Control/Warning Messages, Function - GF54.30-P-2001FH
Model 238
Up To Model Year 2021
Function requirements, general
- Terminal 15R On:
The electronic ignition lock control unit (N73) transmits the status of circuit 15 via the user interface CAN (CAN HMI) to the instrument cluster (A1).
Control/warning messages, general
The instrument cluster notifies the driver of the function or the status of the systems installed in the vehicle in the form of control and warning messages.
These messages can be output visually in the instrument cluster and acoustically through actuation of the instrument cluster speaker (H4/61) in the driver footwell.
Text messages or pictograms can be shown in the instrument cluster.
Symbols for control messages are displayed in the colors green, yellow, red or blue.
Symbols for warning messages are displayed in the color red.
Shown on model 238 except code 464 (Digital instrument cluster full display)
Model 238
up to model year 2021
with code 464 (Instrument cluster 12.3" diagonal)
The symbols available on the analog display as indicator and warning lamps are shown accordingly on the digital full display.
Function sequence for control/warning messages
The messages output in the instrument cluster are split up into four categories according to their level of urgency:
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 acoustic warning is emitted over the instrument cluster speaker.
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 acoustic warning is emitted over the instrument cluster speaker.
Category 3 and 4 (messages with low priority):
These messages are shown in the menu and they are only for providing information to 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 overlaid by the new message after the minimum display time has elapsed.
Operating feedback that requires little text is shown for t = 5 s as a one-line text field and then hidden again.
The instrument cluster is connected to the vehicle electronics system via user interface CAN.
The electronic ignition lock control unit sends requests to output control and warning messages from control units that are connected to one of the following CANs via user interface CAN to the instrument cluster:
- Interior CAN (CAN B)
- Diagnostic CAN (CAN D)
- Periphery CAN (CAN PER)
- Chassis FlexRay (Flex E)
Requests to issue control and warning messages from control units connected to one of the following CANs are sent by the powertrain control unit (N127) over the chassis FlexRay, electronic ignition lock control unit and the user interface CAN to the instrument cluster:
- Engine CAN (CAN C)
- Drive train CAN (CAN C1)
Requests to issue control and warning messages from control units connected to the drive train sensor CAN (CAN I), are sent by the CDI control unit (N3/9) or the ME-SFI [ME] control unit (N3/10) over the engine CAN, powertrain control unit, chassis FlexRay, electronic ignition lock control unit and the user interface CAN to the instrument cluster.
The systems and functions listed in the following table can request the output of control and warning messages through the corresponding control unit.
| System/Function | Control unit | Connection | Output | ||
|---|---|---|---|---|---|
| Indicator lamp/control message | Text message | Acoustic | |||
| Exhaust aftertreatment | AdBlue® control unit (N118/5) (engine 642 with code U77 (BlueTEC (SCR) diesel exhaust gas cleaning), engine 654 with code U79 (BlueTEC (SCR) diesel exhaust gas cleaning, generation 3)) | CAN I/CAN C/Flex E/CAN HMI | x | - | |
| DISTRONIC distance pilot (with code 239 (DISTRONIC distance pilot) or code 23P (Driving assistance package)) | DISTRONIC distance pilot controller unit (A108/1) Intelligent Drive control unit (N62/4) | Flex E/CAN HMI | DISTRONIC warning message | - | x |
| ADAPTIVE BRAKE | Electronic Stability Program control unit (N30/4) | Flex E/CAN HMI | Anti-lock braking system control message, Electronic Stability Program warning message, brake system warning message, brake force distribution warning message | x | - |
| Adaptive Highbeam Assist (with code P35 (Light package)) | Front SAM control unit (N10/6) | CAN B/CAN HMI | High beam control message | x | - |
| AIR BODY CONTROL (with code 489 (AIR BODY CONTROL)) | AIR BODY CONTROL, control unit (N51/3) AIR BODY CONTROL Plus control unit (N51/8) | Flex E/CAN HMI | - | x | - |
| Active Brake Assist (with code 258 (Active Brake Assist)) | Active Brake Assist controller unit (A108) | CAN PER/CAN HMI | - | x | x |
| Active Brake Assist with intersection function (with code 23P (Driving assistance package)) | Intelligent Drive control unit (N62/4) | Flex E/CAN HMI | - | x | - |
| Active Blind Spot Assist (with CODE 23P (Driving assistance package)) | Intelligent Drive control unit (N62/4) | Flex E/CAN HMI | - | x | x |
