MMS 311 Engine Management System

^ Both Reading and clearing procedures for the Diagnostic Trouble Code (DTC) Memory are in this article because it is necessary to read the DTC memory before the system will allow the memory to be cleared.

^ When DTC memory has been selected via the Scan Tool, all stored trouble codes will be displayed on the scan tool.
^ The DTC's are used with the Diagnostic Trouble Code Charts.
^ The DTC Charts contain: DTC Codes, Conditions, Symptoms and Possible Corrective Measures
^ DTC's are displayed one at a time or can all be printed out at once.

NOTE: If a printout of the DTC's is desired:
- Switch ON the printer using the print button, lamp in print button lights
- When the printer is switched ON stored malfunctions are automatically printed out in sequence.

^ The DTC memory cannot be erased until it has been Checked.

PROCEDURES TO CHECK MEMORY
- Connect the VAG 1551, Refer to Connecting and Operating VAG Scan Tool With MMS 311 Engine Management System
- After the display appears as shown:

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Select function XX

- Select function code.
Diagnostic Trouble Code Memory 02
- Display will appear as shown:

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02 - Check DTC Memory

- Press Q button to enter input.
- Display will appear as shown:

X DTC recognized
OR
No DTC recognized

- Indicating the number of stored malfunctions or "No DTC recognized" will be displayed.

NOTES:
^ If the printer on the VAG 1551 is turned ON the DTC's will be displayed and printed out one after the other.
^ If the printer is OFF or the VAG 1552 is being used, press the "Arrow" button the display the next DTC.

- Repair any malfunctions as necessary using the DTC Charts. With MMS 311 Engine Management System

PROCEDURES TO ERASE MEMORY
- After DTC memory has been checked leave ignition ON
- Press the "arrow" button.
- Display will appear as shown:

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Select function XX

- Select function code.
Erase DTC Memory 05
- Display will appear as shown:

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05 - Erase DTC Memory

- Press Q button to enter input.
- If memory is successfully erased the display will appear as shown:

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DTC Memory is Erased

- If Display appears as shown:

Caution DTC Memory was not checked

- The DTC Memory was not completely checked or the ignition was shut OFF before erasing the memory.
- Press the "arrow" button.

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Select function XX

Note: After repairs it maybe necessary to erase the memory due to faults store while connecting and disconnecting components.

- Test drive vehicle for 5min. or more.
- Check & Erase DTC memory.