MOST Component Check

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

Menu item Function

- Data transmission check 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 9588 Porsche System Tester II and switch on the ignition.
- Select '911 (996)' in the Vehicle type menu and confirm with the [>>] key.
- Select 'CDR23' in the Control units menu and confirm with the [>>] key.
- Select 'MOST component check' in the CDR23 function selection and confirm with the [>>] key.
- Select"Data transmission check" in the 911 (996) CDR23 MOST component check function selection and confirm with the [>>] key.

MOST system check (with engine running)

Menu item Function

- MOST system check Using this menu item, a MOST system check
(with the engine running) can be carried out with 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 9588 Porsche System Tester II and switch on the ignition.
- Select '911 (996)' in the Vehicle type menu and confirm with the [>>] key.
- Select 'CDR23' in the Control units menu and confirm with the [>>] key.
- Select 'MOST component check' in the CDR23 function selection and confirm with the [>>] key.
- Select "MOST system check (bottom)" in the 911 (996) CDR23 MOST component check function selection and confirm with the [>>] key.
- Follow the instructions on the Tester.

Whenever there are several ring breaks, the first ring break is displayed in the following order:
- PCM2 Gateway [>] external amplifier
- External amplifier [>] CD changer
- CD changer [>] telephone
- Telephone [>] PCM2 MMI

Then, the check is terminated.
- Start the optical performance check.

Ring break diagnosis (with engine running)

Menu item Function

- Ring break diagnosis (with Using this menu item, a ring break
(with engine running) diagnosis can be carried out (with the engine running).
- Connect and start the 9588 Porsche System Tester II and switch on the ignition.
- Select '911 (996)' in the Vehicle type menu and confirm with the [>>] key.
- Select 'CDR23' in the Control units menu and confirm with the [>>] key.
- Select 'MOST component check' in the CDR23 function selection and confirm with the [>>] key.
- Select "Ring break diagnosis (with engine running)" in the 911 (996) CDR23 MOST component check function selection and confirm with the [>>] key.

Ring break diagnosis (with engine running)

- Ring break diagnosis Using this menu item, a ring break
lead (with engine running) diagnosis lead can be checked (with the engine running).
- Connect and start the 9588 Porsche System Tester II and switch on the ignition.
- Select '911 (996)' in the Vehicle type menu and confirm with the [>>] key.
- Select 'CDR23' in the Control units menu and confirm with the [>>] key
- Select 'MOST component check' in the CDR23 funtion selection and confirm with the [>>] key.
- Select"Ring break diagnosis lead (with engine running)" in the 911 (996) CDR23 MOST component check function selection and confirm with the [>>] key.