| Active Lane Keeping Assist (with CODE 23P (Driving assistance package)) | Stereo multifunction camera (A40/13) | Flex E/CAN HMI | - | x | - |
| Active Lane Keeping Assist (with code 22P (Lane Keeping Package)) | Mono multifunction camera (A40/11) | CAN PER/CAN HMI | - | x | x |
| Trailer recognition (with CODE 550 (Trailer hitch)) | Trailer recognition control unit (N28/1) | CAN B/CAN HMI | Trailer control message | x | - |
| Attention assistance system | Electronic Stability Program control unit (N30/4) | Flex E/CAN HMI | - | x | x |
| Audio/Navigation/Communication | Head unit (A26/17) | HMI CAN | - | x | - |
| Automatic transmission control (transmission 725) | Fully integrated transmission control unit (Y3/8n4) | CAN C1/Flex E/CAN HMI | - | x | - |
| Exterior lights (ABL) | Front SAM control unit (N10/6) or rear SAM control unit (N10/8) | CAN B/CAN HMI | Low beam control message, high beams control message, rear fog light control message (except code 460 (Canada version) and except code 494 (USA version)), standing light control message | x | x |
| Left headlamp control unit (E1n9) or right headlamp control unit (E2n9) | CAN PER/CAN HMI | x | - | ||
| Turn signal confirmation | Front SAM control unit (N10/6) | CAN B/CAN HMI | Left turn signal light control message, right turn signal light control message | - | x |
| Brake fluid level | Front SAM control unit (N10/6) | CAN B/CAN HMI | Brake system warning message | x | - |
| Brakepad wear display | Front SAM control unit (N10/6) | CAN B/CAN HMI | - | x | - |
| Energy management | Front SAM control unit (N10/6) | CAN B/CAN HMI | - | x | - |
| Electrical power steering | Electrical power steering control unit (N68) | Flex E/CAN HMI | Brake system warning message | x | - |
| Electronic Stability Program (ESP®) | Electronic Stability Program control unit (N30/4) | Flex E/CAN HMI | ESP®/ASR OFF warning message (ESP® ON/OFF status), Electronic Stability Program warning message (ESP® system active) | x | - |
| Suspension (model 238.3 as of 01.12.2017 or model 238.4, with code 459 (Steel suspension with adjustable damping) or code 489 (AIR BODY CONTROL)) | AIR BODY CONTROL, control unit (N51/3) Adaptive damping system control unit (N51/5) AIR BODY CONTROL Plus control unit (N51/8) | Flex E/CAN HMI | Suspension malfunction control message | - | - |
| Windshield washer system fluid level | Front SAM control unit (N10/6) | CAN B/CAN HMI | - | x | - |
| Speed warning (Gulf States national version) | Instrument cluster (A1) | Internal | - | x | x |
| Seat belt reminder warning | Supplemental Restraint System control unit (N2/10) | HMI CAN | Seat belt warning lamp | - | x |
| Rear SAM control unit (N10/8) | CAN B/CAN HMI | - | x | x | |
| KEYLESS-GO | KEYLESS-GO control unit (N69/5) | CAN B/CAN HMI | - | x | - |
| Climate control | Climate control, control unit (N22/1) | CAN B/CAN HMI | - | x | x |
| Fuel system | Fuel system control unit (N118) | CAN C1/Flex E/CAN HMI | - | x | - |
| Coolant level | Front SAM control unit (N10/6) | CAN B/CAN HMI | - | x | - |
| Coolant temperature | CDI control unit (N3/9) (diesel engine) or ME- SFI [ME] control unit (N3/10) (gasoline engine) | CAN C/Flex E/CAN HMI | Coolant temperature message | x | - |
| Lights on warning | Front SAM control unit (N10/6) | CAN B/CAN HMI | - | x | x |
| Memory adjustment (with code 275 (Memory package)) | Driver's seat control unit (N32/1), front passenger seat control unit (N32/2) | CAN B/CAN HMI | - | - | x |
| Engine management | CDI control unit (N3/9) (diesel engine) or ME- SFI [ME] control unit (N3/10) (gasoline engine) | CAN C/Flex E/CAN HMI | Engine diagnosis control message | x | - |
| Engine oil level warning | CDI control unit (N3/9) (diesel engine) or ME- SFI [ME] control unit (N3/10) (gasoline engine) | CAN C/Flex E/CAN HMI | - | x | - |
| Emergency call system (with code 360 (HERMES UMTS) or code 362 (HERMES LTE)) | HERMES control unit (N112/9) | CAN D/CAN HMI | - | x | - |
| Parking system (with code P44 (Parking Package) or code 235 (Parking Pilot with PARKTRONIC)) | Parking system control unit (N62) | Flex E/CAN HMI | - | x | x |
| PRE-SAFE® | Left front reversible emergency tensioning retractor (A76) or right front reversible emergency tensioning retractor (A76/1) | HMI CAN | Supplemental Restraint System control message | x | - |
| Tire pressure monitor (with code 475 (Tire pressure monitor)) | Tire pressure monitoring system control unit (N88) | HMI CAN | Tire pressure monitoring system warning message | x | - |
| Tire pressure loss warning (with code 477 (Tire pressure loss warning)) | Electronic Stability Program control unit (N30/4) | Flex E/CAN HMI | - | x | - |
| Manual transmission (transmission 716) | Powertrain control unit (N127) | Flex E/CAN HMI | - | x | - |
| Stationary heater (with CODE 228 (Stationary heater)) | Stationary heater control unit (A6n1) | LIN B8-2/CAN B/CAN HMI | - | x | - |
