Instrument cluster, component description

P54.30-9720-76

Shown without code (494) USA version

A1 Instrument cluster

A1e1 Left turn signal indicator lamp

A1e2 Right turn signal indicator lamp

A1e3 High beam indicator lamp

A1e4 Fuel reserve indicator lamp

A1e7 Brake fluid and parking brake warning lamp

A1e9 Seat belt warning lamp

A1e15 Airbag indicator and warning lamp

A1e17 ABS indicator lamp

A1e29 Roll bar (RB [ÜRB]) indicator lamp

A1e30 ESP OFF indicator lamp

A1e41 ESP and ABS warning lamp

A1e54 Coolant temperature warning lamp

A1e58 Engine diagnosis indicator lamp

A1e59 DTR warning and indicator lamp
(with code (219) Distronic (DTR))

A1e66 Tire pressure monitor warning lamp (with code (470) Tire pressure monitor (standard) or with code (475) Tire pressure monitor (premium))

A1h1 Warning buzzer

A1p1 Coolant temperature gauge

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A1p2 Fuel level and reserve indicator

A1p5 Tachograph

A1p8 Electronic speedometer

A1p13 Left multifunction display

A1p15 Right multifunction display

A1r1 Instrument illumination brightness control and reset button

P Brightness sensor

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Location

The instrument cluster is located in the dashboard on the driver-side.

Task

The instrument cluster displays operating conditions and convenience displays as well as issuing visual and acoustic indicator and warning messages.

The instrument cluster has the following tasks:

 Reading in input factors

 Evaluation of input factors

 Component actuation

Reading in input factors

The instrument cluster reads in the input factors via the following connections:

 Interior CAN

 Engine compartment CAN

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Interior CAN

Input factors are read in from the following control units:

- COMAND operating, display and controller unit (A40/3)

- Rear SAM control unit (N10/8)

- Driver-side SAM control unit (N10/10)

- Right SAM control unit (N10/11)

- Lower control panel control unit (N72)

- Drive Unit control unit (N145)

- Steering column tube module (N80)

- TPM [RDK] control unit (N88) (with code (470) Tire pressure monitor (standard) or with code (475) Tire pressure monitor (premium))

- Keyless-Go control unit (N69/5)
(with code (889) Keyless-Go)

- Left door control unit (N69/1)

- Right door control unit (N69/2)

- Restraint systems control unit (N2/7)

- RVC control unit (N52)

- Overhead control panel control unit (N70)

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- Left front seat adjustment control unit with memory (N32/1)

- Right front seat adjustment control unit with memory (N32/2)

- EZS control unit (N73)

- Central gateway control unit (N93)

Engine compartment CAN

Input factors are read in from the following control units:

- ME-SFI [ME] control unit (N3/10)

- ESP, SPS [PML] and BAS control unit (N47-5)

- Fully integrated transmission control (VGS) control unit (Y3/8n4)

- DTR controller unit (A89)
(with code (219) Distronic (DTR))

- ABC control unit (N51/2)

- Electronic selector lever module control unit (N15/5)

Evaluation of input factors

The input factors that are read in are evaluated by the integrated processor of the instrument cluster and the affected components are actuated.

Component actuation

The instrument cluster actuates components in the following ways:

 Local Interconnect Network (LIN)

 Directly

LIN

The following component is actuated via LIN:

- Electronic clock (A70)

Directly

All the internal actuators (e.g. indicator and warning lamps, stepper motors of displays, multifunction display) are controlled directly by the instrument cluster.