Part 2 of 2
Additional function requirement for AIRmatic control/warning messages (with model 164.1, 251 with code (489) AIRmatic (air suspension with level adjustment and adaptive damping system (ADS)), model 164.8)^ Circuit 61 ON
The circuit 61 status is sent by the CDI control unit (N3/9) (on diesel engine) or by the motor electronics control unit (N3/10) (on gasoline engine) to the engine compartment CAN.
Function sequence for control/warning messages for AIRmatic
If the AIRmatic control unit (N51) (model 164) or AIRmatic with ADS control unit (N51) (model 251) detects an error in the AIRmatic system, it sends a corresponding signal over the engine compartment CAN to the instrument cluster. The instrument cluster shows the corresponding message on the multifunction display. There are various system messages or warning messages with different fault priorities. If several faults exist at the same time, several fault messages will be output accordingly.
Additional function requirements, door open reminder warning
^ Vehicle speed v > 3 km/h (calculated by instrument cluster)
Function sequence, door open reminder warning
If, at a vehicle speed of v > 3 km/h, an open door, rear-end door or engine hood is detected, the instrument cluster actuates the warning buzzer and also displays a corresponding message on the multifunction display. The rear SAM control unit sends the corresponding status for the doors, rear-end door and the engine hood over the interior CAN to the instrument cluster.
Additional function requirements for exterior lighting (ABL) warning messages
^ Circuit 15 ON (sent by EIS [EZS] control unit to interior CAN)
Exterior lighting (ABL) function sequence
The function of the exterior lights (ABL) components is permanently monitored. If a fault is detected on a component, the monitoring control unit sends a corresponding signal over the interior CAN to the instrument cluster. In response, the instrument cluster shows a corresponding warning message on the multifunction display.
The following control units monitor the function of the exterior lights (ABL) components:
- Front SAM control unit (N10) (exterior lights on front of vehicle)
- Rear SAM control unit (exterior lights on vehicle rear and trailer lighting (with code (550) Trailer hitch))
- Left front door control unit (N69/1) (left outside mirror turn signal lamp (E6/5))
- Right front door control unit (N69/2) (right outside mirror turn signal lamp (E6/6))
Additional function requirements for parking brake on reminder warning
^ Vehicle speed v > 5 km/h (calculated by instrument cluster)
Parking brake warning function sequence
If, at a vehicle speed of v > 5 km/h, the parking brake inspection switch (S12) is pressed, the instrument cluster issues an acoustic warning and a message is shown on the multifunction display.
The brake fluid and parking brake warning lamp (A1e7) is also actuated.
The status of the parking brake inspection switch is read by the front SAM control unit and transmitted via the interior CAN to the instrument cluster.
Additional function requirements for speed warning (with code (623) Gulf States version)
^ Vehicle speed v > 120 km/h (calculated by instrument cluster)
Vehicle speed warning function sequence
If a vehicle speed of v = 120 km/h is exceeded, the instrument cluster issues an acoustic warning.
Additional function requirements, national seat belt reminder warning
^ Circuit 61 ON (sent by CDI control unit or from the ME-SFI [ME] control unit to the engine compartment CAN)
^ Circuit 15 On (with code (498) Japan version) (sent by EIS control unit to interior CAN)
National seat belt reminder warning function sequence
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 instrument cluster evaluates the following information for issuing a country-specific seat belt reminder warning:
- As sent by the restraint system control unit to the engine compartment CAN:
- Driver seat belt buckle and seat belt reminder warning switch status (S68/1)
- Front passenger seat belt buckle and seat belt reminder warning switch status (S68/2)
- Front passenger seat occupation status (without code (494) USA version)
- Left rear seat belt buckle switch (S68/11) (model 164.1)
- Right rear seat belt buckle switch (S68/12) (model 164.1)
- Center rear seat belt buckle switch (S68/14) (model 164.1)
- Sent by Weight Sensing System (WSS) control unit (N2/13) (with code (494) USA version) to interior CAN:
- Front passenger seat occupancy status
- Sent from left front door control unit to interior CAN:
- Left front door status
- Sent from right front door control unit to interior CAN:
- Right front door status
- As sent by the ESP control unit to the engine compartment CAN:
- Wheel speeds for calculating the speed
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).
