Mercedes Tail Light Problems
To understand more about some common problems of Mercedes Benz tail lights, below are a few questions answered by Experts.
What are the instructions to remove the Mercedes tail light (rear) housing to replace the lamps on an E320?To begin with the trunk trims need to come off first. There is a plastic trim which runs along the rear edge of the trunk, across the trunk catch. It is held in place with a few square plastic rivets. To remove them, the center of the rivets needs to be pried out to allow the plastic trim to be lifted away. From the side trunk panel the round plastic rivets can be removed to replace the lamp. Additionally the plastic trim around the trunk hinge opening need to be unclipped and removed as well. Typically it is easier to go about the replacement with the trim panel removed. I It is also possible to fold it back sufficiently to get a hand into the rear lamp fixtures area. Once removed or folded back the four nuts at the rear panel and one at the side which hold the lamps in position will become visible. The nuts can be removed; the lamps can be pulled out and replaced.
Despite replacing the bulbs of the Mercedes tail lights, why don’t they work though the brake lights do?Normally the Mercedes tail lights are controlled by the rear Signal Acquisition Module (SAM) module. The SAM can be found at the lefts-side of the trunk and are generally available in aftermarket stores. Hence a diagnostic scanner may be required to check the codes in the system. If this is unavailable, home testing can be done by testing the wiring. If the wiring tests fine, the problem is most probably with the module. In case the tail lights were working after the SAM was replaced but stopped after the lights were tested, this would be an indication of short circuiting. The driver for tail lights inside the module could have blown. The wiring between the Mercedes tail light and module can be checked. Most likely the wiring would be fine because they stopped working only once the test procedures started.
Why doesn’t the right Mercedes tail light and the reverse light work on the S500 (1999 model) though bulbs were replaced?To begin the diagnosis of this problem, perform a voltage check at the multi-plug connector to the right rear lamp. When the reverse gear is engaged, there should be approximately 12 volts at the gray/yellow/white wire on terminal 4 of the connector. For the Mercedes tail lights, the approximate voltage should be 12 volts at the gray/yellow/white wire on terminal 6 of the connector. If voltage is present on these terminals, the problem is with the tail lights. If there is no voltage, it could be an issue with either a failure of the exterior or with the wiring of the monitoring unit and the rear lamp connector. In most cases, the problem is usually with the bulb sockets or with the circuit board in the lamp. They need to be inspected for any signs of burning. If there are, it is an indication of poor connections and the sockets can be replaced to check if the problem is resolved.
What is the reason the Mercedes tail light and front running light do not shut off on the R350?Typically a problem with the front signal and acquisition control unit can result in the lamp remaining constantly lit even if the key is off and out of the ignition. A Mercedes SDS machine may be required for the reprogramming and hence the replacement should be carried out by a dealer.
As seen above, the questions related to Mercedes tail lights deal with changing the bulbs, persistent faults, lights remaining on and so on. The Mercedes tail light bulb replacement is quite simple and can be performed by an individual with the help of Experts. However the process may vary based on the model of the Mercedes you drive. Apart from this you could have other questions or doubts which need answers. This is when contacting Experts can be the right step in obtaining more information and taking an informed decision to address the problem.