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Data Transfer Fault



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.

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 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 modules 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
- Unlock counter

Function
Under this menu item, it is possible to check the electrical and optical MOST during troubleshooting.
- Connect and start the Porsche System Tester II 9588 and switch on the ignition.
- Select 911 (996) in the Vehicle type menu and confirm with the >> key.
- Select PCM in the Control modules 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.

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 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 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, ring break diagnosis (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.

Menu item
- MOST System check (ignition on.)

Function
Using this menu item, a MOST system check can be carried out with the ignition on. The following checks are carried out automatically and their results are displayed.
- Gateway start-up condition is read out.
- MOST installed components list (required and actual installed components list) is analysed.
- Start the ring break diagnosis.
- The results are displayed by the Porsche System Tester II 9588.
- Connect and start the Porsche System Tester II 9588 and switch on the ignition.
- Select 911 (996) in the Vehicle type menu and confirm with the >> key.
- Select PCM2 in the Control modules menu and confirm with the >> key.
- Select MOST components check in the PCM2 function selection and confirm with the >> key.
- Select MOST system check (ignition on) in the 911 (996) PCM MOST components check function selection and confirm with the >> key.

Diagnosis, open circuit in distribution line (ignition on.)
This check must only be carried out when the engine is not running.

Menu item
- Diagnosis, ring break diagnosis (ignition on.)

Function
The ring break diagnosis carries out the following checks:
- Gateway start-up condition is read out.
- MOST installed components list (required and actual installed components list) is analysed.
- Start the ring break diagnosis.
- The results are displayed by the Porsche System Tester II 9588.
- Connect and start the Porsche System Tester II 9588 and switch on the ignition.
- Select 911 (996) in the Vehicle type menu and confirm with the >> key.
- Select PCM2 in the Control modules menu and confirm with the >> key.
- Select MOST components check in the PCM2 function selection and confirm with the >> key.
- Select Ring break diagnosis (top) in the 911 (996) PCM MOST components check function selection and confirm with the >> key.
- Follow the Tester instructions.

Optical performance check

Menu item
- Optical performance check

Function
The optical performance check allows the performance of the MOST to be checked optically. The following checks are carried out automatically:
- MOST installed components list (required and actual installed components list) is analysed.
- External MOST components display.
- Carrying out the performance check.
- The result is displayed by the tester.
- Connect and start the Porsche System Tester II 9588 and switch on the ignition.
- Select 911 (996) in the Vehicle type menu and confirm with the >> key.
- Select PCM2 in the Control modules menu and confirm with the >> key.
- Select MOST components check in the PCM2 function selection and confirm with the >> key.
- Select Optical performance check in the 911 (996) PCM2 MOST components check function selection and confirm with the >> key.
- Follow the Tester instructions.

Data transmission check

Menu item
- Data transmission check

Function
Using this menu item, the quality of the data transmission can be assessed. This is a counter which leads to an increase in the value if faults occur within a certain time period. The check is carried out continuously at predetermined intervals.
- Connect and start the Porsche System Tester II 9588 and switch on the ignition.
- Select 911 (996) in the Vehicle type menu and confirm with the >> key.
- Select PCM2 in the Control modules menu and confirm with the >> key.
- Select MOST components check in the PCM2 function selection and confirm with the >> key.
- Select Data transmission check in the 911 (996) PCM2 MOST components check function selection and confirm with the >> key.

MOST system check (with engine running)

Menu item
- MOST system check (with engine running).

Function
Using this menu item, a MOST system check can be carried out with the ignition on. The following checks are carried out automatically and their results are displayed.
- Gateway start-up condition is read out.
- MOST installed components list (required and actual installed components list) is analysed.
- Ring line diagnosis.
- Connect and start the Porsche System Tester II 9588 and switch on the ignition.
- Select 911 (996) in the Vehicle type menu and confirm with the >> key.
- Select PCM2 in the Control modules menu and confirm with the >> key.
- Select MOST components check in the PCM2 function selection and confirm with the >> key.
- Select MOST system check (bottom) in the 911 (996) PCM2 MOST components check function selection and confirm with the >> key.
- Follow the Tester instructions.

Whenever there are several ring breaks, the 1st ring break is displayed in the following order:
- PCM2 Gateway > external amplifier.
- External amplifier > CD changer.
- CD changer > telephone.
- Telephone > PCM2 MMI. is displayed. Then the check is terminated.
- Start the optical performance check.

Ring break diagnosis (with engine running)

Menu item
- Ring break diagnosis (with engine running).

Function
Using this menu item, a ring break diagnosis can be carried out (with the engine running).
- Connect and start the Porsche System Tester II 9588 and switch on the ignition.
- Select 911 (996) in the Vehicle type menu and confirm with the >> key.
- Select PCM2 in the Control modules menu and confirm with the >> key.
- Select PCM2 GW in the PCM2 function selection and confirm with the >> key.
- Select MOST components check in the PCM2 GW function selection and confirm with the >> key.
- Select Ring break diagnosis (when the engine is running) in the 911 (996) PCM2-GW MOST components check function selection and confirm with the >> key.

MOST lock/MOST unlock
A lock occurs when the signal sent from the MMI via the wake-up/ring break diagnosis 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.

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:
- 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 (only for software version < 03).

Menu item
- Registry startup status.

Function
It is displayed under this menu item that installed MOST control modules can be read out from the actual installed components list.
- Connect and start the Porsche System Tester II 9588 and switch on the ignition.
- Select 911 (996) in the Vehicle type menu and confirm with the >> key.
- Select PCM in the Control modules 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 Start-up status registry in the PCM2 GW input signals function selection and confirm with the >> key.
- Read out values from the display field.

Menu item
- Internal ring startup status.

Function
Under this menu item, the internal ring startup status can be read out during troubleshooting.
- Connect and start the Porsche System Tester II 9588 and switch on the ignition.
- Select 911 (996) in the Vehicle type menu and confirm with the >> key.
- Select PCM in the Control modules 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 Start-up 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.

Menu item
- External ring startup status.

Function
Under this menu item, the external ring startup status can be read out during troubleshooting.
- Connect and start the Porsche System Tester II 9588 and switch on the ignition.
- Select 911 (996) in the Vehicle type menu and confirm with the >> key.
- Select PCM in the Control modules 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 Start-up 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 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:
- Antenna diversity test.
- Set tuner frequency
- Reset.
- Wakeup sequence of the MOST system.

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 Porsche System Tester II 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.
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