The New Car Assessment Program (NCAP) is a program for assessing the safety of new vehicles. Countries with seat belt reminder warning prescribed by law (extended NCAP):
- Japan, USA, Canada, Arab States of the Gulf, Korea Countries with no seat belt reminder warning provided by law (EURO-NCAP):
- Countries of Europe, China, Australia
In countries in which the seat belt reminder warning is prescribed by law, the seat belt warning lamp (A1e9) is actuated for a time interval 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 fitted, the instrument cluster also issues an acoustic warning over the internal warning buzzer. To this end, the instrument cluster evaluates the status of the driver seat belt buckle and seat belt reminder warning switch.
If the driver seat belt is fitted during this time interval, the acoustic warning is canceled.
An assessment of whether the front passenger seat belt is fitted or not given during this time interval.
Only after the time interval of t = 6 s has expired, does the assessment of both seat belts occur.
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 the engine running characteristics (circuit 61) both the status of the driver seat belt buckle and seat belt reminder warning switch as well as the status of the front passenger seat belt buckle and seat belt reminder warning switch are assessed.
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, when it reaches a speed of v ≥25 km/h, further successive acoustic warnings are issued. Three or four acoustic warnings are issued in accordance with the seat belt reminder warning. While they are being issued the seat belt warning lamp is actuated at a frequency of f = 1 Hz.
- Acoustic warning phase 1:
As the vehicle starts to drive off, acoustic warning phase 1 also starts in the background. When a speed of v ≥ 25 km/h is reached a quiet acoustic warning is sounded at an interval of t = 4 s. The acoustic warning phase 1 last for a maximum t = 20 s. This is then followed by a transition to acoustic warning phase 2.
- Acoustic warning phase 2:
After expiry of acoustic warning phase 1 and at a speed of v ≥ 25 km/h a quiet acoustic warning is sounded for maximum t = 20 s at an interval of t = 2 s. This is then followed by a transition to acoustic warning phase 3.
- Acoustic warning phase 3:
After expiry of acoustic warning phase 2 and at a speed of v ≥ 25 km/h a quiet acoustic warning is sounded for maximum t = 20 s at an interval of t = 1 s. This is then followed by a transition to acoustic warning phase 4.
- Acoustic warning phase 4 (EUO NCAP only):
After expiry of acoustic warning phase 3 and at a speed of v ≥ 25 km/h a quiet acoustic warning is sounded for maximum t = 93 s at an interval of t = 0.5 s.
When an acoustic warning is emitted the seat belt warning lamp is actuated and it flashes on and off. Once all the acoustic warning phases have been passed through it is actuated permanently.
Actuation of warning lamp:
- Extended NCAP:
- The warning lamp is actuated for a period of t = 6 s until the vehicle reaches a speed of v > 25 km/h. As from this speed the warning lamp starts to blink, until the driver seat belt buckle and seat belt reminder warning switch or the front passenger seat belt buckle and seat belt reminder warning switch (with detected seat occupation) are recognized as being fitted.
- Euro NCAP:
- As from a speed of v > 25 km/h the warning lamp starts to blink, until the driver seat belt buckle and seat belt reminder warning switch or the front passenger seat belt buckle and seat belt reminder warning switch are recognized as being fitted.
The seat belt reminder warning is deactivated under the following circumstances:
- Last acoustic warning phase run through completely
- Driver seat belt or front passenger seat belt now fitted
- Door on passenger side opened, at which the seat belt reminder warning was triggered (driver seat belt reminder
warning = driver door, front passenger seat belt reminder
warning = front passenger door) at vehicle standstill
The seat belt reminder warning is activated again under the following circumstances:
- When the seat belt is removed again
- Vehicle at standstill and driver or front passenger door is opened and then closed again
- When an ignition sequence is detected again as of circuit 61 On or circuit 15 On (with code (498) Japan version)
The seat belt reminder warning for the rear passengers is realized by monitoring the total number of belt tabs inserted into the seat belt buckles in the rear.
Additional function requirements for coolant level and coolant temperature warning
^ Circuit 15 ON (sent by EIS [EZS] control unit to interior CAN)
Function sequence for coolant level and coolant temperature warning
The coolant level in the expansion reservoir is monitored by the coolant level indicator switch (S41).
The status of the coolant level indicator switch is read in by the front SAM control unit. If the coolant level is too low the front SAM control unit sends a corresponding signal over the interior CAN to the instrument cluster. In response the instrument cluster shows a warning message on the multifunction display.
The coolant temperature is recorded by the coolant temperature sensor (B11/4). The CDI control unit or the ME-SFI [ME] control unit reads in the signals of the coolant temperature sensor and sends them to the instrument cluster via the engine compartment CAN.
