Recently, I bought 2008 Mercedes GL450 with 200K miles, jump started it and brough it home. One owner and dealer maintained. On my way home everything worked fine except it kind of went into a limp mode for a second with dash lights blinking when moved from a red traffic light. I came home cleaned it and found dead squirrel family in the trunk area. I charged the battery, while I opened the dash, center console, to deep clean everything and in the process a lot of nut shells. The battery tested at over 100% but it died over night. I learned that the dash would light up and stay awake 15 to 20 seconds after locking the vehicle. I found auxiliary battery to be in non recoverable condition and replaced it. The infotainment system would not load up maps even though car came with a upgraded CD. So I made a mistake of resetting it without thinking. The radio went out and I kept hearing CD swirling noise. CD changer under dash had CDs that were turning constantly. I took it out removed CDs and cleaned it deeply.

CURRENT PROBLEMS:
I have learned to pull fuse 11 from passenger side panel over night to keep battery strong for next day. Still don't know what causes it.
The limp mode usually comes at traffic lights or when starting from a stop position. The lights blink ABS/ ESP lights up constant, I pull over and vehicle starts to drive normal with a very light audible metallic buzz.
I have noticed fresh oil spots just below where transmission would be (I have not slid to inspect undercarriage yet).
The transmission shift from 1st to 2nd gear is always hesitant but it gets better if I drive car for a bit (warm up tranny responds better).
I bought and replaced the infotainment system with a used one that came with a 2015 upgraded CD. The maps loaded immediately and asked for address then in less than 3 minutes back to CD not loading. Next day at first crank, same thing loaded the asked for address and then CD not loading.

I borrowed iCarsoft MB II meter from my brother and found following code:
There were many stored codes related to Terminal 30 and drop of voltage which I suspected was associated with battery dying few times. The prominent ones are as follow:
P0721 - Output speed sensor circuit range/ performance (generic and pending)
P2006 - Intake manifold runner control stuck closed Bank 1a (generic and current)
9005 - Control unit N70(overhead control panel control unit) was disconnected from tml.30 (current and stored)
91CF - Component E40/1 (rear end door ambient lamp) or the line to the component has a short circuit to positive or open circuit (current and stored)
9115 - Control module AAC is not sending any data (current and stored)
C335 - Event: Control module N22 (ACC [KLA] control and operating unit) is not sending any data (current and stored)
9006 - Terminal 30b: not present / undervoltage supply (storage battery) (current and stored)
I have bought a USED working infotainment system to rule out HDD corruption since the CD is not loading (now it's not even ejecting)

I am definitely not a Benz guru but have rebuilt 1985 CJ-7, 2000 Honda S2000, at least 3 various year BMW R1200RT motorcycles and work on all my cars for most parts. I will appreciate any help here who knows Benz.

Cheers

 

Could be the front / rear SAM.
check for water intrusion / rust,
probably worthwhile to clean both of them.

 

Update on transmission leak, appears to be an ounce of fluid each time I turn on the engine. I strongly suspect the pan seal has failed. It also makes me wonder that if short shifting and P0721 code could be blamed to lowered fluid level?

 

It’s near impossible to diagnose this car with a standard OBD2 tool. You need a bidirectional scan tool that is compatible with DAS/Xentry to get you ground truth. P codes are for Chevys. Mb codes are either stored or stored and current with verbose problem statement attached.

as far as what you’ve got going on I would check for wheel sensor codes in your litany. When these go bad you get ESP errors and grabby ABS at low speed.

Drive long enough with this you may create enough shock loading on the output shaft to create a trans leak.

 

What? No.

P codes are used by every vehicle that uses OBD2, which is pretty much everything. The first letter lets you know what system is at fault.

Depending on the READER used, this will give you the "verbose problem statement attached".

"The first number in the DTC tells you if the code is specific to the vehicle manufacturer or a generic code that applies to all OBD-II systems. The last three numbers tell you specific information on the vehicle system or circuit that is running into trouble. The first of these subsets is the powertrain, or P codes, and is the largest of the four categories. This is followed by network and integration (U), Body (B), and Chassis (C) codes."

 

I was surprised by that P code comment. Quite some time ago, my scanner showed a couple of P codes on my x164, which Max himself identified for me.

