R230 Central Locking

[ChrisP90]

All was functioning properly with the central locking system until the onset of the cold snap. My SL350 was exposed to the elements for several days and became thoroughly frozen. Subsequently, when attempting to unlock with the key fob, there was no response. Utilised the emergency key to access the vehicle and successfully opened the trunk. The battery was inspected and deemed functional; however, it was charged overnight as a precaution. I suspected a fuse issue, so I removed the fuses related to the central locking system, but they were functioning well. The fuses for these boxes are situated in the engine compartment. Access to the fuses in the fuse box located behind the driver's seat is obstructed due to the central locking mechanism securing the lid of the cubby box. Upon use the key fob, the lights flash as though the vehicle is being locked or unlocked, and the alarm system is simultaneously engaged. Nonetheless, the doors remain unlocked and the side mirrors do not retract.
Do you have any suggestions? Is there a method to access the cubby box located behind the seat to get the fuses? Is there a control module that manages the locking and unlocking of doors?

[ChrisP90]

Inspected the varioroof; it is non-functional. The issue may be linked to the pump in the trunk. Is this fused or does it incorporate a relay? Kindly provide the fuse/relay number and its location.

[MichaelThomas70]

The fuse is located behind the driver's seat.

The pump is likely irreparable. £1k for a new one. They generally get moist from water infiltration in the boot.

[ChrisP90]

I reconstructed and evaluated the pump approximately 12 months ago and encased it in plastic to maintain its dryness; therefore, I anticipate it will be functional. I am awaiting a slight improvement in the weather before commencing the disassembly, as it is quite cold in the North. I have observed that detaching the trim panels on the gearbox tunnel provides access to a mechanism for unlocking the locker lid. Is this accurate? I have detached the trim panel from the front of the locker; nevertheless, access is very limited. If the removal of the gearbox tunnel trim panel is indeed feasible, I will likely pursue that option. The vario roof is also inoperative, which I believe utilises a separate pump situated atop the PSE pump. It appears unusual that both pumps have ceased functioning simultaneously, prompting me to consider a potential issue with the fuse(s) or relay.

[MercedesMan98]

The SL63 AMG is stored for winter, but I recall from the handbook that the roof and windows may deactivate in freezing conditions to prevent seal damage.


Or did I merely fabricate that in my mind?

[MercedesMan98]

The vacuum pump operates the locks and massage seats, while the hydraulic pump controls the roof and trunk.

[ChrisP90]

The issue was the problematic 20-amp fuse located beneath the driver's seat; thank you. I have substituted it and will install a 25-amp fuse in the future as recommended by other members. To get this fuse, I had to open the locker lid, necessitating the application of brute force and a screwdriver. I was unable to access the fuses through any alternative method; removing the trim panel from the front of the locker did not provide sufficient space, as I am a large individual. I also attempted to detach the gearbox tunnel trim panels to ascertain if there was a mechanism to release the lid, as previously mentioned in other sources. There was not! At least, not on a 2003 model SL. I am genuinely astonished that MB developed a system in which the failure of a fuse restricts access to the region required for its replacement. I will be altering the locker locking mechanism to ensure that this does not occur in the future. Thank you to anyone who replied to my post.

[MercedesMan98]

A new pump is likely necessary, as a fuse does not fail without cause. I have one refurbished item available for £700, subject to part number specifications.

[ChrisP90]

I believe it malfunctioned due to being completely frozen; I should have let it to defrost for many hours before to attempting to use it with the remote. I will let a few days to ensure everything is satisfactory. Thank you for your generous offer of a replacement; I will contact you should I require one.

[ChrisP90]

I am experiencing analogous problems with my R230 SL. The vehicle was functioning properly, with the central locking, boot soft shut, and roof operational, until a fuse blew. I replaced the fuse, but it has blown again, and substituting the fuse yields no improvement. Absence of central locking, soft-close trunk, or roof.

The red "boot open" signal is illuminated on the dashboard because the secondary soft closure lock is not engaging. Do we consider this a costly pse issue? Alternatively, a more economical boot locking mechanism