Eis or Key?

Tiny
JUN841NC
  • MEMBER
  • 2004 MERCEDES BENZ C230
  • 1.8L
  • 4 CYL
  • 2WD
  • MANUAL
  • 230,000 MILES
Good day

I have a 2004 Mb w203 c230k. I have had a fault with the ignition as the key does not turn. Had the eis programmed and also bought a secondhand eis to be programmed. Locksmiths says key is ok and also both eis seems to be fine but I still cannot turn key in ignition to start vehicle. I went on to buy an emulator to bypass the steering lock but this is also not working. Locksmith checked out all 3 components and did a diagnostic scan on ecu with no fault codes. What could be my next step? My battery still new as everything else works on vehicle, radio, lights, alarm. I'm at wits end.
Monday, September 22nd, 2025 AT 9:33 AM

14 Replies

Tiny
KEN L
  • MASTER CERTIFIED MECHANIC
  • 54,872 POSTS
You need to do a CAN scan not a regular EUC scan, here is a video to show you how.

https://youtu.be/u-4syLc-ifQ

Here is how the system works

1. Key sends IR/RF signal to the EIS.
2. EIS authenticates the key.
3. EIS energizes the ESL (steering lock motor) - if ESL doesn’t unlock, the key won’t turn.
4. Once unlocked, the EIS communicates with the ECU and transmission control module to authorize starting.

Can you try moving the steering wheel while trying to turn the key? It sounds lie the front SAM is out, the CAN scan will tell us. Please go over this guide and get back to us.
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Monday, September 22nd, 2025 AT 5:24 PM
Tiny
JUN841NC
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  • 28 POSTS
Good day
I cannot turn key to any position thus making any type of scan impossible. Also steering is locked tried to jiggle while turning key nothing is happening. Is there any other way of diagnosing the Sam?
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Monday, September 22nd, 2025 AT 10:02 PM
Tiny
KEN L
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Unfortunately the key must be on to do a CAN scan. Have you checked all fuses? Also, there is an ignition lock cable that needs to be checked, if the cable is jammed the key worn turn. Check out the images (below). Please let us know what happens.
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-1
Tuesday, September 23rd, 2025 AT 8:09 AM
Tiny
JUN841NC
  • MEMBER
  • 28 POSTS
Hi. Is this cable on manual or automatic vehicles? Where is it located?
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Tuesday, September 23rd, 2025 AT 8:19 AM
Tiny
JUN841NC
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  • 28 POSTS
I have checked all fuses. This is a manual transmission don't think it has this ignition lock cable.
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Tuesday, September 23rd, 2025 AT 8:26 AM
Tiny
KEN L
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My bad, yep I have never seen a manual c230 car. To be clear when you say ignition "eis" this is what you replaced correct?
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Tuesday, September 23rd, 2025 AT 9:07 AM
Tiny
JUN841NC
  • MEMBER
  • 28 POSTS
Yes the 3rd picture is the switch I've had programmed and also bought another one just for safety sake. I also had the keys programmed and checked. Then for an added step I bought an esl bypass emulator. Locksmith says all checks out. Car has no fault codes. Just can't seem to turn key in ignition. I'm at wits end. Was thinking to pull the steering column don't know if that would work. All fuses checks out aswell also checked relays aswell. Still to no avail. Any ideas would be much appreciated.
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Tuesday, September 23rd, 2025 AT 10:00 AM
Tiny
KEN L
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Does the key turn in the module before installation?
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Thursday, September 25th, 2025 AT 9:58 AM
Tiny
JUN841NC
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  • 28 POSTS
No it does not.
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Thursday, September 25th, 2025 AT 10:29 AM
Tiny
KEN L
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With the switch removed do you have power at the red/vlt wire?
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Friday, September 26th, 2025 AT 9:02 AM
Tiny
JUN841NC
  • MEMBER
  • 28 POSTS
Hi. Yes there is power. Probed with a light tester also the emulator lights up when I plug it in so it's not a power issue.
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Friday, September 26th, 2025 AT 9:13 AM
Tiny
KEN L
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Okay, with the module disconnected please check the brown wire for ground. I would use a test light connected to power to run the test.
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Friday, September 26th, 2025 AT 9:22 AM
Tiny
JUN841NC
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Good day was out of town. Which module are you referring to?
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Sunday, September 28th, 2025 AT 11:12 PM
Tiny
KEN L
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The ignition key module.
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Monday, September 29th, 2025 AT 9:31 AM

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