Central locking/key fob fault

[M4td]

Good morning, I have just purchased my first Mercedes. A 2004 w211 320cdi estate, it has some issues. 1. Key fobs do not lock/unlock car. 2. Interior courtesy lights do not operate automatically but do manually. 3. Fuel gauge doesn't work.
Other than that it's a pleasure to drive. Any advice welcome.
Cheers
Mat

 

[kid-jensen]

First step on your diagnosis journey would be to change the batteries in the Key fob. The fact that it starts the car (presumably you would have mentioned that if it didn't!), means the communication between the key and EIS is ok.

The Fuel gauge problem could be anything from a broken wire to a faulty tank sensor or gauge. Time to study the wiring diagram...