LH Turn Signal Help!!! Tried everything!
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2007 w211
LH Turn Signal Help!!! Tried everything!
Hi Everyone - I bought my son a 2007 W211 and the LH turn signal does not work. I have scoured the internet and forums for weeks now for a fix and cant find anything else other than SAM issue. I have not found anything and now reaching out for some help! This is the 2007 and later headlamp assembly with just one connector for all bubs. Here is all I have done so far.
1. Replaced bulb
2. Replaced bulb socket holder. Service bulletin and others mention the bulb holder and socket dont make connection. New of both and inspection shows to not be the case. (At least with new headlamp assembly)
3. Traced wires and the grey/black from single assembly connector to SAM looks fine
4. Replaced headlamp assembly.
I confirmed that the bulb and holder are good by placing into the right side. Move to left and no good. I have tried cycling through the ignition, unplugged battery, cleared codes and nothing.
I understand that there is no relay or fuse and the signal is sent from the SAM unit. Before I dig into the SAM to start testing or replace, I wanted to make sure there isnt anything I may have missed. This is the first MB I have owned. I am fairly mechanically inclined but MBs are new to me. Any help here would be greatly appreciated!!! Thank you!
1. Replaced bulb
2. Replaced bulb socket holder. Service bulletin and others mention the bulb holder and socket dont make connection. New of both and inspection shows to not be the case. (At least with new headlamp assembly)
3. Traced wires and the grey/black from single assembly connector to SAM looks fine
4. Replaced headlamp assembly.
I confirmed that the bulb and holder are good by placing into the right side. Move to left and no good. I have tried cycling through the ignition, unplugged battery, cleared codes and nothing.
I understand that there is no relay or fuse and the signal is sent from the SAM unit. Before I dig into the SAM to start testing or replace, I wanted to make sure there isnt anything I may have missed. This is the first MB I have owned. I am fairly mechanically inclined but MBs are new to me. Any help here would be greatly appreciated!!! Thank you!
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Joined: Jun 2024
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E320
Hey Cavtrooper96, Even though you've replaced the bulb, socket, and headlamp assembly, the SAM can sometimes have hidden faults or loose connections that disrupt the signal. Another possibility is a subtle wiring issue where a pin might be corroded or damaged, despite looking fine on the surface. These kinds of problems can be notoriously tricky to diagnose without the right tools. To really zero in on what's going on, I’d suggest running a full system scan with Xentry if you have access to it—it’s a solid choice for Mercedes diagnostics, though it does have a steeper learning curve. If that feels like diving into the deep end, the youcanic full system scanner is my new favorite tool and can perform a comprehensive diagnostic to help identify the exact culprit. Hopefully, with a thorough scan, you can get that LH turn signal shining bright again without turning your garage into a disco!
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From: Colorado
G550
The problem could be equally likely originating with worn contacts on the turn signal stalk. That is, activating the LH turn signal is not activating anything, and if this is the case there likely would be no diagnostic code generated. Without a wiring diagram and courage to tear into the bowels of the car's electrical system, you might need to seek professional help.
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Joined: Oct 2019
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From: Colorado
G550
I should add that some OBDII diagnostic scanners can activate car functions through the OBDII connection. If you have access to such a scanner (or to Xentry) it would be possible to send a command to activate the turn signal. If the turn signal can be activated this way, then the SAM and wiring to the turn signal is OK, and the problem is on the input side of the SAM between it and the turn signal stalk.
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Joined: Sep 2024
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2007 w211
Hey Cavtrooper96, Even though you've replaced the bulb, socket, and headlamp assembly, the SAM can sometimes have hidden faults or loose connections that disrupt the signal. Another possibility is a subtle wiring issue where a pin might be corroded or damaged, despite looking fine on the surface. These kinds of problems can be notoriously tricky to diagnose without the right tools. To really zero in on what's going on, I’d suggest running a full system scan with Xentry if you have access to it—it’s a solid choice for Mercedes diagnostics, though it does have a steeper learning curve. If that feels like diving into the deep end, the youcanic full system scanner is my new favorite tool and can perform a comprehensive diagnostic to help identify the exact culprit. Hopefully, with a thorough scan, you can get that LH turn signal shining bright again without turning your garage into a disco!
Thread Starter
Newbie
Joined: Sep 2024
Posts: 8
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2007 w211
I should add that some OBDII diagnostic scanners can activate car functions through the OBDII connection. If you have access to such a scanner (or to Xentry) it would be possible to send a command to activate the turn signal. If the turn signal can be activated this way, then the SAM and wiring to the turn signal is OK, and the problem is on the input side of the SAM between it and the turn signal stalk.
Is it possible for the SAM to only disrupt the one signal?
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2007 w211
Hi All - Im back. Hoping this additional tidbit helps diagnose. I did get the diagnostic scanner. I was going to use it today but the battery was dead so doing a trickle charge overnight. I did notice today that everything works fine except the LH turn signal just in the headlamp assembly. The side mirror light blinks. However, when we switch the brights on all lights in the LH assembly stop working except for the daytime running lights. Wondering if their may be a short causing this? Im fairly mechanical but electrical is not my forte. Just thought I'd see of anyone had any ideas before I run the scan tomorrow. TIA!
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Thread Starter
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2007 w211
I used the diagnostic scanner and found the below code. I've confirmed signal bulb and socket are good in new left headlight assembly and work on right side but not left. I've checked the Black/Grey wire between connector pin back to where wire comes out below drivers fuses and no signals. All other lights work that come from SAM. No other fault codes when checking front drivers SAM. I can send signal to activate all lights except the left turn signal. What is next step?
