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Home >> Porsche >> 2004 >> 911 Carrera Coupe (996) F6-3.6L >> Repair and Diagnosis >> Relays and Modules >> Relays and Modules - Accessories and Optional Equipment >> General Module >> Testing and Inspection >> Component Tests and General Diagnostics >> PCM2/CDR23 Gateway >> PCM2 Gateway Control Module Function

PCM2 Gateway Control Module Function



PCM2 Gateway Control Module Function

Terminating Resistors On The CAN
A terminating resistor is fitted to each end of the wiring to prevent reflection on the wiring. These terminating resistors are integrated into two control modules.

Audio Tests
The following functions can be run using this menu item:
- Manual single selection
- Automatic test

Menu item Function

- Manual single selection This menu item allows you to carry out a manual audio test on vehicles with no external amplifier.
- Connect and start the Porsche System Tester II No. 9588 and switch on the ignition.
- Select "911 (996)" in the Vehicle type menu and confirm with the >> key.
- Select "PCM" in the Control units menu and confirm with the >> key.
- Select "PCM2 GW" in the 911 (996) PCM2 function selection and confirm with the >> key.
- Select "Audio tests" in the PCM2 GW function selection and confirm with the >> key.
- Select "Manual single selection" in the PCM2 GW audio tests function selection and confirm with the >> key.
- Select the required loudspeaker system and confirm with the >> key.

The following selection is available:
- front left, test frequency 1 kHz
- front right, test frequency 1 kHz
- rear left, test frequency 1 kHz
- rear right, test frequency 1 kHz
- F5 Boost volume
- F6 Lower volume
- F8 Start test
- Automatic test This menu item allows you to carry out an automatic audio test on vehicles with no external amplifier.
- Connect and start the Porsche System Tester II No. 9588 and switch on the ignition.
- Select "911 (996)" in the Vehicle type menu and confirm with the >> key.
- Select "PCM" in the Control units menu and confirm with the >> key.
- Select "PCM2 GW" in the 911 (996) PCM2 function selection and confirm with the >> key.
- Select "Audio tests" in the PCM2 GW function selection and confirm with the >> key.
- Select the menu item "Automatic test" and confirm with the >> key.

The test sequence is automatic.

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 Table










Coding
Under the "Modify coding" menu item, the PCM2 code can be extracted and the PCM2 coded on a vehicle-specific and country-specific basis.

Menu item Function

- Units You can code the relevant units country specifically using this menu item.
- Connect and start the Porsche System Tester II No. 9588 and switch on the ignition.
- Select "911 (996)" in the Vehicle type menu and confirm with the >> key.
- Select "PCM" in the Control units menu and confirm with the >> key.
- Select "PCM2 GW" in the 911 (996) PCM2 function selection menu and confirm with the >> key.
- Select "Coding" in the PCM2 GW function selection menu and confirm with the >> key.
- Select "Units" in the PCM2 GW coding menu and confirm with the >> key.
- Select "the relevant units" from the menu item that is displayed and code them with the F8 key.

