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Navigation - Control Module Function



Control Unit Function

Terminal Resistance On The CAN
To prevent reflection on the wiring, the ends of the wires are each provided with a terminal resistor, which are integrated into two control modules.

CAN Comfort
Communication between the Porsche System Tester II No. 9588 and the MOST control modules only takes place via the K lead to the instrument cluster. The data is transferred from the instrument cluster gateway to the MOST control modules via CAN comfort to the PCM2 gateway, via the electrical MOST in the PCM2 and via the optical MOST outside of the PCM2.

CD Changer (CDC)
The CDC is available as an optional feature and is linked to the PCM2 via the optical waveguide.

Coding
It is possible to extract the chassis number and to code the PCM2 on a country-specific basis under this 'Modify coding' menu.

Menu Item Function

- Chassis number It is possible to extract or enter the chassis number under this menu item after replacing the PCM2-GW.
- Connect and start the Porsche System Tester II No. 9588 and switch on the ignition.
- Select vehicle type 911 (996) and control module PCM2 and press the >> key.
- Select menu item Coding.
- Select the "Chassis number" menu item.
- Enter the chassis number and code with the F8 key.

- Country coding Using this menu item, you can code the country code:
- Connect and start the Porsche System Tester II No. 9588 and switch on the ignition.
- Select vehicle type 911 (996) and control module PCM2-GW and press the >> key.
- Select the 'Coding' menu item and press the >> key.
- Select the "Country coding" menu item and press the >> key.
- Select "RoW or USA" and code with the F8 key.

Data Transfer Fault
If faults are detected when the data is decoded, this is known as a data transfer fault. The faults can arise when the data is coded, when the data is transferred through an input level that is optically too low or when the data is decoded. A fault entry is not made.

Diagnosis Distribution Line
The diagnosis distribution line is an electrical lead, which, as a stub cable, connects the individual MOST control modules in the system with one another. The existing MOST control modules are electrically/optically checked at regular intervals during communication with the control modules via the MOST.

Function Of The Components







Gateway
The gateway is integrated in the PCM2. Together with the MMI, it is a fixed component of each PCM2. It provides a connection to CAN Comfort via its nodes. Diagnosis and useful data is exchanged with CAN via these nodes.

It creates links to the following systems:
- CAN Comfort
- Media Oriented Systems Transport (MOST), internal (electrical)
- Voice control system (VOCS) (optional/insertion)
- Navigation (optional/rack)
- Man Machine Interface (MMI)
- Single CD
- Media Oriented Systems Transport (MOST), external bus (optical)
- Amplifier optional (Harman or BOSE)
- CD changer
- Telephone/telematics

Identification
The diagnosis software number and the part numbers for the PCM2 can be read out under this menu item.
1. Connect and start the Porsche System Tester II No. 9588 and switch on the ignition.
2. Select vehicle type 911 (996) and control module PCM2 and press the >> key.
3. Select the "Identification" menu item and press the >> key.
4. The message "Diagnosis software number; PCM2. parts number" appears on the display.

Actual Values
It is possible to read out the unlock counter under the 'Actual values' menu item.

Menu Item Function

- Unlock counter Under this menu item, it is possible to check the electrical and optical MOST during troubleshooting.
- Connect and start the Porsche System Tester II No. 9588 and switch on the ignition.
- Select vehicle type 911 (996) and control module PCM2-GW and press the >> key.
- Select the Actual values menu item and press the >> key.
- Select the "Unlock counter" menu item using the > key and press the >> key.
- Read out values from the display field.

Lock/Unlock
A lock occurs when the signal sent from the MMI via the wake-up/diagnosis distribution line is understood and answered by the connected MOST control modules; in this way a 'lock (connection)' is brought about. This is maintained until the signal is not received for a longer time 'unlock'.

Man Machine Interface (MMI)
The MMI is part of the PCM2 (on the mainboard) It runs the gateway commands via the wake-up signal line and the diagnosis of the distribution line.

MOST Actual Installations List/MOST Required Installations List
All MOST control modules that are connected to the PCM2 are entered in the 'required installations list'. An actual installations list is written and saved when the PCM2 is started.

MOST - Optical/Electrical
MOST signals are transferred electrically within the PCM2 and optically outside of the PCM2. Internally, the PCM2 consists of at least 2 nodes (GW and MMI), which are installed in the device and can also be expanded to four nodes by adding the navigation and ARS nodes.

The data is transferred outside of the PCM2 via the optical waveguide, which creates a connection to the nodes in the external MOST control modules such as external amplifiers, CD changers and/or telephone/telematics (depending on the equipment). The gateway node represents the connection to CAN Comfort.

MOST Switch
The MOST switch is part of the PCM2. It keeps the electrical MOST closed if no other MOST control module is optically connected to the MOST. The MOST switch is opened when a light signal is received from the connected MOST control modules.

