Communications Control Module: Testing and Inspection

WM 919025 Eliminating symptoms in body interior: Programming telephone control unit (telephone sound quality)

General information

Symptom

Sound quality of hands-free telephone

Causes and remedial action

Cause

If you make calls using the hands-free telephone, the quality of the transmitted sound can be reduced as a result of external factors (e.g. road surface, bad reception in mobile telephone networks) or can be distorted at times (Mickey Mouse effect).

Remedial action

To improve the quality of the transmitted sound, the parameters for the hands-free facility can be adapted using alternative telephone software.

In the event of a complaint, update the telephone control unit software with the update CD using PCM2.1.

Tools and materials

Tools

Battery charger





Programming telephone control unit

CAUTION

Malfunctions in PCM2.1 integrated system - data loading operation interrupted

- If the data loading operation is interrupted due to a voltage drop, malfunctions can occur in the PCM2.1 integrated system.

-> Connect a suitable battery charger to the vehicle battery before you begin work.

1. Connect a battery charger to the vehicle electrical system battery.
2. Switch on ignition.
3. Switch on PCM2.1 if necessary by pressing the left rotary knob ( -item 1- ).





Figure 1

4. Press the Eject button ( -item 3- ) and remove audio CD from the CD slot ( -item 4- ), if one was inserted.
5. Insert the PCM2.1 Telephone Update CD-ROM, Part No. 000.043.205.46.008, into the CD slot ( -item 4- ).
The message "Single CD: checking data CD" appears in the footer of the PCM2.1 display ( -item 5- ) when you insert the CD.
When the CD-ROM check is complete, the query "Update software to version Model Improvements C Telephone V7.22.5?" appears in the main section of the PCM2.1 display ( -item 6- ).
The option "Yes" is already pre-selected.
6. Press the right rotary knob ( -item 7- ) to confirm the "Yes" option and start the software update.
During the update process, the following messages are displayed in the main section of the PCM2.1 display ( -item 6- ):
- Telephone update
- Device 1 of 1
- Update to Version V7.22.5 is being performed
- Status OK
A progress bar shows the progress of the loading operation from 0% to 100%.
When the update to version V7.22.5 is complete, the message "Update successful" appears in the main section of the PCM2.1 display ( -item 6- ).
7. Press the Eject button ( -item 3- ) and remove the Telephone Update CD from the CD slot ( -item 4- ).
8. If you removed an audio CD from the CD slot of the PCM2.1 operator control unit, re-insert it.
9. Switch off ignition.
10. Disconnect battery charger.

Information

If the installed telephone software does not provide the expected improvement in sound quality, the telephone control unit must be updated to the current version using the "PCM2.1 Telephone Control Unit Software CD" (Part No. 000.043.205.46.009). To do this, repeat Steps 1-10 using the "PCM2.1 Telephone Control Unit Software CD".

Working time

91902541: Programming telephone control unit; Labor time 30 TU