Operation CHARM: Car repair manuals for everyone.

Part 1 of 2



GF54.30-P-2001RIT Indicator/warning Messages, Function
- with CODE (P99) Special model "AMG Black Series"


General function requirements
^ Instrument cluster (A1) activated

Indicator/warning messages, general
The instrument cluster indicator and warning messages notify the driver about the current states of the systems installed in the vehicle.

The instrument cluster can issue indicator and warning messages in the following ways:
- Optical issue of indicator and warning messages
- Acoustic output of indicator and warning messages

Visual indicator/warning messages:
The visual indicator and warning messages are displayed using the following instrument cluster components:
- Left multifunction display (A1p13)
- Right multifunction display (A1p15)
- Various indicator/warning lamps

Audible indicator/warning messages:
The acoustic indicator and warning messages are issued using the following instrument cluster components:
- Internal speaker "chime" (activated at a frequency of f = 1 Hz)
- Warning buzzer (A1h1) (activated at a frequency of f = 2.5 Hz)
- Acoustic turn signal indicator (A1h2)

The messages shown on the multifunction display are split up according to their level of urgency into three categories: A symbol is displayed in the left multifunction display and the corresponding fault text is displayed in the right multifunction display.
- Category 1 (messages with highest priority):
Category 1 messages indicate security hazard conditions or situations, and they cannot be acknowledged by pressing the instrument illumination and reset button brightness control (A1r1). When they occur, a brief chime or a cyclical warning tone is heard. The message is displayed in the left multifunction display and any category 2 or 3 messages present are faded out.
- Category 2 (messages with medium priority):
Category 2 messages can be acknowledged. When they occur, a brief chime is heard.
- Category 3 (messages with low priority):
Category 3 messages can be acknowledged. When they occur a warning chime is not heard.

The messages can all be displayed in the Service menu.

The indicator/warning messages consist of the following subfunctions:
^ Function sequence for cruise-control control/warning messages
^ Function sequence for rear wing control/warning messages
^ Function sequence for indicator/warning messages for the Electronic Stability Program (ESP)
^ Function sequence for control/warning messages for supplemental restraint system
^ Function sequence, national seat belt reminder warning
^ Function sequence for warning messages for the exterior lights (ABL)
^ Function sequence for tire pressure monitor (with code (470) Tire pressure monitor (standard))
^ Function sequence for emergency call system control/warning messages (with code (359) TELE AID emergency call system)
^ Function sequence for memory adjustment control message (with code (494) USA version)
^ Function sequence for Keyless-Go control/warning messages
^ Function sequence for audio/communication/navigation control messages
^ Function sequence for transmission-control control/warning messages
^ Function sequence for engine-control control/warning messages
^ Function sequence for brake wear indicator warning message
^ Function sequence for brake fluid level warning message
^ Function sequence, lights on reminder warning
^ Parking brake warning function sequence
^ Function sequence for engine oil level warning message
^ Function sequence for coolant and coolant temperature warning message
^ Function sequence for windshield washer system fluid level warning message
^ Function sequence, turn signal confirmation
^ Function sequence for tank cap open warning message (with code (494) USA version)

Additional function requirements for cruise-control control/warning messages
^ Engine running (circuit 61 ON)
^ Vehicle speed v > 30 km/h

The circuit 61 status is sent by the ME-SFI [ME] control unit (N3/10) to the engine compartment CAN (CAN C). The vehicle speed is calculated by the instrument cluster using the wheel speeds sent by the ESP, SPS [PML] and BAS control unit (N47-5) to the engine compartment CAN.

Function sequence for cruise-control control/warning messages
The cruise control regulates the vehicle speed to a configurable value and is activated over the CC [TPM] push button (S40).

The cruise-control control/warning messages consist of the following subfunctions:
^ Function sequence for cruise control display
^ Function sequence for variable speed limiter display (without code (494) USA version)
^ Function sequence for permanent limiter display

Function sequence for cruise control display
When the cruise control is switched on, "CC [TPM]" is shown and the set speed in the left multifunction display. If the cruise control malfunctions, the ME-SFI [ME] control unit sends the corresponding data over the engine compartment CAN to the instrument cluster. The instrument cluster receives the data and then issues corresponding messages on the multifunction displays.