The following selection is available:
- Metric, RoW (degree C, litre, km)
- UK English (degree C, gallon, mph)
- US English (degree F, gallon, mph)
- Vehicle type vehicle
coding Under this menu item, the PCM2 GW corresponding to the vehicle type can be coded.
- Connect and start the Porsche System Tester II No. 9588 and switch on the ignition.
- Select "911 (996)" in the Vehicle type menu and confirm with the >> key.
- Select "PCM" in the Control unit menu and confirm with the >> key.
- Select "PCM2 GW" in the 911 (996) PCM2 function selection and confirm with the >> key.
- Select "Coding" in the PCM2 GW function selection and confirm with the >> key.
- Select "Vehicle type vehicle coding" in the Coding menu and confirm with the >> key.
- Select "911 (996)" in the menu and code with the F8 key.
- Vehicle version vehicle
coding Under this menu item, the PCM2 GW corresponding to the vehicle version can be coded.
- Connect and start the Porsche System Tester II No. 9588 and switch on the ignition.
- Select "911 (996)" in the Vehicle type menu and confirm with the >> key.
- Select "PCM" in the Control unit menu and confirm with the >> key.
- Select "PCM2 GW" in the 911 (996) PCM2 function selection and confirm with the >> key.
- Select "Coding" in the PCM2 GW function selection and confirm with the >> key.
- Select "Vehicle version vehicle coding" in the PCM2 GW coding and con- firm with the >> key.
- Select the relevant version "Coupe, Cabrio, Targa" in the menu and code with the F8 key.
- Right/left-hand drive
vehicle coding Under this menu item, the PCM2 GW corresponding to the vehicle version can be coded.
- Connect and start the Porsche System Jester II No. 9588 and switch on the ignition.
- Select "911 (996)" in the Vehicle type menu and confirm with the >> key.
- Select "PCM" in the Control units menu and confirm with the >> key.
- Select "PCM2 GW" in the PCM2 function selection and confirm with the >> key.
- Select "Coding" in the PCM2 GW function selection and confirm with the >> key.
- Select "Right/left-hand drive vehicle coding" in the PCM2 GW coding function selection and confirm with the >> key.
- Select "Right or left-hand drive" in the menu corresponding to the vehicle equipment and code with the F8 key.
- Air conditioning
with/without Under this menu item, the PCM2 GW corresponding to the air conditioning equipment can be coded.
- Connect and start the Porsche System Tester II No. 9588 and switch on the ignition.
- Select "911 (996)" in the Vehicle type menu and confirm with the >> key.
- Select "PCM" in the Control units menu and confirm with the >> key.
- Select "PCM2 GW" in the PCM2 function selection and confirm with the >> key.
- Select "Coding" in the PCM2 GW function selection and confirm with the >> key.
- Select "Air conditioning with/without" in the PCM2 GW coding function selection and confirm with the >> key.
- Select "Air conditioning With/without" corresponding to the equipment in the Modify PCM2 GW coding function selection 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 "911 (996)" in the Vehicle type menu and confirm with the >> key.
- Select "PCM" in the Control units menu and confirm with the >> key.
- Select "PCM2 GW" in the PCM2 function selection and confirm with the >> key.
- Select "Coding" in the PCM2 GW function selection and confirm with the >> key.
- Select "Country coding" in the PCM2 GW Coding function selection and confirm with the >> key.
- Select "the relevant country coding" from the menu item that is displayed and code it with the F8 key.
- MOST switch If the PCM2 is operated without additional MOST control modules, the MOST switch must be closed. The MOST switch must only remain open if MOST control units are connected.
Using this menu item, you can code the MOST switch corresponding to the vehicle equipment.
- Connect and start the Porsche System Tester II No. 9588 and switch on the ignition.
- Select "911 (996)" in the Vehicle type menu and confirm with the >> key.
- Select "PCM" in the Control units menu and confirm with the >> key.
- Select "PCM2 GW" in the PCM2 function selection and confirm with the >> key.
- Select "Coding" in the PCM2 GW function selection and confirm with the >> key.
- Select "MOST switch open/closed" in the PCM2 GW coding function selection and confirm with the >> key.
- Select "MOST switch open/MOST switch closed" from the menu displayed and code with the F8 key.

The following selection is available:
- MOST switch open
- MOST switch closed
- PCM2 code It is possible to code the PCM2 code under this menu item after replacing the PCM2.
- Connect and start the Porsche System Tester II No. 9588 and switch on the ignition.
- Select "911 (996)" in the Vehicle type menu and confirm with the >> key.
- Select "PCM" in the Control units menu and confirm with the >> key.
- Select "PCM2 GW" in the PCM2 function selection and confirm with the >> key.
- Select "Coding" in the PCM2 GW function selection and confirm with the >> key.
- Select "PCM2 code" in the PCM2 GW coding function selection.
- Take the PCM2 code from IPAS, enter it and code it with the F8 key.
- Production mode The PCM2 is set to the "Production mode ON" low-power mode in the factory and this must be switched off when put into service.
- Connect and start the Porsche System Tester II No. 9588 and switch on the ignition.
- Select "911 (996)" in the Vehicle type menu and confirm with the >> key.
- Select "PCM" in the Control units menu and confirm with the >> key.
- Select "PCM2 GW" in the PCM2 function selection and confirm with the >> key.
- Select "Coding" in the PCM2 GW function selection and confirm with the >> key.
- Select "Production mode" in the PCM2 GW Coding function selection and confirm with the >> key.
- Select "Production mode OFF" from the menu item displayed and code it with the F8 key.

The following selection is available:
- Production mode on
- Production mode off
- Tuner parameters Using this menu item, you can code the tuner parameters (country-specific tuner setting) for the country of registration.
- Connect and start the Porsche System Tester II No. 9588 and switch on the ignition.
- Select "911 (996)" in the Vehicle type menu and confirm with the >> key.
- Select "PCM" in the Control units menu and confirm with the >> key.
- Select "PCM2 GW" in the 911 (996) PCM2 function selection and confirm with the >> key.
- Select "Coding" in the PCM2 GW function selection and confirm with the >> key.
- Select "Tuner parameters" in the PCM2 GW Coding function selection and confirm with the >> key.
- Select the country code for the country of registration 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 recorded.

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 checked at regular intervals during communication with the control modules via the electrical/optical 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. Diagnostic and useful data is exchanged with the 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/insertion)
- Man Machine Interface (MMI)
- Single CD
- Media Oriented Systems Transport (MOST), external bus (optical)

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 "911 (996)" in the Vehicle type menu and confirm with the >> key.
3. Select "PCM" in the Control units menu and confirm with the >> key.
4. Select "PCM2 GW" in the PCM2 function selection and confirm with the >> key.
5. Select "Identification" in the PCM2 GW function selection and confirm with the >> key.
6. "Diagnosis software number; PCM2 part 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 "911 (996)" in the Vehicle type menu and confirm with the >> key.
- Select "PCM" in the Control units menu and confirm with the >> key.
- Select "PCM2 GW" in the PCM2 function selection and confirm with the >> key.
- Select "Actual values" in the PCM2 GW function selection and confirm with the >> key.
- Select "Unlock counter" in the PCM2 GW actual values function selection and confirm with 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; this results in a "lock (connection)". The lock is maintained until the signal disappears, i.e. an "unlock" occurs.

