Mercedes-Benz Forum banner

1 - 11 of 11 Posts

·
Registered
Joined
·
34 Posts
Discussion Starter #1
Hi,
Visually all external lamps/bulbs are working perfectly fine except 2 reverse white lights. Bulbs are fine but there is no 12v in left and right wire holders. image are attached for a closer look

Without touching anything else, when I start the engine only then I receive the message "Lamp Defective Check Lamps!".
Is this message appearing due to reverse light wiring issue? if yes then my point is that unless I am not putting the car in reverse gear it should not throw this message.

Kindly help me with this error message.

Thanks!
THG
 

·
Registered
Joined
·
31,633 Posts
You'd only get the message as the circuit comes active.

You don't mention where you are (please click user cp and edit details so you can add your location to your profile, as here, often it's useful information when you're seeking assistance) but if you are in a place that has DRL, it's likely to be a city light or headlight, or, anywhere, a brake lamp bulb (since you're likely to be stepping on the brake when you start the car). There is a kind of checklist in the stickies for at least tracing the right circuit, perhaps that will help.

Not seeing any referenced images...sorry.

Good luck.
 

·
Registered
Joined
·
34 Posts
Discussion Starter #3
You'd only get the message as the circuit comes active.

You don't mention where you are (please click user cp and edit details so you can add your location to your profile, as here, often it's useful information when you're seeking assistance) but if you are in a place that has DRL, it's likely to be a city light or headlight, or, anywhere, a brake lamp bulb (since you're likely to be stepping on the brake when you start the car). There is a kind of checklist in the stickies for at least tracing the right circuit, perhaps that will help.

Not seeing any referenced images...sorry.

Good luck.


Hi,
Thanks for your quick reply, I am deployed in a rural area and there is no good workshop near by but as I have mentioned, I have strongly observed that I only sit inside my w210, close the door, did not touch anything or press the brake pedal ( i have done this experiment so many times even without engaging the handbrake), just insert the key and turn it to position-2, (no warning message yet), but when I start the engine the warning message appears, after like 1.5 seconds.

(Please check the images)

Thanks!
THG
 

Attachments

·
Registered
Joined
·
4 Posts
Hi,
Thanks for your quick reply, I am deployed in a rural area and there is no good workshop near by but as I have mentioned, I have strongly observed that I only sit inside my w210, close the door, did not touch anything or press the brake pedal ( i have done this experiment so many times even without engaging the handbrake), just insert the key and turn it to position-2, (no warning message yet), but when I start the engine the warning message appears, after like 1.5 seconds.

(Please check the images)

Thanks!
THG
did you ever find a fix to the issue ? i am currently experiencing exactly the same issue, and im really at a loss at this point
 

·
Premium Member
Joined
·
5,595 Posts
did you ever find a fix to the issue ? i am currently experiencing exactly the same issue, and im really at a loss at this point
What is the year and model of the car ? At what exactly is the problem ? No reverse lights ? Defective lamp message too without pressing / turning on anything ?
 

·
Registered
Joined
·
4 Posts
What is the year and model of the car ? At what exactly is the problem ? No reverse lights ? Defective lamp message too without pressing / turning on anything ?
1998 w210 e300td sedan, the reverse lights dont come on when reversing.. i found a drawing that shows where the plug that goes from the tail-lights to the shifter with the 2 wires ( gray and green/ gray ) .. one is power in, the other one is power out .. i tested them both and they both actually have voltage (12v), was hoping for one of them to be 0 because thats an easy fix .. anyway, then i focus on the rear end, i unplugged the socket from the tail-light that houses the reverse light ( on the trunk lid ) and tested the bulb, bulbholder and the wires going to the connector... the bulb and bulbholder and everything related to it seems to be fine.. but once i took the meter to the wires that are in the plug, it looks like the reverse light wire is still showing 0 .. so i honestly dont know how to keep diagnosing the issue
 

·
Premium Member
Joined
·
5,595 Posts
Hello:)

I believe you are looking at the wrong place... The power to the reverse lights is supplied and monitored by the Illumination Control Module (ICM), aka Light Switch Module, not by the reverse switch in the shifter.

The wires that go to the reverse contacts in the shifter are just sense circuits. Basically ICM send 12V to the switch and if it receives 12V, it deems that the reverse light switch is closed, and then supplies power to the reverse lights.

You need to first check the reverse light (back-up light) fuse at the dash driver side fuse panel which is located just left of the headlight switch. You need to remove the lid and locate the fuse. You should have a fuse listing insert to tell you which fuse is which.
 

·
Registered
Joined
·
4 Posts
Hello:)

I believe you are looking at the wrong place... The power to the reverse lights is supplied and monitored by the Illumination Control Module (ICM), aka Light Switch Module, not by the reverse switch in the shifter.

The wires that go to the reverse contacts in the shifter are just sense circuits. Basically ICM send 12V to the switch and if it receives 12V, it deems that the reverse light switch is closed, and then supplies power to the reverse lights.

You need to first check the reverse light (back-up light) fuse at the dash driver side fuse panel which is located just left of the headlight switch. You need to remove the lid and locate the fuse. You should have a fuse listing insert to tell you which fuse is which.
i did also check all the fuses, theyre fine .. but how do i go about checking if the ICM is in working order ?
 

·
Premium Member
Joined
·
5,595 Posts
You need to check if the wire from reverse switch in the shifter to the ICM is broken.

Does your passenger mirror dip (point downwards) when the mirror switch is selecting the passenger side mirror, and you shift to reverse gear with engine running ?

Also check voltage on the reverse light fuse. Sometimes the holders go bad (corroded / loose) in that area.

Also check the resistance between chassis ground and each of the supply wires where the reverse lamps are. One of the wires may have a short to ground.

Do you have the defective bulb message as soon as you put the gear in reverse ?
 

·
Registered
Joined
·
4 Posts
You need to check if the wire from reverse switch in the shifter to the ICM is broken.

Does your passenger mirror dip (point downwards) when the mirror switch is selecting the passenger side mirror, and you shift to reverse gear with engine running ?

Also check voltage on the reverse light fuse. Sometimes the holders go bad (corroded / loose) in that area.

Also check the resistance between chassis ground and each of the supply wires where the reverse lamps are. One of the wires may have a short to ground.

Do you have the defective bulb message as soon as you put the gear in reverse ?
well the mirror does not dip, the defective bulb message comes on as soon as i turn the ignition on.. dont even have to turn on the lights or put it in reverse.. i try the reverse gear thing when the key is in pos 2.. because im usually alone when diagnosing the issue, so its kind of hard to actually turn the car on and keep running out to check if the lights actually turn on ( obviously )
 

·
Premium Member
Joined
·
5,595 Posts
I assume you did the passenger power window dip test with the passenger mirror is selected at the mirror switch, and with the car is running and gear in reverse.

I suggest you pull the shifter reverse switch connector out and measure the resistance of the reverse switch at the shifter connector when the reverse gear is engaged and when it is not. Voltage measurements are misleading due to bias of the sense circuits. Remember that the reverse switch does not feed the reverse lights, but the ICM does.
 
1 - 11 of 11 Posts
Top