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Checking Most Components



Control Unit Function (part 2)

Checking MOST Components
The following checks are possible under this menu item:
- MOST system check
- Distribution breakage diagnosis
- Distribution breakage diagnosis lead
- Optical power check

NOTE: The engine must not be started during the automatic check. Follow the instructions of the Porsche System Tester II No. 9588.

The check procedures occur automatically. The check results are displayed.

Menu Item Function

- MOST system check Under this menu you can carry out an automatic MOST system check.
- Connect and start the Porsche System Tester II No. 9588 and switch on the ignition.
- Select '911 Turbo (996)' in the vehicle type menu and confirm with the ->| key.
- Select 'PCM' in the control module selection menu and confirm with the >> key.
- Select 'MOST component check' in the 911 Turbo (996) CDR23 function selection menu and confirm with the >> key.
- Select 'MOST system check' in the CDR23 MOST component check menu and confirm with the >> key
- The check results are displayed.

Before replacing control units, optical waveguide and distribution breakage diagnosis lead must be checked.

- Ring breakage
diagnosis Under this menu item you can carry out an automatic distribution breakage diagnosis.
- Connect and start the Porsche System Tester II No. 9588 and switch on the ignition.
- Select '911 Turbo (996)' in the vehicle type menu and confirm with the ->| key.
- Select 'PCM' in the control module selection menu and confirm with the >> key.
- Select 'MOST component check' in the 911 Turbo (996) CDR23 function selection menu and confirm with the >> key.
- Select 'MOST distribution breakage diagnosis' in the CDR23 MOST component check menu and confirm with the >> key
- The check results are displayed.

Before replacing control units, optical waveguide and distribution breakage diagnosis lead must be checked.

- Distribution breakage
diagnosis lead Under this menu item you can carry out an automatic check of the distribution lead breakage diagnosis line.
- Connect and start the Porsche System Tester II No. 9588 and switch on the ignition.
- Select '911 Turbo (996)' in the vehicle type menu and confirm with the ->| key.
- Select 'PCM' in the control module selection menu and confirm with the >> key.
- Select 'MOST component check' in the 911 Turbo (996) CDR23 function selection menu and confirm with the >> key.
- Select 'MOST distribution breakage diagnosis lead' in the CDR23 MOST component check menu and confirm with the >> key
- The check results are displayed.

Before replacing control units, optical waveguide and distribution breakage diagnosis lead must be checked.

- Optical power check Using this menu item, you can read out the transmission fault.
- Connect and start the Porsche System Tester II No. 9588 and switch on the ignition.
- Select '911 Turbo (996)' in the vehicle type menu and confirm with the ->| key.
- Select 'PCM' in the control module selection menu and confirm with the >> key.
- Select 'MOST component check' in the 911 Turbo (996) CDR23 function selection menu and confirm with the >> key.
- Select 'optical power check' in the CDR23 MOST component check menu and confirm with the >> key
- The check results are displayed.

Before replacing control units, optical waveguide and distribution breakage diagnosis lead must be checked.

MOST - Optical
MOST signals are transferred optically via the optical waveguide to the MOST control modules that are installed externally.

The CDR23 gateway node represents the connection to CAN Comfort. The optical waveguide creates the connection to the nodes in the external MOST control modules such as external amplifiers and/or CD changers (depending on the equipment).

Input Signals
The following queries can be run using this menu item:
- Keys code
- Condition of optical check
- Parameter tuner
- NDV (Noise-dependent volume increase)

NOTE: Deactivate the 'automatic traffic announcement' before performing the diagnosis on the CDR23. If this is not done, the system will crash.

Menu Item Function

- Keys code Under this menu item, it is possible to check the function of the operating keys of the CDR23.
- Connect and start the Porsche System Tester II No. 9588 and switch on the ignition.
- Select '911 Turbo (996)' in the vehicle type menu and confirm with the ->| key.
- Select 'PCM' in the control module selection menu and confirm with the >> key.
- Select 'CDR23' in the 911 Turbo (996) CDR23 function selection menu and confirm with the >> key.
- Select 'input signals' in the CDR23 function selection menu and confirm with the >> key.
- Select "MOST component check" in the 911 Turbo (996) CDR23 function selection menu and confirm with the >> key.
- If it functions correctly, the respective button code is displayed when the CDR23 buttons are actuated.