NOTE:
- When the PCM2 is replaced, the coding must be performed in accordance with the connected MOST control modules.
- When the 'Switch closed' parameter is set, the switch remains closed even in existing MOST control modules. Communication is then not possible.

Navigation
The navigation module is designed as a module box which can be pushed into the PCM2 (optional). After inserting, an electronic connector is automatically opened and the module is integrated into the MOST ring.

Voice Control System (VOCS)
The VOCS is designed as a module box which can be pushed into the PCM2 (optional). After inserting, an electronic connector is automatically opened and the module is integrated into the MOST ring.

Control Unit PCM2 (Head Unit)
The PCM2 control unit (head unit) includes the following components:

Internal:
PCM2 Gateway
PCM2 Man Machine Interface (MMI)
Internal amplifier (optional, depending on the equipment)
Tuner
Single CD
Navigation (optional/rack)
VOCS (voice control system) (optional/Insertion)
Wake-up and diagnosis distribution breakage line control
Controller Area Network (CAN) Comfort
MOST switch

External:
External amplifier (optional, Harman or BOSE)
Telephone/Telematics (optional)
CD changer (CDC), (optional)

The PCM2 consists of at least two but a maximum of four MOST nodes, (Gateway, MMI and Navigation and VOCS (optional)), which communicate with each other via the electronic MOST. Data outside the PCM2 is transferred via the optical MOST.

Single CD
The CD player is part of the PCM2. It is used to update the navigation system.

Input Signals
The following queries can be run using this menu item:
- Tuner parameter
- Registry startup status
- Internal ring startup status
- External ring startup status

NOTE: Deactivate the 'automatic traffic announcement' before performing the diagnosis on the PCM2. If this is not done, the diagnosis will abort.

Menu Item Function

- Tuner parameter Under this menu item, it is possible to check the electrical and optical MOST during troubleshooting.
- Connect and start the Porsche System Tester II No. 9588 and switch on the ignition.
- Select vehicle type 911 (996) and control module PCM2-GW and press the >> key.
- Select the Input signals menu item and press the >> key.
- Select the "Parameter tuner" menu item using the > key and press the >>key.
- Read out values from the display field.

- Registry startup status Using this menu item, you can read out the installation list.
- Connect and start the Porsche System Tester II No. 9588 and switch on the ignition.
- Select vehicle type 911 (996) and control module PCM2-GW and press the >> key.
- Select Input signals and press the >> key.
- Select the "Registry startup status" menu item using the > key and press the >> key.
- Read out values from the display field.

- Internal ring startup
status Under this menu item, it is possible to check the electrical MOST during troubleshooting.
- Connect and start the Porsche System Tester II No. 9588 and switch on the ignition.
- Select vehicle type 911 (996) and control module PCM2-GW and press the >> key.
- Select the Input signals menu item and press the >> key.
- Select the "Internal ring startup status" menu item using the > key and press the >>key.
- Read out values from the display field.

- External ring
startup status Under this menu item, it is possible to check the optical MOST during troubleshooting.
- Connect and start the Porsche System Tester II No. 9588 and switch on the ignition.
- Select vehicle type 911 (996) and control module PCM2-GW and press the >> key.
- Select the Input signals menu item and press the >> key.
- Select the "External ring startup status" menu item using the > key and press the >> key.
- Read out values from the display field.

Drive Links
Drive links of the PCM2 can be activated with this menu item. This allows the function of the drive links to be assessed very quickly.

The following drive links can be controlled with the Porsche System Tester II No. 9588:
- MOST bus switch on
- MOST bus switch off
- MOST power reduction start
- MOST power reduction stop
- Switch output on
- Switch output off
- Volume - minimum value
- Volume - centre position
- Volume - maximum value
- Front fader
- Centre fader
- Rear fader
- Left balance
- Centre balance
- Right balance
- Bass - minimum value
- Bass - centre position
- Bass - maximum value
- Treble - minimum value
- Treble - centre position
- Treble - maximum value
- Open MOST switch
- MOST switch closed
- Mute off
- Mute on

This instruction does not apply to the following points:
- MOST bus switch
- MOST power reduction

NOTE: The activated drive link is automatically switched off after approximately 20 seconds.

Telephone/Telematics
The telephone/telematics is available as an optional feature and is linked to the PCM2 via the optical waveguide.

Tuner
The tuner is part of the PCM2 (on the mainboard)

Unlock Counter
Interruptions occur in the system if perfect communication is no longer possible. If the relevant threshold values are exceeded, an entry is recorded in the appropriate control module and the 'unlock counter' is incremented.

External Amplifier
The external amplifier (Harman or BOSE) is available as an optional feature and is linked to the PCM2 via the optical waveguide.

Internal Amplifier
The tuner is part of the PCM2 (on the mainboard).

Wake-Up Function
In an idle state, all control modules that are connected to the MOST are in sleep mode. When the PCM2 is switched on, a 'wake-up signal' is sent via the gateway. This signal is answered by the MOST control modules that are connected via the optical MOST.
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