Man Machine Interface (MMI)
The MMI is part of the PCM2 (on the main board). It runs the gateway commands via the wake-up signal line and the distribution line diagnosis. If control modules fail, this is reported to the gateway and saved there.

MOST Actual And Required Installed Components Lists
All MOST control modules that are connected to the PCM2 are entered in the "required installed components list". The "actual installed components list" is compared with the "required installed components list" each time the PCM2 is started. If an "installed MOST control module" is not reported, the MOST is switched off optically and a fault is recorded in the gateway.

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 VOCS 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 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 inserted in the PCM2 as an option. After the insertion, an electronic switch is opened automatically and the module is integrated into the MOST ring.

Input Signals
The following queries can be run using this menu item:
- 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

- Registry startup status 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 "911 (996)" in the Vehicle type menu and confirm with the >> key.
- Select "PCM" in the Control units menu and confirm with the >> key.
- Select "PCM2 GW" in the PCM2 function selection and confirm with the >> key.
- Select "Input signals" in the PCM2 GW function selection and confirm with the >> key.
- Select "Startup status registry" in the PCM2 GW input signals function selection and confirm with the >> key.
- Read out values from the display field.
- Internal ring startup
status Under this menu item, the internal ring startup status can be read out during troubleshooting.
- Connect and start the Porsche System Tester II No. 9588 and switch on the ignition.
- Select "911 (996)" in the Vehicle type menu and confirm with the >> key.
- Select "PCM" in the Control units menu and confirm with the >> key.
- Select "PCM2 GW" in the PCM2 function selection and confirm with the >> key.
- Select "Input signals" in the PCM2 GW function selection and confirm with the >> key.
- Select "Startup status" in the PCM2 GW input signals function selection and confirm with the >> key.
- Read out values from the display field.
- "Internal ring startup status" internal MOST (electrical) is functional.
- External ring startup
status Under this menu item, the external ring startup status can be read out during troubleshooting.
- Connect and start the Porsche System Tester II No. 9588 and switch on the ignition.
- Select "911 (996)" in the Vehicle type menu and confirm with the >> key.
- Select "PCM" in the Control units menu and confirm with the >> key.
- Select "PCM2 GW" in the PCM2 function selection and confirm with the >> key.
- Select "Input signals" in the PCM2 GW function selection and confirm with the >> key.
- Select "Startup status" in the PCM2 GW input signals function selection and confirm with the >> key.
- Read out values from the display field.
- "External ring startup status" internal MOST (electrical) is functional.
- "External ring startup status" external MOST (optical) is functional.

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

Special Function
The following functions can be run using this menu item:
- Antenna diversity test
- Set tuner frequency
- Reset
- Wake-up sequence of the MOST system

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

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

The following drive links can be activated with the Porsche System Tester II No. 9588:
- Left balance
- Central balance
- Right balance
- Bass - maximum value
- Bass - minimum value
- Bass - centre position
- Rear fader
- Middle fader
- Front fader
- MOST power reduction
- MOST switch
- Mute
- MOST bus switch
- Output switch
- Treble - minimum value
- Treble - centre position
- Treble - maximum value
- Volume - maximum value
- Volume - minimum value
- Volume - centre position

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

PCM2 Control Module (Head Unit)
The PCM2 control module (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/insertion)
VOCS (voice control system) (optional/insertion)
Wake-up and distribution line diagnosis control
Controller Area Network (CAN) Comfort
MOST switch

External:
External amplifier (optional, Harman or BOSE)
CD changer (CDC), (optional)
Telephone/telematics (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 electronically via the MOST. Data is transferred outside of the PCM2 via the optical MOST.

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

Tuner
The tuner is part of the PCM2 (on the main board).

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 internal amplifier is part of the PCM2 (installed on the main board).

Wake-up Function
All control units connected to the MOST are in sleep mode if the PCM2 is deactivated. When the PCM2 is switched on, a "wake-up signal" is sent via the MMI. This signal is answered by the MOST control modules that are connected via the optical MOST. The check-back signals are stored as a MOST actual installed components list by the MMI and are compared with the MOST required installed components list. If a control unit is not detected, this will be reported to the gateway and stored. The MOST switch will then close and control units connected to the optical MOST will be switched off again. If the MOST actual installed components list matches the MOST required installed components list and the checkbacks occur within 40 ms, communication will be established with all control units. The MOST switch will now be held open.
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