Function requirements, general
Circuit 15R ON
The electronic ignition lock control unit (N73) sends the circuit status of circuit 15 over the interior CAN (CAN B) to the instrument cluster (A1).
Control/warning messages, general
The instrument cluster control/warning messages notify the driver about the current state of the systems installed in the vehicle.
The instrument cluster can issue indicator and warning messages in the following ways:
Optical output of control/warning messages:
Multifunction display (A1p13)
Indicator/warning lamps
Acoustic output of control/warning messages:
Warning buzzer (A1h1)
Turn signal ticking via function check for turn signal lights, acoustic (A1h2)
P54.33-3240-79
Shown on model 218.323 |
A1 | Instrument cluster | A1e38 | Standing lights indicator lamp (as of 01.06.2012) | |
A1e1 | Left turn signal indicator light | A1e41 | Electronic Stability Program warning lamp | |
A1e2 | Right turn signal indicator light | A1e51 | Brake system warning lamp | |
A1e3 | High beam indicator lamp | A1e52 | COLLISION PREVENTION ASSIST warning lamp (with code 258 (COLLISION PREVENTION ASSIST PLUS)) | |
A1e4 | Fuel reserve indicator lamp | A1e54 | Coolant temperature warning lamp | |
A1e7 | Brake fluid and parking brake warning lamp | A1e58 | Engine diagnosis indicator lamp | |
A1e9 | Seat belt warning lamp | A1e59 | DISTRONIC warning lamp (with code 233 (DISTRONIC PLUS)) | |
A1e15 | Supplemental restraint system indicator lamp | A1e66 | Tire pressure monitor warning lamp (with code 475 (Tire pressure monitor)) | |
A1e16 | Preglow indicator lamp (on diesel engine) | A1e67 | Low beam indicator lamp | |
A1e17 | Antilock brake system indicator lamp | A1p8 | Speedometer | |
A1e18 | Rear fog lamp indicator lamp | A1p13 | Multifunction display | |
A1e32 | ESP®/ASR OFF warning lamp |
On vehicles with engine 157, the ESP SPORT indicator lamp (A1e46) is also installed.
The messages shown on the multifunction display are split up according to their level of urgency into four categories:
Category 1 (messages with highest priority):
Category 1 messages refer to states and situations which impair safety, and they take priority over messages with lower priority.
These messages are shown within a maximum period of t = 2 s after they occur, then automatically stored in the message memory and they cannot be acknowledged. When they occur, a brief warning is emitted by the buzzer.
Category 2 (messages with medium priority):
Category 2 messages require the intervention of the driver and appear with a time delay of a maximum of t = 2 s. These messages also include operating feedback. Category 2 messages can be acknowledged. When they occur, a brief warning is emitted by the buzzer.
Category 3 and 4 (messages with low priority):
These messages are menu displays and only serve as information for the driver (e.g. low washer fluid level).
No warning chime is emitted.
Messages with low priority are overlaid by messages with high priority. If several messages with the same priority occur, the message currently displayed is cross-faded by the new message after expiry of the minimum display time.
Function sequence for control/warning messages
The instrument cluster informs the driver about the functionality and status of the installed vehicle systems. Safety-relevant system activities or system malfunctions are shown to the driver in the form of control and warning messages in the instrument cluster.
The following display options are provided for this purpose:
Visual:
Indicator lamps (green, yellow or blue)
Warning lamps (red)
Multifunction display
Acoustic:
Warning buzzer
Turn signal light function check, acoustic
The instrument cluster is connected to the vehicle electronics system via the interior CAN and via the chassis CAN (CAN E) up to 28.02.2013, or up to 01.03.2013 via the chassis CAN 2 (CAN E2).
Vehicles as of 01.03.2013:
The instrument cluster reads requests to issue control and warning messages from control units that are connected to the interior CAN or chassis CAN 2 over the interior CAN or via chassis CAN 2.
Requests to issue control and warning messages from control units that are connected to the diagnostic CAN or chassis CAN 1 (CAN E1), are sent by the front SAM control unit with fuse and relay module (N10/1) via chassis CAN 2 to the instrument cluster.
Requests to issue control and warning messages from control units that are connected to the drive train CAN, are sent by the CDI control unit or the ME-SFI control unit via chassis CAN 1, the front SAM control unit and chassis CAN 2 to the instrument cluster.
