379.png
Drain plug in place
https://cimg2.ibsrv.net/gimg/www.mbw...35a141d886.png
Drain plug (grommet) removed




Something is causing ISM to go into Park while driving.

Guess what ?
Your tranny longevity may benefit from this repair.
-- Option 1: SCAN your whole chassis for disruption clues.
-- Option 2: If you're in a rush to have parts replaced ask MB Dealer for help or the $3,000. ISM job.
other options require detailed troubleshooting related to solderless EIS and to the CAN-C disruptions.
MB CAN Networking benefits/Need good chassis voltage (ALT/BATT).
Last edited by CaliBenzDriver; Mar 17, 2025 at 03:17 PM.