If the coolant temperature is too high the CDI control unit CDI or the ME-SFI [ME] control unit sends a corresponding signal over the engine compartment-CAN to the instrument cluster. In response, the instrument cluster shows a warning message on the multifunction display.
Additional function requirements for engine oil level warning
^ Circuit 15 ON (sent by EIS [EZS] control unit to interior CAN)
Engine oil level warning function sequence
In order to monitor the engine oil level, engine oil temperature and the engine oil pressure, the switch oil level check (S43) (without engine 629.9) or the oil sensor (oil level, temperature and quality) (B40) (with engine 629.9) is installed in the engine oil pan. The signals of the oil level check switch or oil sensor are read in by the CDI control unit or from the ME-SFI [ME] control unit and evaluated.
If necessary, the CDI control unit or the ME-SFI [ME] control unit sends a corresponding signal via the engine compartment CAN to the instrument cluster. In response, the instrument cluster shows a corresponding warning message on the multifunction display.
Additional function requirements for preglow check (with diesel engine)
^ Circuit 15 ON (sent by EIS [EZS] control unit to interior CAN)
Function sequence, preglow indicator
Preglowing is controlled by the CDI control unit. For the period of time in which the preglowing is active, the CDI control unit sends a corresponding signal via the engine compartment CAN to the instrument cluster. The instrument cluster then actuates the preglow indicator lamp (A1e16).
The function of the preglow indicator lamp is monitored by the on-board diagnosis (OBD).
Additional function requirements for brake pad wear indicator warning messages
^ Circuit 15 ON (sent by EIS [EZS] control unit to interior CAN)
Function sequence for brake wear indicator warning messages
When the brake lining wear limit for the front and rear axles is reached, it is detected by the right front brake pad contact sensor (S10/2) and the right rear brake pad contact sensor (S10/4). The status of the brake pad contact sensor is read in by the front SAM control unit. If the wear limit is reached, the front SAM control unit sends a corresponding signal over the interior CAN to the instrument cluster. As a result of which the instrument cluster actuates the brake fluid and parking brake warning lamp and outputs a warning message via the multifunction display.
Additional function requirements for brake fluid level warning messages
^ Circuit 15 ON (sent by EIS [EZS] control unit to interior CAN)
Function sequence for brake fluid level indicator warning messages
if the fluid level in the brake fluid reservoir is too low it is detected by the brake fluid check switch (S11). The status of the brake fluid check switch is read in by the front SAM control unit. If the fluid level is too low the front SAM control unit sends a corresponding signal over the interior CAN to the instrument cluster. In response, the instrument cluster actuates the brake fluid and parking brake warning lamp or the brake indicator lamp (A1e64) (with code (494) USA version) and also shows a corresponding warning message on the multifunction display.
Additional function requirements for windshield washer system fluid level warning messages
^ Circuit 15 ON (sent by EIS [EZS] control unit to interior CAN)
Function sequence for windshield washer system fluid level warning messages
The fluid level in the washer fluid reservoir is monitored by the windshield washer system fluid level indicator switch (S42 The status of the windshield washer system fluid level indicator switch is read in by the front SAM control unit.
If the fluid level is too low the front SAM control unit sends a corresponding signal over the interior CAN to the instrument cluster. In response the instrument cluster shows a corresponding warning message on the multifunction display
Turn signal confirmation function sequence
Acoustic feedback about the active turn signal light actuation is realized by the acoustic turn signal indicator integrated into the instrument cluster.
The visual feedback takes place via the left turn signal indicator lamp (A1e1) and right turn signal indicator lamp (A1e2).
Additional function requirement for filler cap warning (with code (494) USA version)
^ Circuit 15 ON (sent by EIS [EZS] control unit to interior CAN)
Function sequence for tank cap warning
The rear SAM control unit monitors the status of the tank cap. If the tank cap is not closed, the rear SAM control unit sends a corresponding signal over the interior CAN to the instrument cluster, which then actuates the fuel reserve warning lamp (A1e4) and shows a warning message on the multifunction display.
Function sequence warning messages for AdBlue(R) (with code (U42) BlueTEC (SCR) diesel exhaust treatment)
If the AdBlue(R) control unit (N118/5) detects a fault, it sends a corresponding signal over the drive train sensor CAN (CAN I) to the CDI control unit.
The CDI control unit sends the signal over the engine compartment-CAN to the instrument cluster. In response the instrument cluster shows a warning message on the multifunction display.