Requests to issue control and warning messages from control units that are connected to the suspension FlexRay (Flex E), are sent by the chassis gateway control unit (N93/7) (with code 23P (Driving Assistance package)) over chassis CAN 2 to the instrument cluster.
Vehicles up to 28.02.2013:
The instrument cluster reads requests to issue control and warning messages from control units that are connected to the interior CAN or chassis CAN over the interior CAN or via chassis CAN.
Requests to issue control and warning messages from control units that are connected to the diagnostic CAN (CAN D) or front end CAN (CAN G), are sent by the front SAM control unit via interior CAN to the instrument cluster.
Requests to issue control and warning messages from the DISTRONIC electric controller unit (A89) (for code 233 (DISTRONIC PLUS) or code 237 (Active Blind Spot Assist)) are sent by the video and radar sensor system control unit (N62/2) to the instrument cluster over the chassis CAN.
Requests to issue control and warning messages from control units which are connected to the drive train CAN (CAN C) are sent by the CDI control unit (N3/9) (with diesel engine) or ME-SFI control unit (N3/10) (with gasoline engine) via the chassis CAN to the instrument cluster.
The systems and functions listed in the table below can request the output of control and warning messages via the corresponding control unit.
System / Function | Control unit | Connection | Output | ||
Indicator lamp | Display | Acoustic | |||
ADAPTIVE BRAKE | Electronic Stability Program control unit (N30/4) (without code 233 (DISTRONIC PLUS) or without engine 157) or | CAN E (up to 28.02.2013) | Antilock brake system indicator lamp (A1e17) | | – |
Electronic Stability Program (ESP®) | Electronic Stability Program control unit (N30/4) (without code 233 (DISTRONIC PLUS) or without engine 157) or | CAN E (up to 28.02.2013) | ESP®/ASR OFF warning lamp (A1e32) (Status ESP® On/Off) Electronic Stability Program warning lamp (A1e41) (ESP® system active) | | – |
Adaptive Highbeam Assist (up to 31.08.2014 with code 608 (Adaptive Highbeam Assist)) | Multifunction camera (A40/11) | CAN E (up to 28.02.2013) | – | | – |
Adaptive Highbeam Assist Plus (as of 01.09.2014 with code 628 (Adaptive Highbeam Assist Plus)) | Multifunction camera (A40/11) (with CODE 22P (Lane package)) | CAN E2 | – | | – |
Stereo multifunction camera (A40/13) (with CODE 23P (Driving Assistance package)) | Flex E/CAN E2 | – | | – | |
AIRmatic (with code 489 (AIRmatic) or code 488 (Steel/air suspension)) | AIRmatic control unit (N51/3) | CAN E (up to 28.02.2013) | – | | – |
Active Lane Keeping Assist (up to 31.08.2014 with code 238 (Active Lane Keeping Assist), as of 01.09.2014 with code (23P) Driving Assistance package)) | Multifunction camera (A40/11) (up to 31.08.2014) | CAN E (up to 28.02.2013) | – | | – |
Stereo multifunction camera (A40/13) as of 01.09.2014) | Flex E/CAN E2 | – | | – | |
Active Blind Spot Assist (up to 31.08.2014 with code 237 *Active Blind Spot Assist, as of 01.09.2014 with code (23P) Driving Assistance package)( | Video and radar sensor system control unit (N62/2) (up to 31.08.2014) | CAN E (up to 28.02.2013) | – | – | |
Radar sensors control unit (N62/1) (as of 01.09.2014) | Flex E/CAN E2 | – | – | | |
Trailer recognition (with CODE 550 (Trailer hitch)) | Trailer recognition control unit (N28/1) | CAN B | – | | – |
Audio/Navigation/Communication | Radio (A2) (up to 31.08.2014 with code 523 (Audio 20 CD) or code 510 (Audio 20 CD with CD changer, 6-disk), as of 01.09.2014 with code 505 (Radio 20 NTG5 not navigation capable) or code 522 (Audio 20 radio)) | CAN B | – | | – |
Attention assistance system | Electronic Stability Program control unit (N30/4) (without code 233 (DISTRONIC PLUS) or without engine 157) or | CAN E (up to 28.02.2013) | – | | |
