raverx3m

im having a parade of random electrical codes that im assuming all spawn from that mistery 30g circuit.
and i cant find any reference to it on forums or google.
im gonna list the codes maybe someone can help me figure out whats happening

fault 03 OCP-overhead control panel the interior illumination has a malfunction .there is a short (everything on panel seems to work ok)
974914 the rearinterior illumination has a short circuit to ground or an open circuit
fault 01 rear sam-rear signal acquisition and actuation module
fault 01 dcu-rf-right front door(everything on the door seems to work ok)
fault 05 aac-air conditioning (n22/7) (ac seems to work ok)

a15911 circuit 30G has a malfunction there is a short to ground
b224b98 control unit "rear signal acquisition and actuation module has a malfunction the component or system has overtemperature.
9dd015 the output for the mirror heater has a malfunction there is a short circuit to positive or an open circuit
90a251 the actuator motor to the left blend air flap has a malfunction the component is not programmed
90a951 the actuator motor for the right blend air flap not programmed
90f751 the actuator motor for air flap left defroster vent has a malfunction not programmed
912b51 the actuator motor for the ram air recirculation flap not programmed
917851 the actuator motor for the air distribution flap not programmed
917851air distribution flap not programmed

i have old autel ds708 shop scanner

raverx3m

anyone know?

TimC300

I think its part of the wiring harness all over the car. Based on your fault codes i would be inspecting the rear SAM wiring, check for any faulty wiring. Wonder if there is water damage since the SAM is right below where the trunk will leak.

raverx3m

I work at a tint shop and yes the fuse box in mercedes has been always positioned right under water runoff.
they had this issue since late 90s.
and never fixed it.
where would i find reference to that circuit possibly?
google shows nothing for c300

TimC300

30g is the specific circuit. You have to look at the wiring diagrams for that circuit.

I can find circuit 30g in the headlight diagram for example:

TimC300

I stumbled upon a W204 training manual that mentions Circuit 30g. Doesnt explain much but maybe will give you a lead on what to check. Heres the link to the page of the training manual: https://www.mersec.net/266/on_board_...anagement.html

Mentions it under Exercise.

raverx3m

i checked everything visually and smell test. rear sam smells fresh looks uncorroded. front looks good as well

im assuming that the circuit 30g is the main issue causing all the other seemingly unrelated codes for random things around the car because all those features work fine i ran diagnostic and functional test on the heater flaps and they all move when tested by scanner. but they still throw codes

anyone can take a guess where else i should look?

trigital

All 30G circuits came from Right Fuse module ( the one with Red cover for jump start ). Sometimes this module become defective.

juanmor40

In particular if the car was jumped incorrectly, or sparked while connecting the cables.

CaliBenzDriver

Car shades load upon low voltage... (TimC300)

Is there a chance what you're dealing with is simply low voltage after keeping chassis awake too long without external power supply?
The fix to recharge main battery with a float charger.

raverx3m

looks like a waterline on circuit board in front fuse box module.
previous owner was an absolute idiot and didnt clip the fuse box cover back in so who knows how long the water been getting into it,

im getting codes but all the features work.
where in the front sam would the 30g circuit live? maybe its corroded from moisuture i want to check it out


the battery voltage is good. it has new ish battery