1. Should I remove fuses and relay module and check where wire plug into SAM
2. Could it be a CAN issue sending the signal?
3. Could it be that only turn signal is bad in SAM and everything else works?
4. Anything else I can check that may be causing fault or open circuit?
I am almost to the point where I just want to run a wire from E1/e5 pin to the driver side mirror signal and call it a day. Any help would be greatly appreciated.
Component E1e5(Left Turn Signal Lamp) OR Component E2e5(Right Turn Signal Lamp) Is Faulty Or The Lead Has Open Circuit.
1. Should I remove fuses and relay module and check where wire plug into SAM
2. Could it be a CAN issue sending the signal?
3. Could it be that only turn signal is bad in SAM and everything else works?
4. Anything else I can check that may be causing fault or open circuit?
I am almost to the point where I just want to run a wire from E1/e5 pin to the driver side mirror signal and call it a day. Any help would be greatly appreciated.
Component E1e5(Left Turn Signal Lamp) OR Component E2e5(Right Turn Signal Lamp) Is Faulty Or The Lead Has Open Circuit.
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'99 and '05 E55 AMG
Somewhere is a break between the SAM and the ground point.
Pull the socket, connect a multimeter. One contact should be connected to chassis ground. The other contact, when the turn signal is activated, should see a pulsing 12 volts DC. If no connection to ground, follow that wire. If no 12 volts, follow that wire back to the SAM. It is possible and even probable you have poor contact when the bulb is rotated into the socket. If the multimeter shows good ground and good voltage, try a piece of aluminum tape between the bulb contacts and socket contacts. Multiple cases of that on this forum.
Query, is this only the front or the front and rear turn signals? They are on different SAMs. If both front and rear are non-functional, I would look at the turn signal stalk. If only front or rear blinker, look at the SAM and ground connections for that blinker.
One advantage of STAR/Xentry is access to WIS (Workshop Information System) which has the electrical schematics. You'll want a big-screen monitor but it is doable.
Pull the socket, connect a multimeter. One contact should be connected to chassis ground. The other contact, when the turn signal is activated, should see a pulsing 12 volts DC. If no connection to ground, follow that wire. If no 12 volts, follow that wire back to the SAM. It is possible and even probable you have poor contact when the bulb is rotated into the socket. If the multimeter shows good ground and good voltage, try a piece of aluminum tape between the bulb contacts and socket contacts. Multiple cases of that on this forum.
Query, is this only the front or the front and rear turn signals? They are on different SAMs. If both front and rear are non-functional, I would look at the turn signal stalk. If only front or rear blinker, look at the SAM and ground connections for that blinker.
One advantage of STAR/Xentry is access to WIS (Workshop Information System) which has the electrical schematics. You'll want a big-screen monitor but it is doable.
Last edited by bbirdwell; Oct 6, 2024 at 03:57 PM.
Thread Starter
Newbie
Joined: Sep 2024
Posts: 8
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2007 w211
Somewhere is a break between the SAM and the ground point.
Pull the socket, connect a multimeter. One contact should be connected to chassis ground. The other contact, when the turn signal is activated, should see a pulsing 12 volts DC. If no connection to ground, follow that wire. If no 12 volts, follow that wire back to the SAM. It is possible and even probable you have poor contact when the bulb is rotated into the socket. If the multimeter shows good ground and good voltage, try a piece of aluminum tape between the bulb contacts and socket contacts. Multiple cases of that on this forum.
Query, is this only the front or the front and rear turn signals? They are on different SAMs. If both front and rear are non-functional, I would look at the turn signal stalk. If only front or rear blinker, look at the SAM and ground connections for that blinker.
One advantage of STAR/Xentry is access to WIS (Workshop Information System) which has the electrical schematics. You'll want a big-screen monitor but it is doable.
Pull the socket, connect a multimeter. One contact should be connected to chassis ground. The other contact, when the turn signal is activated, should see a pulsing 12 volts DC. If no connection to ground, follow that wire. If no 12 volts, follow that wire back to the SAM. It is possible and even probable you have poor contact when the bulb is rotated into the socket. If the multimeter shows good ground and good voltage, try a piece of aluminum tape between the bulb contacts and socket contacts. Multiple cases of that on this forum.
Query, is this only the front or the front and rear turn signals? They are on different SAMs. If both front and rear are non-functional, I would look at the turn signal stalk. If only front or rear blinker, look at the SAM and ground connections for that blinker.
One advantage of STAR/Xentry is access to WIS (Workshop Information System) which has the electrical schematics. You'll want a big-screen monitor but it is doable.
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Newbie
Joined: Sep 2024
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2007 w211
I had to go out of town unexpectedly so finally got to test the SAM. I ran power to the left front turn signal and the light comes on. I ran that same wire with a pin to the SAM and no light or flashing. I also checked for 12v current with emergency flashers and turn signal but got nothing. This tells me it is the SAM given there are no other light issues for the left turn signal as the back and mirror both flash. What I find odd is that there are zero codes for the front drivers SAM. Is this normal? I do get a code for the rear SAM for the inner rear turn signal so wondering why nothing on the front SAM. Just wanted to check before I bought a used one here locally. The previous owner rigged up some aftermarket blue LEDs so I am sure this may have caused the issue.
I'll start looking at if me Launch Creader will reprogram a SAM. Thanks!
I'll start looking at if me Launch Creader will reprogram a SAM. Thanks!
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2007 w211
Hey Everyone - Thanks again for all the help. Wanted to close this out.
It was the SAM. I found one locally for $30 from same model and year. Swapped out, updated code and boom! Everything works.
It was the SAM. I found one locally for $30 from same model and year. Swapped out, updated code and boom! Everything works.
