I have a 2011 GL450. I got it going on 3 yrs ago. Suddenly my SRS light came on and my coolant low notification (but this went away a few days later. It wasnt low in any capacity so im still confused about that) a few days later, i noticed my horn wasnt working at the same time i noticed the buttons on my steering wheel stopped working also. I was told it could be that my battery isnt putting out enough voltage so i should replace it soon, however it could also be a fuze. Can i get some opinions and maybe a fuze diagram so i can look into this further?

 

When an appliance does not work, the first thing you do is check whether it is plugged in. When a vehicle has electrical problems, the first thing you do is verify the battery and alternator.

There are fuse charts with the owner's manual. However, it is not likely - fuses blow because something is wrong; they rarely are what is wrong.

I gather from your tone that someone, such as a friend, has tried to advise you, and you are trying to figure out what to do. Take it to a reasonable mechanic and have him check the electrical system.

If you don't find yourself a good independent (non dealership) mechanic, this vehicle will be the ruin of you. The only people that happily own 12 year old GL's are ones who do all the diagnosis and repair themselves. If you are interested in trying that, great, but otherwise I am warning you that you are in way over your head. There is a reason such nice driving vehicles are one tenth the purchase price.

 

Do a quick test of your electrical system.

Hook up a meter to the CENTER of the battery posts, check voltage. Then hook the meter to outside of the battery clamps and read the voltage, should be the same. Then start the vehicle, with the meter hooked up, should not go below 9.5 - 10 VDC. Then when its idling, the voltage should be around 14 or so.

 

Multiple issues occuring simultaneously - "out-of-the-blue" - are typically a sign of a control unit failure/failing. In this case, its likely one of your SAMs (Signal Aquisition Module).

The vast majority of SAM failures on the x164 are due to water intrusion. Check for signs of water pooling in your spare tire well (under the carpet), your battery compartment, and under the driver's seat. The rear SAM is typically the one to fail (located in the spair tire well).

If you find signs of water intrusion, the quicky solution is to dry out the area (including the insulation and the SAM itself) and remove one of the rubber grommets to prevent the water from pooling. Then you can dedicate resources to determine the source of the water intrusion.

Search this forum, the topic has been covered extensively.

gl.