| Supplemental restraint system | Supplemental Restraint System control unit (N2/10) | HMI CAN | Supplemental Restraint System control message | x | - |
| Fuel cap warning (with code 494 (USA version)) | CDI control unit (N3/9) (diesel engine) or ME- SFI [ME] control unit (N3/10) (gasoline engine) | CAN C/Flex E/CAN HMI | Fuel reserve warning message | x | - |
| Cruise control (except CODE 23P (Driving assistance package)) | Electronic Stability Program control unit (N30/4) | Flex E/CAN HMI | Speedometer segment ring | x | x |
| Cruise control (with CODE 23P (Driving assistance package)) | Intelligent Drive control unit (N62/4) | Flex E/CAN HMI | Speedometer segment ring | x | x |
| Blind Spot Assist (with CODE 22P (Lane package)) | Integrated outer right rear bumper radar sensor (B92/6) | CAN PER/CAN HMI | - | x | x |
| Doors OPEN warning | Front SAM control unit (N10/6), rear SAM control unit (N10/8), left front door control unit (N69/1), right front door control unit (N69/2) | CAN B/CAN HMI | - | x | x |
| Soft top control (model 238.4) | Rear control unit (N22/6) | CAN B | - | x | x |
| Traffic Sign Assist (with CODE 513 (Traffic Sign Assist)) | Mono multifunction camera (A40/11), Stereo multifunction camera (A40/13) | CAN PER/CAN HMI Flex E/CAN HMI | - | x | - |
| Preglow indicator (diesel engine) | CDI control unit (N3/9) | CAN C/Flex E/CAN HMI | Preglow control message | - | - |
Special case of country-dependent seat belt reminder warning:
If a seat belt is detected as not being worn directly before starting a journey or whilst travelling, then, depending on the country, the instrument cluster will issue an optical warning and a warning tone (seat belt warning).
The Supplemental Restraint System control unit (N2/10) sends information on the status of the driver and front passenger seat belts to the instrument cluster via user interface CAN.
The rear SAM control unit (N10/8) transmits information on the status of the rear seat belts via interior CAN, electronic ignition lock control unit and user interface CAN to the instrument cluster.
The instrument cluster evaluates this information for issuing a seat belt reminder warning.
The seat belt reminder message for the front passenger is only issued if the front passenger seat is occupied. The Supplemental Restraint System control unit sends information on the assignment of front passenger seat to the instrument cluster via user interface CAN. The rear seat belt reminder warning is always issued as from v = 6 km/h. After t = 5 s or acknowledgment, the rear seat belt reminder warning is cleared. The output of the rear seat belt warning does not have any effect on the deployment of the restraint equipment; it only serves as information for the driver.
The way in which the seat belt reminder warning is output depends on whether the seat belt reminder warning is legally required or not and contributes to the assessment by the New Car Assessment Program (NCAP).
NCAP is a program for assessing the safety of new vehicles.
- Countries with legally prescribed seat belt reminder:
Extended NCAP: USA and Canada
- Countries without seat belt reminder warning prescribed by law:
European New Car Assessment Program (Euro NCAP): Europe, China, Australia, Japan, Arab States of the Gulf and Korea
In countries in which the seat belt reminder is prescribed by law (extended NCAP), the seat belt warning message 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 fastened, the instrument cluster also outputs an acoustic warning over the instrument cluster speaker.
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 t = 6 s have elapsed. In countries in which the seat belt warning is not required by law, the seat belt warning message is only actuated during the control display test.
As soon as engine start is detected ("Engine running" signal or "Drive train ready" set), information on the status of seat belts for driver and front passenger is evaluated. If a seat belt is recognized as not being fitted, the seat belt warning message lights up. If the vehicle then starts to move, several acoustic warning phases are run through once a speed of v ≥ 25 km/h is reached.
Depending on the type of seat belt warning issued, three or four acoustic warning phases are issued in succession. While they 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. t = 20 s. Acoustic warning phase 2 is then started.
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 is then started.
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. Acoustic warning phase 4 is then started.
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 ("Engine running" or "Drive train operational" signal set).
| Electrical function schematic of instrument cluster, control/warning message | PE54.30-P-2054-97DCA | ||
| Overview of system components, instrument cluster (IC) component description | GF54.30-P-9996FH |