Exterior lights (ABL) | Front SAM control unit with fuse and relay module (N10/1) | CAN B | Low beam indicator lamp (A1e67) | | X |
As of 01.09.2014 | Left headlamp control unit (E1n9) or right headlamp control unit (E2n9) | CAN E2 | – | X | – |
Up to 31.08.2014 | Left xenon light control unit (E1n1) and right xenon light control unit (E2n1) (without code 621 (Intelligent Light System (left-hand traffic) and without code 622 (Intelligent Light System)) | CAN G / CAN B (up to 28.02.2013) | – | | – |
Up to 31.08.2014 | Left headlamp control unit (E1n9) or right headlamp control unit (E2n9) (with code 621 (Intelligent Light System (left-hand traffic)) or code 622 (Intelligent Light System)) | CAN G / CAN B (up to 28.02.2013) | – | | – |
Turn signal confirmation | Front SAM control unit with fuse and relay module (N10/1) | CAN B | Left turn signal indicator lamp (A1e1) | – | – |
Lights on warning | Front SAM control unit with fuse and relay module (N10/1) | CAN B | – | | – |
Automatic transmission control | Intelligent servo module for DIRECT SELECT (A80) or fully integrated transmission control unit (Y3/8n4) | CAN C / CAN E (up to 28.02.2013) | – | | – |
Brake fluid level | Front SAM control unit with fuse and relay module (N10/1) | CAN B | Brake fluid and parking brake warning lamp (A1e7) | | – |
Brake wear indicator | Front SAM control unit with fuse and relay module (N10/1) | CAN B | – | | – |
DISTRONIC (with code 233 (DISTRONIC PLUS)) | DISTRONIC electric controller unit (A89), radar sensors control unit (N62/2) | CAN H / CAN E (up to 28.02.2013) | DISTRONIC warning lamp (A1e59) | – | |
DISTRONIC PLUS with Steer Assist (with code 23P (Driving Assistance package)) | Radar sensors control unit (N62/1) | Flex E/CAN E2 | – | | – |
COLLISION PREVENTION ASSIST (with code 258 (COLLISION PREVENTION ASSIST PLUS)) | COLLISION PREVENTION ASSIST controller unit (A90) | CAN E1/CAN E2 | COLLISION PREVENTION ASSIST warning lamp (A1e52) | – | |
Anti-theft alarm system (ATA) (with CODE 551 (Anti-theft alarm system (ATA))) | Rear SAM control unit with fuse and relay module (N10/2) | CAN B | – | | – |
Parking system (with code 220 (PARKTRONIC) or code 235 (Active Parking Assist with PARKTRONIC)) | Parking system control unit (N62) | CAN E (up to 28.02.2013) | – | | |
Parking brake warning | Front SAM control unit with fuse and relay module (N10/1) | CAN B | Brake fluid and parking brake warning lamp (A1e7) | | – |
Windshield washer system fluid level | Front SAM control unit with fuse and relay module (N10/1) | CAN B | – | | – |
Speed Limit Assist (up to 31.08.2014 with code 513 (Speed Limit Assist)) | Multifunction camera (A40/11) | CAN E (up to 28.02.2013) | – | | – |
Speed warning (with CODE 623 (Gulf States version)) | Instrument cluster (A1) | Internal | – | | |
Seat belt reminder warning | Supplemental Restraint System control unit (N2/10) | CAN E (up to 28.02.2013) | Seat belt warning lamp (A1e9) | – | |
Rear SAM control unit with fuse and relay module (N10/2) | CAN B | ||||
KEYLESS-GO (with CODE 889 (KEYLESS-GO)) | KEYLESS-GO control unit (N69/5) | CAN B | – | | |
Coolant level | Front SAM control unit with fuse and relay module (N10/1) | CAN B | – | | – |
Coolant temperature | CDI control unit (N3/9) or ME-SFI control unit (N3/10) | CAN E (up to 28.02.2013) | Coolant temperature warning lamp (A1e54) | | – |
Steering (with code 213 (Speed-sensitive power steering)) | Electronic Stability Program control unit (N30/4) (without code 233 (DISTRONIC PLUS) or without engine 157) or | CAN E (up to 28.02.2013) | – | | – |
Memory setting (with code 275 (Memory package)) | Driver seat control unit (N32/1) or front passenger seat control unit (N32/2) | CAN B | – | – | |
