What's with all these lights in rear and doors?
Thread Starter
Junior Member
Joined: Feb 2023
Posts: 27
Likes: 2
GL320 cdi
What's with all these lights in rear and doors?
2007 320 cdi
-I have non working licence plate lights, but they blink when trunk is being opened/closed.
-rear door lights do the same (at least on the left side)
-rear courtesy light blinks as well....some others may do also but too much going on to observe everything. see the list below
All this seem connected somehow, I'd think...and hopefully someone can tell where to look for short/ground etc issue...Any ideas?
Codes from Delphi:
Multifunction (SAM - Rear (Signal Acquisition and Control Module - Rear) - SAMH164 (Signal Acquisition and Control Module - Rear) - MT/AT)
DTC Description
C331 - CAN communication with upper control panel; fault - Intermittent
C335 - CAN; communication fault with control unit AAC pushbutton - Intermittent
C325 - No or incorrect CAN message from control unit Instrument cluster - Intermittent
91C8 - License plate light; left lamp - Control unit; internal fault - Intermittent
91C4 - License plate light; right lamp - Control unit; internal fault - Intermittent
91DE - Left luggage space light - Short circuit to ground - Intermittent
912B - Left Rear Backup Lamp Circuit Failure - Short circuit to positive or open circuit - Intermittent
913B - Tail and parking lamp; left - Short circuit to positive or open circuit - Intermittent
9127 - Left taillamp and rear fog lamp - Short circuit to positive or open circuit - Intermittent
91AA - Door light; Rear left - Short circuit to ground - Permanent
90C4 - Interference suppression filter - Short circuit - Permanent
91E0 - Left luggage space light - Control unit; internal fault - Intermittent
91BC - Door light; Rear right - Control unit; internal fault - Permanent
91CC - Door lock switch, rear door - Permanent
9103 - Left brake light - Short circuit to positive or open circuit - Intermittent
-I have non working licence plate lights, but they blink when trunk is being opened/closed.
-rear door lights do the same (at least on the left side)
-rear courtesy light blinks as well....some others may do also but too much going on to observe everything. see the list below
All this seem connected somehow, I'd think...and hopefully someone can tell where to look for short/ground etc issue...Any ideas?
Codes from Delphi:
Multifunction (SAM - Rear (Signal Acquisition and Control Module - Rear) - SAMH164 (Signal Acquisition and Control Module - Rear) - MT/AT)
DTC Description
C331 - CAN communication with upper control panel; fault - Intermittent
C335 - CAN; communication fault with control unit AAC pushbutton - Intermittent
C325 - No or incorrect CAN message from control unit Instrument cluster - Intermittent
91C8 - License plate light; left lamp - Control unit; internal fault - Intermittent
91C4 - License plate light; right lamp - Control unit; internal fault - Intermittent
91DE - Left luggage space light - Short circuit to ground - Intermittent
912B - Left Rear Backup Lamp Circuit Failure - Short circuit to positive or open circuit - Intermittent
913B - Tail and parking lamp; left - Short circuit to positive or open circuit - Intermittent
9127 - Left taillamp and rear fog lamp - Short circuit to positive or open circuit - Intermittent
91AA - Door light; Rear left - Short circuit to ground - Permanent
90C4 - Interference suppression filter - Short circuit - Permanent
91E0 - Left luggage space light - Control unit; internal fault - Intermittent
91BC - Door light; Rear right - Control unit; internal fault - Permanent
91CC - Door lock switch, rear door - Permanent
9103 - Left brake light - Short circuit to positive or open circuit - Intermittent
Last edited by julahti; Apr 9, 2023 at 02:19 PM.
MBWorld Fanatic!
Joined: Jan 2010
Posts: 3,116
Likes: 782
NGL450 w/EORP, S550
2007 320 cdi
-I have non working licence plate lights, but they blink when trunk is being opened/closed.
-rear door lights do the same (at least on the left side)
-rear courtesy light blinks as well....some others may do also but too much going on to observe everything. see the list below
All this seem connected somehow, I'd think...and hopefully someone can tell where to look for short/ground etc issue...Any ideas?