 

definitely not a great year for a 7 speed. Really points to the conductor plate speed sensor …possibly.
Look at both the front sam and rear sam areas for wetness.

 

Again, trying to diagnose a Mercedes without a by directional Mercedes compatible scan tool is harder than it needs to be.

 

You are getting two different things mixed up.

Any scanner can read codes, a bi-directional scanner and read codes AND send commands to the systems. Any scanner can read every code a Benz has, even cheap $10 ones, BUT to do anything about those codes, as in resetting things, or changing parameters, that’s when you need a bi directional tool. Two different tools.

you don’t need a bi-directional tool to diagnose a Benz, just if you want to do anything about it.

 

That’s well put

 

After reading all your comments and reading up few more forum discussions, I came across a video ( ) in which the gentleman describes the CAN network in these cars on whiteboard and how to interpret codes to determine the actual fault. So I recorded all codes and kind of break re group to understand it. I will put my 2 cents with my limited understanding but I will definitely need you alls guidance.

Used an iCarsoft MB II reader
0721 is on OBD II as well as in transmission section of Benz code pulled using
U0155 Lost comm with IPC Module

From Benz system codes:
No CAN from A1/ IPC from all these systems: Transmission, AC, ESA (Driver & Passenger), Parktronics, SCM, Rear & Front SAM, OCP & UCP and ESP
as I have mentioned before the speedometer lights up after 15-20 seconds of locking. With all these system complaining about IPC, do you all think it is gone?

Transmission has 0721 Output Speed Signal and No CAN N47-5 (ESP & BAS) and slipping (I think it's from all that leaking fluid, dropping level)

ASSYST: No CAN with Engine Compartment (this one lost me completely)

Parktronics: Fault CAN UCP & CGM

IC itself has no fault code in benz code check and CGM only shows up in Parktronics. Plenty of signs of squirrel family partying in CGM, distribution, rear SAM area but rest of other areas a bit less. I took out the front SAM, cleaned all terminals with rubbing alcohol and installed it back in. I just need to do same with rear SAM.

I'm thinking about these action Items:

1. Clean rear SAM terminals, inspect circuit board (clean if necessary) and then reinstall
2. Check connections to IPC clean install and check for response then replace if same response, probably have to buy a used one from somewhere.
3. Change transmission fluid and reseal the pan. (any pointers, never done on this vehicle before)

Regards.

 

Update to my last post, I took out the A1 instrument cluster again and found it squeaky clean with no dirt or moisture presence as compare to SAM (front & back). Still curious, I disassembled the shell and inspected the circuit board; of course, what appears to be is a micro capacitor has been burst with probably with an overload (see pictures below). The thing is that nothing indicated any intrusion in this device but I suspect that the short circuit caused by moisture in one of SAMs may have pushed an overload in this board. I have ordered a new meter which should arrive today or tomorrow. Now the question arises if the new one will also overload? that is, how to check if the problem still exist which caused the overload on first place or may be it has been cleared with my cleaning of SAMs boards and terminals with rubbing alcohol.




Comment/ Suggestion: Either I need to learn to decrease the size of pictures as I attach them or MBWorld should have that option during attachment!

 

The pictures automatically resize depending the screen you are viewing. So really no need for you to do it, as its done automatically.

 

Happy (early) Thanksgiving you all;

Replacement of Instrument cluster resolved a whole bunch of issues. Leaving behind just following three things:

1. Intake Manifold Tumbler flap; I've learned it is common issue in these models. The plastic triangle cracks at ball joint leaving one side stuck open/ close. I will take out manifold today to inspect. I've positive feeling about this one.
2. ASSYST and ASSYST +; both show Invalid Drive Authorization Data. (not sure if this is from changing IC or Infosystem
3. Infosystem COMAND Module is not loading disk. I have now 2015 which came with the car unit and an update of 2019 disk which came with new (used) infotainment system.

Question: Can I use my iCarsoft MB-II to reprogram these issues? or do I need a different unit with better system?

Any guidance is appreciated.

 

Awesome development, while adjusting small item such as OCP reset and trying to find fault in rear ambient lamp; somewhere in between the COMAND module reset itself and my system started working normal. Working on Intake Manifold Tumbler Flap now which is pain to reach. Anyone knows any shortcut?
And why it takes a week for my post to get approval?

Thank you all.