PCM2 MMI
PCM2 MMI control module functionTerminating resistors in the CAN
Terminating resistors are fitted to each end of the wiring to prevent reflection on the wiring. These terminating resistors are integrated into each control module. The interconnection prevents the resistors from being measured with the ohmmeter from the outside.
CAN comfort
Communication between the 9588 Porsche System Tester II 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
The PCM2 can be coded country-specifically under the menu item 'Modify coding'.
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 encoded, 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.
Extended identification
Additional data present in the control module can be read out using this menu item.
1. Connect and start the 9588 Porsche System Tester II 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 modules menu and confirm with the [>>] key.
4. Select 'PCM2 MMI' in the PCM2 function selection and confirm with the [>>] key.
5. Select "Identification" in the PCM2 MMI function selection and confirm with the [>>] key.
6. "Diagnosis software number; PCM2 parts number" appears on the display.
7. In the PCM2 - MMI identification function selection the extended identification can be read out using the [F8] key or the [>>] key.
The following data can be read out:
- CRIN (Car Radio Identification Number)
- Date of ECU Manufacturing (YYYY;MM;DD)
- Repair Shop Code or Tester Serial Number
- System Supplier ECU Hardware Number (cw, year)
- System Supplier ECU Hardware Version Number
- System Supplier ECU Software Number (cw, year)
- System Supplier ECU Software Version Number
- Vehicle Manufacturer Diagnostic Index
- Vehicle Manufacturer ECU Hardware Number
- VIN (Vehicle Identification Number)
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 9588 Porsche System Tester II 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 modules menu and confirm with the [>>] key.
4. Select 'PCM2 MMI' in the 911 (996) PCM2 function selection and confirm with the [>>] key.
5. Select "Identification" in the 911 (996) PCM2 MMI function selection and confirm with the [>>] key.
6. "Diagnosis software number; PCM2 parts number" appears on the display.
Actual values
It is possible to read out the MOST unlock counter under the 'Actual values' menu item.
Man Machine Interface (MMI)
The MMI is part of the PCM2 (on the mainboard). It carries out the diagnostics of the ring break diagnosis line (stub cable) and the diagnostics of the optical distribution line.
MOST component check
NOTE: When there is a customer complaint or identifiable problems but no fault code entries, firstly the 'MOST component check' is to be selected in the PCM2 function selection menu and then the 'MOST system check' is to be carried out.
The MOST component check can be reached via the menu PCM2 function selection. This comprises a summary of the following check processes:
- MOST System check (ignition on.)
- Diagnosis, open circuit in distribution line (ignition on.)
- Optical performance check
- Data transmission check
- MOST system check (with engine running)
- Ring break diagnosis (with engine running)
The MOST components check 'MOST system check' is to be carried out when the display indicates 'unavailable MOST control modules'. If no fault code is stored, the '*' symbol indicates a 'varying required and actual installed components list' in the Control modules menu in front of the 'PCM2' system and in the 'PCM2 MMI function selection' in front of the selection 'MOST required installed components list'. A comparison of these two lists can determine missing components.
MOST System check (ignition on.)
This check must only be carried out when the engine is not running.
Diagnosis, open circuit in distribution line (ignition on.)
This check must only be carried out when the engine is not running.
Optical performance check
Data transmission check
MOST system check (with engine running)
Ring break diagnosis (with engine running)
MOST actual and required installed components lists
All MOST control modules that are connected to the PCM2 are entered via diagnostic tester in the 'required installed components list'. Only the MOST control modules recorded in the MOST required installed components list are activated. An 'actual installed components list' of detected devices is written and saved when the PCM2 is started.
MOST lock/MOST unlock
A lock occurs when the signal sent from the MMI via the MOST optical/ electrical is understood and answered by the connected MOST control modules. This applies a correct optical MOST signal. The lock is maintained until the signal is no longer detectable for a longer period of time (several �seconds) 'unlock'.
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 (optional).
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 (optional, 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.
The following settings can be coded:
- MOST switch open.
- MOST switch closed.
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.
MOST 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.
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.
Ring break diagnosis line
The ring break diagnosis 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.
Input signals
The following queries can be run using this menu item:
- Key code
- Increment steps
NOTE: Deactivate the 'automatic traffic announcement' before performing the diagnosis on the PCM2. If this is not done, the diagnosis will abort (only for software version < 03).
Input signals
The following queries can be run using this menu item:
- Key code
- Increment steps
NOTE: Deactivate the 'automatic traffic announcement' before performing the diagnosis on the PCM2. If this is not done, the diagnosis will abort.
Single CD
The CD player is part of the PCM2. It is used to play the audio and navigation CDs as well as to update the navigation system.
Special function
The following functions can be run using this menu item:
- Read address book
- Write to address book
- Read user data
- Write user data
- Read coding
- Write coding
- MOST actual installed components list
Voice control system (VOCS) (optional)
The VOCS (optional) 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 with 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 9588 Porsche System Tester II:
- Display colour black
- Display colour"coloured bars"
- Display colour blue
- Display colour red
- Display colour green
- Display colour white
- Set default values
- Ring break diagnosis
- Ring break line diagnosis
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)
Amplifier (internal)
Tuner
Single CD
Navigation (optional/insertion)
VOCS (voice control system) (optional/insertion)
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 optional Navigation and VOCS (optional)), which communicate electronically with each other via MOST. Data is transferred outside of the PCM2 via the optical MOST.
Telephone/telematics (optional)
The telephone/telematics feature (optional) 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).
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 modules connected to the MOST are in sleep mode if the PCM2 is deactivated. When the PCM2 is switched on, a 'light' is switched on via the MMI. It is reinforced and passed on by the MOST control modules that are connected.