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CDR23 Control Module Function

CDR23 control module function

Terminating resistors on 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 CDR23 gateway and via the optical MOST outside the CDR23.

CD changer (CDC)
The CDC is available as an optional feature and is linked to the CDR23 via the optical waveguide.

Coding table












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















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.

Function of the components






Gateway
The gateway is integrated in the CDR23. It is a fixed component of each CDR23. It provides a connection from CAN comfort to the MOST 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)
- 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 'CDR23' in the Control units menu and confirm with the [>>] key.
4. Select 'Identification' in the 911 (996) CDR23 function selection and confirm with the [>>] key.
5. The message 'Diagnosis software number; CDR23 part number.' appears on the display.

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






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 component check

NOTE: When there are customer complaints or identifiable problems but no fault code entries, the 'MOST component check' must first be selected in the PCM2 function selection menu and then the 'MOST system check' must be carried out.

The MOST component check can be activated using the menu CDR23 function selection. This comprises a summary of the following check processes:

- Data transmission check
- MOST system check (with engine running)
- Ring break diagnosis (with engine running)
- Ring break diagnosis lead (with engine running).

The MOST component check 'MOST system check' must 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.

NOTE: The 'Reset all coding/transmission counters' function can be used to reset all fault counters that were set for all components to '0'.

Data transmission check






MOST system check (with engine running)






Ring break diagnosis (with engine running)






Ring break diagnosis (with engine running)






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 long period of time (several � seconds) 'unlock'.

NOTE: The 'Reset all coding/transmission counters' function can be used to reset all fault counters that were set for all components to '0'.

MOST - optical/electrical
MOST signals are transferred electrically within the PCM2 and optically outside of the CDR23. Internally, the CDR23 consists of one node (GW), which is installed in the device.

The data is transferred outside of the CDR23 via the optical waveguide, which creates a connection to the nodes in the external MOST control modules such as external amplifiers and/or CD changers (depending on the equipment). The gateway node represents the connection to CAN comfort.

Ring break diagnosis lead
The ring break diagnosis lead 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:

- GAL (noise-dependent loudspeaker boost -- NLB)
- Increment steps
- Key code
- Tuner parameters
- Status of the optical performance check

NOTE: Deactivate the 'automatic traffic announcement' before performing the diagnosis on the CDR23. If this is not done, the system will crash (valid only for software version < 03).









Single CD
The CD player is part of the CDR23. It is used to play audio CDs.

Drive links
Drive links of the CDR23 can be activated with this menu item. This allows the function of the drive links to be assessed very quickly using the 9588 Porsche System Tester II.
The following drive links can be activated:

- All On display test
- Loudspeaker test

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






CDR23 control module
The CDR23 is installed in the vehicle with and without amplifier (internal).
The CDR23 with amplifier (internal) is used if no sound package is installed. If there is no CD changer installed on the CDR23, an optical waveguide must be projected on the optical waveguide socket (valid only for software version < 03).
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 waveguide must be projected on the optical waveguide socket. (Valid only for software versions < 03).

The CDR23 control module includes the following components:

Internal:
CDR23 GW
Internal amplifier, optional (depending on the equipment)
Tuner
Single CD
Controller Area Network (CAN) Comfort

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

External amplifier
The external amplifier (Harman or BOSE) is available as an optional feature and is linked to the CDR23 via the optical waveguide.

Wake-up function
All MOST control modules connected to the CDR23 are in sleep mode if the CDR23 is deactivated. When the CDR23 is switched on, a 'light' is switched on. It is reinforced and passed on by the MOST control modules that are connected.
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