L322 Range Rover System Description and Operation
ENTERTAINMENT AND INFORMATION SYSTEMS
DESCRIPTION AND OPERATION 86-8-21
Six rocker buttons are located below the MID. Each rocker button has a pressure point on the left and the right. There
are effectively 12 switching levels for this button unit. Arranged to the right next to the display are the buttons for the
selection of AUDIO, DSP, TELEPHONE, CLOCK and BC (on-board computer). The AUDIO button has one pressure
point each on the left and right. In the case of versions with DSP, the left pressure point is assigned to AUDIO and
the right to DSP. The buttons for TELEPHONE with the handset symbol and BC with the CLOCK are laid out as rocker
buttons. To the left next to the display is a rocker button for the search and scan functions. The button for the manual
search function is inserted in the centre of this rocker button. A rotary increment sensor is used to control AUDIO and
the hands-free speaking feature of the telephone volume, as well as the ON / OFF switch for the AUDIO system. This
is carried out by means of an increment sensor with an integrated push switch. The rotary controller has 36
incremental steps of 10
°
each.
The MID lighting is controlled by a photo-transistor sensor. The brightness of the lighting can also be influenced
manually by the instrument lighting dimmer. When the vehicle lighting is switched off, the display brightness is
governed exclusively via the sensor, this gives a daytime minimum brightness of 60 % of the control range is defined.
When the instrument dimmer is switched on, the controlling range from the daytime minimum brightness onward is
expanded by the dimension of the dimmer position. The dimmer position is taken from the "dimming" message. With
"light off" the LED function indications are activated at the maximum level and with "light on" with the value of the day/
night threshold, irrespective of the photo-transistor.
Control signals for the MID are sent along the I-bus.
MID Harness Connector C0241 Pin Details
Diagnostics
The MID is capable of being subjected to diagnostics. The principle applies of finding the smallest replaceable unit
via the diagnostics computer (TestBook/T4). The instrument pack serves as a gateway between the diagnostics bus
and the I-bus. The messages from TestBook/T4 are converted by the instrument pack into the respective I-bus format.
The MID detects the diagnostics mode by means of the diagnostics computer address. Normal operation is
maintained during the diagnostics mode. MID diagnostics are subdivided into two categories:
l
Device identification
l
Self-diagnostics with error storage.
Control unit identification is stored in the EEPROM of the MID and can be called up by means of the diagnostics tester.
The data is programmed at the point of manufacturer.
Errors detected by the MID are stored in the EEPROM. The errors are stored in the order of their occurrence. Each
error is assigned an error code. In order to avoid the entry of "false errors", the error memory is not written to in the
first 500 ms after the power-on reset. The frequency counter is incremented with each detected error. The error type
is set to "momentarily present". After the error is corrected, the error type is set to "sporadic (not momentarily
present)". The error frequency counter stores a maximum of 31 errors. Once this limit is reached, the error type
remains constantly on "momentarily present". Any fault codes can only be removed by the manufacturer.
Pin No.
Description
Input/Output
1
Ground
–
2
Permanent power supply from battery
Input
3
Interior illumination
Input
4
I bus
Input/Output
5 to 7
Not used
–
8
Auxiliary power supply
Input
9 to 12
Not used
–