I get into my 2013 W221 this morning to go to work, turn on the car and I have a CEL. Torque PRO says it's code U0146 "network gateway A". Resetting codes via Torque Pro doesn't get rid of it.

Nothing about the car isn't working. All systems are fine. Car drives and sounds normal. All computer connected components are functional.

I search this forum and there's nothing on it. You gurus have any ideas before I take to the stealership and get robbed?

 

Well, after getting tumbleweeds here (not mad. ) I took it to my local Benz stealership. I checked in:

"Mr. Morgan, it'll be $165 to diagnose. Is that okay?"

****ing hell...fine. I signed and let them proceed.

After waiting about an hour the service rep came to me and said, "well, we couldn't find anything wrong. We reset the network and it's all clear. We also washed her inside and out. No charge. You're good to go."

O_O

Wow....was not expecting that! I thought I was certainly out the $165 diagnostic, and possibly thousands for new unit(s), fiber or whatever. What a happy ending!!! Kudos to Mercedes Benz of Seattle service crew.

 

I forgot to add for future reference and searches....after leaving work to head to my appointment my dash lit up like a chrismas tree while pulling out of my building garage. Hold brakes weren't working. Turn signals didn't work. parking brake, airbag and other assorted light on. I drove a couple of block, then the lights started disappearing and my turn signals came back. Then the CEL went off! But it came back on so that's when I returned to the dealership for the diagnostic episode I described above.

I hope someone someday finds peace and comfort in this thread when they have the same code and start ****ting themselves.

 

Well ****. It's happening again. I wonder if the CAN bus fuse is blown? The main CAN bus is losing connectivity to all the other CAN buses. HVAC codes....body codes....generic network codes....communication loss to gateway A.

 

The main gateway throws errors and dash behaves like you describe when you have an under voltage condition. Those are common symptoms. They go away as you drive and the battery is getting charge. But it most likely does not hold.

Have the battery load tested. I suspect it will fail the test.

 

I thought precisely that. And yes....the myriad of lights and error messages go away after I drive a bit. But the CEL will remain after a brief restart. I figure that's because that code has to be manually cleared. They said they tested the batteries and said they were fine. I'm going back in the morning. I'll bring this up. Thanks.

 

Do you know how to bring up the battery voltage in the instrument cluster? If not, do this -

Get in the car and close all of the doors. Assuming you have Keyless Go, press it one time with the brake off. Then use the steering wheel to navigate to the Trip menu where you can press up/down to display Trip Odo/MPG/Range/MPH. Hold down "Telephone Answer" button on one side of the steering wheel and at the same time press "OK" on the other side and hold them for about 5 seconds. You should see a new display in the center of your speedometer showing something like "UB:12.3V." Leave the IC menu there, and note the numbers when you first bring up the menu, and after starting the engine at idle, and while driving.

That would help narrow it down, but all of the control modules in these vehicles are very sensitive to undervoltage, and Brake Hold for safety reasons is one of the first things that goes inop when it is slightly under voltage, and if you attempt to engage it, it gives a very vague message.

 

I'm sitting in the dealership now waiting for a new battery. It did it again this morning. Christmas tree....then all clear after about 1/2 mile of driving.

 

For future reference, 24 hour roadside is free in most cases, and they will come to you, your house, where ever and installation is included, and for some reason, it has always been cheaper than buying a battery over the parts counter at the dealership and installing it yourself.

1-800-FOR-MERC

 

I didn't know roadside would do that. That's excellent. Thanks. As for doing it myself....I can't be bothered at this point. Personal preference...no tools.

But an update:

Car has probelms. Brand new battery and still throwing codes about the car network. Systems still acting up. I have to take it back and leave it with them for a few days. I think it's still under warranty. Only has 27,800 miles on it.

 

You should check the in service date of your car. If it's outside of 48 months, then the original warranty has expired. If you purchased it as certified pre-owned from a MB dealer, then it came with an extra 12 months of coverage.

 

So, replaced the battery ($400) and it's still doing it. Took the car back so they could deep dive. Two of the CAN's are intermittently communicating. They say they have to replace both of them. $2,300. :/

I bought an extended warranty for it...so it should be covered. <crossingFingers>

 

If they are adjacent it is usually the wiring.

 

It's been fixed and I got her back.

They ran short circuit tests on everything and found the fuse box and SAN 15 were shorting and screwing everything up. SAN and fuse box were toast. Both replaced and everything is good.

A faulty fuse box...that's a new one for me.

 

Update. Car has been flawless since the repair. (knock on wood)

 

now you' ve done it. prepare your body

 

Hi what is a SAN15 and which fuse box are you describing here. My car is w212 face-lift eclass 2015 reg. It's given me a Christmas tree too. I disconnected the battery and checked all fuses. I don't have power steering or blinkers. Please help.