- Condition of optical
check This menu item enables the result of the optical check to be read out.
- Connect and start the Porsche System Tester II No. 9588 and switch on the ignition.
- Select '911 Turbo (996)' in the vehicle type menu and confirm with the ->| key.
- Select 'PCM' in the control module selection menu and confirm with the >> key.
- Select 'CDR23' in the 911 Turbo (996) CDR23 function selection menu and confirm with the >> key.
- Select 'input signals' in the 911 Turbo (996) CDR23 function selection menu and confirm with the >> key.
- Select "condition of optical power check" in the CDR23 input signals menu and mark with the > key and confirm with the >> key.
- The result can be read out.

- Tuner parameter This menu item enables the respective country code of the tuner to be read out.
- Connect and start the Porsche System Tester II No. 9588 and switch on the ignition.
- Select '911 Turbo (996)' in the vehicle type menu and confirm with the ->| key.
- Select 'PCM' in the control module selection menu and confirm with the >> key.
- Select 'CDR23' in the 911 Turbo (996) CDR23 function selection menu and confirm with the >> key.
- Select 'input signals' in the 911 Turbo (996) CDR23 function selection menu and confirm with the >> key.
- Mark "tuner parameter" in the 911 Turbo (996) CDR23 input signals menu with the > key and confirm with the >> key.
- The country code currently entered is displayed in the CDR23 tuner parameter menu.

- NDV (Noise-dependent
volume increase) This menu item enables the coded value of the NDV to be read out.
- Connect and start the Porsche System Tester II No. 9588 and switch on the ignition.
- Select '911 Turbo (996)' in the vehicle type menu and confirm with the ->| key.
- Select 'PCM' in the control module selection menu and confirm with the >> key.
- Select 'CDR23' in the 911 Turbo (996) CDR23 function selection menu and confirm with the >> key.
- Select 'input signals' in the 911 Turbo (996) CDR23 function selection menu and confirm with the >> key.
- Select and mark "NDV (noise-independent volume boost)" in the 911 Turbo (996) CDR23 input signals menu with the > key and confirm with the >> key.
- The currently coded value is displayed in the 911 Turbo (996) CDR23 noise-independent volume boost menu.

Single CD
The CD player is part of the CDR23.

Drive Links
This menu item enables the drive links of the CDR23 to be activated. This allows the functioning of the drive links to be assessed quickly with the Porsche System Tester II No. 9588.

The following drive links can be activated:
- Display test all on
- Display check

Menu Item Function

- Display test all on This menu item enables the functioning of the CDR23 display segments to be checked.
- Connect and start the Porsche System Tester II No. 9588 and switch on the ignition.
- Select '911 Turbo (996)' in the vehicle type menu and confirm with the ->| key.
- Select 'PCM' in the control module selection menu and confirm with the >> key.
- Select 'CDR23' in the 911 Turbo (996) CDR23 function selection menu and confirm with the >> key.
- Select 'drive links' in the 911 Turbo (996) CDR23 function selection menu and confirm with the >> key.
- Mark "display test all on" in the CDR23 drive links menu with the > key and confirm with the >> key.
- The test is started by operating the F8 key.
- All segments are activated on the CDR23 display and their functioning can be checked.

CDR23 Control Module
The CDR23 is installed in the vehicle with and without amplifier (internal).

The CDR23 with amplifier (internal) is used if no external amplifier (Harman or BOSE) is installed.

The CDR23 without amplifier (internal) is used if a sound package is installed.

NOTE: If there is no external amplifier (Harman or BOSE) installed on the CDR23 and if there is no CD changer installed, an optical wave guide must be projected on the optical wave guide bushing.

The CDR23 control module includes the following components:

Internal:
CDR23 GW
Internal amplifier (optional, depending on the equipment)
Tuner
Single CD
Wake-up and diagnosis distribution line control
Controller Area Network (CAN) Comfort

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

Tuner
The tuner forms part of the PCM2 and is installed 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 CDR23 via the optical waveguide.

Internal Amplifier
The optional internal amplifier (according to equipment) is a component of the PCM2 (installed on the mainboard).

Wake-Up Function
In an idle state, all control modules that are connected to the CDR23 are in sleep mode. When the CDR23 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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