Engine oil level warning | CDI control unit (N3/9) or ME-SFI control unit (N3/10) | CAN E (up to 28.02.2013) | – | | – |
Engine management | CDI control unit (N3/9) or ME-SFI control unit (N3/10) | CAN E (up to 28.02.2013) | Engine diagnosis indicator lamp (A1e58) | – | – |
Emergency call system (with CODE 348 (Emergency call/assist system) or CODE 359 (TELEAID emergency call system)) | Emergency call system control unit (N123/4) | CAN D (up to 28.02.2013) | – | | – |
Emergency call system (with code 350 (eCall Europe emergency call system)) | Telematics services communications module (N112/2) | CAN D / CAN E2 | - | X | - |
Emergency call system (with code 360 (HERMES UMTS) or code 362 (HERMES LTE)) | HERMES control unit (N112/9) | CAN D / CAN E2 | - | X | - |
PRE-SAFE® | Left front reversible emergency tensioning retractor (A76) or right front reversible emergency tensioning retractor (A76/1) | CAN E (up to 28.02.2013) | Supplemental restraint system indicator lamp (A1e15) | | – |
RACE START (with engine 157) | Transmission mode control unit (N145) | CAN E (up to 28.02.2013) | ESP SPORT indicator lamp (A1e46) | | – |
Tire pressure monitor (with CODE 475 (Tire pressure monitor)) | Tire pressure monitor control unit (N88) | CAN E (up to 28.02.2013) | Tire pressure monitor warning lamp (A1e66) | | – |
Tire pressure loss warning (with CODE 477 (Tire pressure loss warning)) | Electronic Stability Program control unit (N30/4) (without code 233 (DISTRONIC PLUS) or without engine 157) or | CAN E (up to 28.02.2013) | – | | – |
Lane Keeping Assist (up to 31.08.214 with code 476 (Lane Keeping Assist), as of 01.09.2014 with code 22P (Track width package)) | Multifunction camera (A40/11) | CAN E (up to 28.02.2013) | – | | – |
Stationary heater (with CODE 228 (Stationary heater)) | Stationary heater control unit (A6n1) | CAN B | – | | – |
Supplemental restraint system | Supplemental Restraint System control unit (N2/10) | CAN E (up to 28.02.2013) | Supplemental restraint system indicator lamp (A1e15) | | – |
Fuel cap warning (with CODE 494 (USA version)) | CDI control unit (N3/9) or ME-SFI control unit (N3/10) | CAN E (up to 28.02.2013) | Fuel reserve warning light (A1e4) | | – |
Cruise control | Electronic Stability Program control unit (N30/4) (without code 233 (DISTRONIC PLUS) or without engine 157) or | CAN E (up to 28.02.2013) | Segment ring | | |
Blind Spot Assist (with CODE 234 (Blind Spot Assist)) | Left rear bumper intelligent radar sensor (B29/4), right rear bumper intelligent radar sensor (B29/5) | CAN G (up to 28.02.2013) | – | | |
Doors OPEN warning | Rear SAM control unit with fuse and relay module (N10/2), left front door control unit (N69/1) and right front door control unit (N69/2) | CAN B | – | | |
Traffic Sign Assist (as of 01.09.2014 with code 513 (Traffic Sign Assist)) | Multifunction camera (A40/11) (with CODE 22P (Lane package)) | CAN E2 | – | | – |
Preglow indicator (on diesel engine) | CDI control unit (N3/9) | CAN E (up to 28.02.2013) | Preglow indicator lamp (A1e16) | – | – |
Special case of country-dependent seat belt reminder warning:
If, immediately prior to starting a journey or during a journey, a seat belt is detected to be not fitted, the instrument cluster issues a country-specific optical and acoustic seat belt reminder warning.
The Supplemental Restraint System control unit (N2/10) sends information on the status of the driver and front passenger seat belts over the chassis CAN by 28.02.2013 to the instrument cluster or as of 01.03.2013 to the instrument cluster over chassis CAN 1, front SAM control unit and chassis CAN 2. The instrument cluster evaluates this information for issuing a country-specific seat belt reminder warning.