Function sequence for variable speed limiter display
The variable speed limiter governs the vehicle speed to a configurable value that lies between v = 30 km/h and the maximum speed.

If the variable speed limiter is switched on, the configured speed is shown for t = 5 s in the left multifunction display (e.g. "Variable speed limiter 160 km/h"). The left multifunction display then returns to the display set by the driver. If the variable speed limiter malfunctions, the ME-SFI [ME] control unit sends the corresponding data over the engine compartment CAN to the instrument cluster. The instrument cluster receives the data and then issues corresponding messages on the multifunction displays.

Function sequence for permanent limiter display
The vehicle's maximum speed can be permanently governed on the instrument cluster to a value between 160 km/h (e.g. for winter tire operation) and the maximum speed. This is shown on the left multifunction display just before the speed stored in the permanent limiter is reached. If the permanent limiter malfunctions, the ME-SFI [ME] control unit sends the corresponding data over the engine compartment CAN to the instrument cluster.

The instrument cluster receives the data and then issues corresponding messages on the multifunction displays.

Additional function requirements for rear wing control/warning messages
^ Circ. 15 ON

The status of circuit 15 is sent by the EIS [EZS] control unit (N73) to the interior CAN (CAN B).

Function sequence for rear wing control/warning messages
The position of the rear wing is permanently monitored.
To this end, the AMG DRIVE UNIT control unit (N145) evaluates the signals of the following components:
- Left upper position sensor (B87/1)
- Right upper position sensor (B87/2)
- Left lower position sensor (B87/3)
- Right lower position sensor (B87/4)

If implausible positions for the rear wing are registered, the AMG DRIVE UNIT control unit sends corresponding information over the interior CAN to the instrument cluster. The instrument cluster receives the information, issues corresponding messages on the multifunction displays and also actuates the warning buzzer.

The following messages can be issued on the right multifunction displays:
- When the rear wing is retracted: "Caution. Retracting rear wing." in the right multifunction display. A pictogram of the spoiler is also shown on the left multifunction display with the arrow facing downwards.
- For a defective rear wing or defective rear wing control: "Rear wing control defective. Service required." in the right multifunction display.

Additional function requirements for ESP indicator/warning messages
^ Circuit 15 On (provided by EIS [EZS] control unit)

Function sequence for ESP indicator/warning messages
If the ESP has been switched to passive, the ESP control unit sends corresponding information over the engine compartment CAN to the instrument cluster. The instrument cluster receives the data and actuates the ESP and ABS warning lamp (A1e41) permanently. The left multifunction display also shows the "ESP" menu display and the right multifunction display shows the active ESP mode:
- "ESP", "ESP-ON"
- "ESP", "ESP-OFF"
- "ESP", "ESP-SPORT"

The corresponding ESP mode is requested by pressing the ESP OFF switch (N72s14).

The status of the ESP OFF switch is read in directly by the lower control panel control unit (N72) and sent to the instrument cluster on the interior CAN.
The central gateway control unit (N93) forwards the status of the ESP OFF switch over the engine compartment CAN to the ESP control unit. The ESP control unit activates the requested ESP mode and forwards the status of the active ESP mode over the engine compartment CAN to the instrument cluster.
When the ESP is switched off, the ESP OFF indicator lamp (A1e30) is also actuated.

If the ESP control unit detects any faults or malfunctions in the ESP system, it sends the corresponding information in the same manner. The instrument cluster receives the data and actuates the ABS indicator lamp (A1e17) and shows corresponding messages on the multifunction displays. ESP control interventions are indicated by the flashing ESP and ABS warning lamp.

Additional function requirements for supplemental restraint system control/warning messages
^ Circuit 15 On (provided by EIS [EZS] control unit)

Function sequence for control/warning messages for supplemental restraint system
If there is a fault in the supplemental restraint system, the supplemental restraint system control unit (N2/7) sends corresponding data over the interior CAN to the instrument cluster. The instrument cluster receives the data and actuates the airbag indicator and warning lamp (A1e15) and issues corresponding messages on the multifunction displays.
If seat belts are not fitted, the instrument cluster activates the seat belt warning lamp (A1e9), depending on the national version it then flashes or stays on constantly. As of a speed of v > 0 km/h, a warning tone also sounds

Additional function requirements, national seat belt reminder warning
^ Engine running (circuit 61 ON)
^ Driver or front passenger seat belts not inserted