CDR23 - Introduction

Introduction
The database contains the diagnosis for the following system:

Cassette radio CDR23

General Instructions/Safety Instructions
The following points must be observed during vehicle diagnosis:
- After the battery is connected1 temporary memories must be reprogrammed. In the case of radio coding and tuning, the customer must be informed of decoding and the deleted tuner memory.
- Deactivate the automatic traffic announcement before beginning the diagnosis on CDR23. If this is not done, the system will crash.
- When working on the optical waveguide, please observe the Optical wave guide - MOST bus assembly.
- After troubleshooting or repairs, erase the fault memory with the Porsche System Tester II No. 9588 and carry out a test drive.
- After the test drive, read out the fault memory with the Porsche System Tester II No. 9588 again.

DANGER:
Danger of injury through triggering of driver's airbag
- Never hang the Porsche System Tester II No. 9588 over the steering wheel.

CAUTION:
Danger of damage due to improper handling of the battery and the control unit connectors
- Never disconnect battery with engine running.
- Never start engine without securely connected battery.
- Never pull off or push on plug connections for the control modules or other electronic components when the ignition is switched on.

General Information On The Fault Memory

Fault code setting conditions
Fault codes can be set in several circumstances, e.g.:
- battery disconnected
- plug connections disconnected
- power failure

In these circumstances, no fault is present in the system and the fault memory must be erased.

Fault memory info key F8
In order to be able to assess the fault exactly, the fault memory Info key F8 must be pressed. This information should be saved using the Save key F4 and printed out. If a fault code is stored with "not present" status and no other problems are present, then the fault memory must be erased.

Fault type - Frequency counter/Temperature/Voltage; Speed/Time of occurrence
Supply voltage fault
type The display shows which fault type has occurred:
- Undervoltage '< 9 V'
- Overvoltage '> 16 V'
Distribution breakage The display shows which fault type has occurred:
- Optically faulty
- Electrically faulty
Frequency counter When a fault first occurs, a fault entry is made in the fault memory and the counter is simultaneously set to 50.
If a fault is present, the counter is incremented by 1 for each "ignition on". The maximum count is 255.
The counter is decremented if the fault is no longer present. The fault memory is automatically erased when the counter reaches 0.
If the error occurs again when the counter is between 1 and 49, the counter is reset to 50.
Temperature: The value indicates the temperature (temperature sensor in the gateway) at the time the fault occurred. The temperature of the fibre optical transmitter is monitored; max 85 degree C.
Voltage The value indicates the voltage at the time the fault occurred.
Vehicle speed: The value indicates the vehicle speed at the time the fault occurred.

Vehicle hand-over

NOTE:
The CDR23 is converted into the active production delivery mode (low-current mode) in production. As known from other systems (alarm system, instrument cluster, roll-over bar), the CDR23 must be activated with the Porsche System Tester II No. 9588.
1. Connect and start the Porsche System Tester II No. 9588 and switch on the ignition.
2. Select the menu item "Special functions" and press the key >>.
3. Select the menu item "Vehicle hand-over" and press the key >>.
4. Follow the instructions of the Porsche System Tester II No. 9588.

Replacing CDR23
The CDR23 is provided in 'active production mode' as a spare part. Each time the vehicle is started, the chassis code that is stored is compared with the code in the instrument cluster. If the codes correspond, the device is operational.

As soon as a match is found, the device is operational. No further checks are carried out as long as the device is not disconnected from the vehicle electrical system.

If no match is found, the device switches off after 30 seconds and the 'PROTECTED' message appears in the display. The device is not operational. The chassis number must be coded.