Codes from Delphi:
Multifunction (SAM - Rear (Signal Acquisition and Control Module - Rear) - SAMH164 (Signal Acquisition and Control Module - Rear) - MT/AT)
DTC Description
C331 - CAN communication with upper control panel; fault - Intermittent
C335 - CAN; communication fault with control unit AAC pushbutton - Intermittent
C325 - No or incorrect CAN message from control unit Instrument cluster - Intermittent
91C8 - License plate light; left lamp - Control unit; internal fault - Intermittent
91C4 - License plate light; right lamp - Control unit; internal fault - Intermittent
91DE - Left luggage space light - Short circuit to ground - Intermittent
912B - Left Rear Backup Lamp Circuit Failure - Short circuit to positive or open circuit - Intermittent
913B - Tail and parking lamp; left - Short circuit to positive or open circuit - Intermittent
9127 - Left taillamp and rear fog lamp - Short circuit to positive or open circuit - Intermittent
91AA - Door light; Rear left - Short circuit to ground - Permanent
90C4 - Interference suppression filter - Short circuit - Permanent
91E0 - Left luggage space light - Control unit; internal fault - Intermittent
91BC - Door light; Rear right - Control unit; internal fault - Permanent
91CC - Door lock switch, rear door - Permanent
9103 - Left brake light - Short circuit to positive or open circuit - Intermittent
-I have non working licence plate lights, but they blink when trunk is being opened/closed.
-rear door lights do the same (at least on the left side)
-rear courtesy light blinks as well....some others may do also but too much going on to observe everything. see the list below
All this seem connected somehow, I'd think...and hopefully someone can tell where to look for short/ground etc issue...Any ideas?
Codes from Delphi:
Multifunction (SAM - Rear (Signal Acquisition and Control Module - Rear) - SAMH164 (Signal Acquisition and Control Module - Rear) - MT/AT)
DTC Description
C331 - CAN communication with upper control panel; fault - Intermittent
C335 - CAN; communication fault with control unit AAC pushbutton - Intermittent
C325 - No or incorrect CAN message from control unit Instrument cluster - Intermittent
91C8 - License plate light; left lamp - Control unit; internal fault - Intermittent
91C4 - License plate light; right lamp - Control unit; internal fault - Intermittent
91DE - Left luggage space light - Short circuit to ground - Intermittent
912B - Left Rear Backup Lamp Circuit Failure - Short circuit to positive or open circuit - Intermittent
913B - Tail and parking lamp; left - Short circuit to positive or open circuit - Intermittent
9127 - Left taillamp and rear fog lamp - Short circuit to positive or open circuit - Intermittent
91AA - Door light; Rear left - Short circuit to ground - Permanent
90C4 - Interference suppression filter - Short circuit - Permanent
91E0 - Left luggage space light - Control unit; internal fault - Intermittent
91BC - Door light; Rear right - Control unit; internal fault - Permanent
91CC - Door lock switch, rear door - Permanent
9103 - Left brake light - Short circuit to positive or open circuit - Intermittent
Thread Starter
Junior Member
Joined: Feb 2023
Posts: 27
Likes: 2
GL320 cdi
Instrument cluster shows that all those rear lights would be out. I have rear lights though.
If I cleart the codes, and then either turn lights of or press brake, I am able to activated DTC:s for left rear lights, all of the bulbs I think.
Could this be an issue inside rear SAM rather than wiring? Are SAM's interchangable without marrying to the new car if I happen to find one to test?
MBWorld Fanatic!
Joined: Jan 2010
Posts: 3,116
Likes: 782
NGL450 w/EORP, S550
It is your Sam, and it usually fails because of internal corrosion. I am already on record as to what causes that.
A new Sam must be married to the car.
a used Sam must be divorced from its current car before being married to yours.
A new Sam must be married to the car.
a used Sam must be divorced from its current car before being married to yours.
Thread Starter
Junior Member
Joined: Feb 2023
Posts: 27
Likes: 2
GL320 cdi
This car just keeps giving...learning new stuff every day 
Found this video
I was wondering why my Delphi was not able to activate rear section lights, but obviously there is no communication to rear SAM. Just like in this video. My light are not totally dead though so I don't know. I think I will open my rear SAM at least just out of interest.
Found this video
I was wondering why my Delphi was not able to activate rear section lights, but obviously there is no communication to rear SAM. Just like in this video. My light are not totally dead though so I don't know. I think I will open my rear SAM at least just out of interest.