The seat belt reminder message for the front passenger is only issued, if the front passenger seat is recognized as occupied.
The Supplemental Restraint System control unit sends information on seat occupancy recognition up to 28.02.2013 via the chassis CAN to the instrument cluster or as of 01.03.2013 to the instrument cluster via chassis CAN 1, the front SAM control unit and chassis CAN 2.
A rear seat belt reminder warning is only issued when the total number of fitted seat belts in the rear changes during a journey or when the vehicle is at a standstill, without a rear door being opened.
If the total number of fitted seat belts in the rear changes, the instrument cluster actuates the seat belt warning lamp and the warning buzzer.
The rear SAM control unit with fuse and relay module (N10/2) sends information on the status of the rear seat belts to the instrument cluster via interior CAN.
The rear seat belt reminder warning is always issued as from v = 6 km/h. After t = 5 s or acknowledgment, the seat belt reminder warning is cleared.
An issued rear seat belt reminder warning does not exert any influence on triggered restraint equipment, it is only used to notify the driver.
The manner of how the seat belt reminder warning is issued differs in whether the seat belt reminder warning is prescribed by law or not and is incorporated into the assessment through the New Car Assessment Program (NCAP).
NCAP is an assessment program for safety in new vehicles.
Countries with legally prescribed seat belt reminder:
Extended NCAP:
USA, Canada, and up to 28.02.2013 Arab States of the Gulf, Korea and Japan
Countries without seat belt reminder warning prescribed by law:
Euro NCAP: Europe, China, Australia, and as of 01.03.2013 Arab States of the Gulf, Korea and Japan
In countries in which the seat belt reminder is prescribed by law (extended NCAP), the seat belt warning lamp (A1e9) is actuated for a period of t = 6 2 s. It is irrelevant here whether the driver seat belt is fitted or not. If the driver's seat belt is not being worn, the instrument cluster also issues an acoustic warning over the warning buzzer.
If the driver seat belt is then fitted, the acoustic warning is stopped.
There is no assessment here of whether the front passenger seat belt is fitted or not.
The status of both seat belts is evaluated only after a period of t = 6 s.
In countries in which the seat belt reminder warning is not prescribed by law, the seat belt warning lamp is only actuated during the indicator lamp test.
Immediately after detecting that the engine is running, the supplemental restraint system control unit evaluates the status of the driver and front passenger seat belts.
If a seat belt is defined to not be fitted, the instrument cluster actuates the seat belt warning lamp.
If the vehicle starts to move, additional acoustic warnings are issued when a speed of v 25 km/h is reached.
Three or four acoustic warnings are issued in accordance with the seat belt reminder warning. While these acoustic warnings are being issued, the seat belt warning lamp flashes on and off at a frequency of f = 2 Hz. After all the acoustic warning phases have expired the seat belt warning lamp is permanently actuated.
Acoustic warning phase 1:
If the vehicle drives off, acoustic warning phase 1 starts to run in the background. When a speed of v 25 km/h is reached, a quiet warning tone is issued at an interval of t = 4 s. Acoustic warning phase 1 lasts for a max of t = 20 s. Acoustic warning phase 2 then begins.
Acoustic warning phase 2:
After expiry of acoustic warning phase 1 and from a speed of v 25 km/h a quiet acoustic warning is issued for a maximum of t = 20 s at an interval of t = 2 s. Acoustic warning phase 3 then begins.
Acoustic warning phase 3:
After expiry of acoustic warning phase 2 and from a speed of v 25 km/h a quiet acoustic warning is issued for a maximum of t = 20 s at an interval of t = 1 s. Then acoustic warning phase 4 begins.
Acoustic warning phase 4 (Euro NCAP only):
After expiry of acoustic warning phase 3 and from a speed of v 25 km/h a loud acoustic warning is issued for a maximum of t = 93 s at an interval of t = 0.5 s.
Cancellation of seat belt reminder warning:
The last acoustic warning phase is fully completed.
The seat belt was fitted during the active seat belt reminder warning.
When the vehicle is stationary the vehicle door on the actuating side is opened.
Seat belt reminder warning reactivation:
Seat belt release has been detected again.
If the vehicle is at a standstill and the driver or front passenger door is opened and then closed again.
A new ignition cycle is detected from the time the "Engine running" or "Drive train operational" signal is set.