G.A.R.F.

Hi i got a REALLY weird problem with my gl320 cdi 4matic
It all starts with an intermittent esp malfunction, Then sometimes the car doesnt starts (With drive to workshop without changing gear on display)
not even crank or pre heat, But after a few minutes everything went back to normal.
Now the car doesnt starts at all and theres a drive to workshop without changing gear, srs restraint sistem malfunction, low range malfunction, airmatic
malfunction on the display in the instrument cluster.

The star diagnosis doesnt recognize a lot of computers when is givin the fault:

CDI4
TRANSMISSION
VG
HAQ
ESP
AB
MRM

The weirdest thing is that suddenly everything gets back to normal and star diagnosis recognize all the computers and erase all falut codes.
(A LOT of communication codes)

I alredy:

Charge battery and tested alternator generation
Check front and rear sam
Changed steering column module n80

I alredy open the ISM module a80 and clean it just in case.

I dont know what to do! I would change the ISM but its very expensive and it seems to me that is a communication problem! Someone can give me a clue?
Thanks in advance!

alx

replace battery and check terminals for good contact

G.A.R.F.

I already test the battery and is in perfect condition, And just in case i borrowed one to discard it

alx

you have either a bad battery/ connection or intermittent ground.

the unrecognized modules are also your biggest power consumers. this usually indicated bad battery/ connections.

check your battery terminals. the x164 and x166 terminals do become lose and cause precisely the behavior you are seeing.

N_Jay

Short somewhere on the CAN bus? (Maybe??)

Fourdiesel

It is not obvious what year your 320 cdi is. That might help. It is also sometimes useful to know what country or state the car is registered in.
(If you are using the correct Mercedes star computer and it is giving you the faults you describe you are already way beyond what most people ask.

G.A.R.F.

Thanks a lot for your answer alx! i already clean all the ground connections i know! But i dont know where are located those x164 and x166, If you could guive me a short guide of where they are i will aprecciate it very much!

G.A.R.F.

Yes, Its a can bus problem. But i dont know if its a faulty ecu or a ground that is giving me all this communication problem

N_Jay

If you go to the EPC you can look at the battery wiring.
It gives you a good idea where to look for the connections.


If you are not getting any other symptoms of a bad connection or ground, (dimming/brightening lights, etc.), I would double check the data lines.
When a lot of modules all show failures at the same time, it is hard to ignore both power (ground), and data connectivity failures.

N_Jay

Or an intermittent short in the wiring??

G.A.R.F.

Thanks a lot N_Jay ill do that! Excuse my ignorance but, What data lines?

N_Jay

The CAN BUSS data lines go to all the controllers.


A short anywhere can affect data communications.

G.A.R.F.

Yes, The weird thing is that its a 2008 and it would be rare that the wiring was defective, I supposed that the problem may be in a bad ground connection! But i dont know where.

N_Jay

6 years or heat, oil, weather, and road grime, and vibration; and you don't think the insulation on a wire can wear through?

G.A.R.F.

The problem is that we are talking about a mercedes! I would expect that from another brand but i know that the quality of those wires are exceptional!

N_Jay

LOL!!!!!!!!!!!


They are well built, but they are not magic.


MB is under the same constraints as everyone else to use more "environmentally sensitive" plastics and such.


Additionally, they are generally low production vehicles so there is less chance of catching every little problem early.


And don't forget, sometimes "Sh*T Happens"

G.A.R.F.

Well you are right thats true, I guess theres nothing more to do than start cheking all wires and grounds!

I just figured that this problem was kind a common but i guess its only mine

rawagah

I appreciate if you lwt me know how was it ended up with you, I have exactly same problem with my S 63 2008 !
some have said Engine control !
I took it to workshop today and will let you know what happened.
cheers

G.A.R.F.

Hi there I already fixed my problem! It was a short circuit in the front left headlight, the cause was water got inside the lens!
Hope that's usefull for you. Anything else I can help you just let me know

fayby

Sorry for digging out an old post. I'm having the exact same problem with my 2011 GL350. I figured it's an electrical issue because the entire steering column is not getting power. May I know how you tracked down to where the short circuit happened?

Thanks

gl450x164

I had this issue happen but it was because i forgot to plug in the connection for the transmission

G.A.R.F.

Hi! No worries this is one of the good things about this forum, we'll that was like 3 years ago so I don't remember exactly but I used the wis asra and start studying how the affected units worked and specially which control units were interconnected with, I inspect every unit that was connected in some way with the affected units (EIS, ME, TCM, ESP) and one of them was the left headlight control unit. All the affected units were connected in some way with this headlight so I pull out the headlight and surprise, it was floated in water. So that was making a short in the CAN with produced me all of that strange symptoms.

Hope it helps.

fayby

Thanks. I'll see if I can track down the problem with the same approach. Appreciated.

08_CDI

Any update or resolution to this? I am experiencing the same issue and i'm starting to go a little crazy.

fayby

yes it turned out to be a short somewhere in my blind spot radars in the rear bumper. Had to replace both of them and a harness.

In other words this happens because the entire CAN bus is not communicating, which then can be result from a short circuit anywhere on anything electrical. Therefore my experience may not apply to you because you may have a short circuit somewhere else.

Hope it helps.