Volkswagen Workshop Service and Repair Manuals

There are control units which must not be coded (engine control unit MSA12) and control units which must be coded (engine control unit MSA15).

If the appropriate code for the vehicle is not displayed or if the control unit has been renewed, the control unit must be coded as follows.

Special tools, testers, measuring instruments and auxiliary items required

• ◆ Fault reader V.A.G 1551 or vehicle system tester V.A.G 1552 with cable V.A.G 1551/3

Work sequence

• ‒ Connect fault reader V.A.G 1551 (V.A.G 1552) and select engine electronics control unit with the "Address word" 01. When doing this the ignition must be switched on.
  (Connecting fault reader and selecting engine electronics control unit .)

Control unit identification of MSA12

• ◆ There are no zeros in front of the type of gearbox (MG or AG).
• ◆ The software version begins with a letter.

Externally the MSA12 can be recognised by the plastic housing.

Control unit identification of MSA15

• ◆ There are two zeros in front of gearbox version (SG or AG) or G if the vehicle is equipped with a cruise control system (CCS).
• ◆ The software version is made up of a 4 digit number, e.g. 0602 or a capital letter-number combination, e.g. KD03.
• ◆ The display KDxx means that the engine control unit is an exchange engine control unit. See engine control unit print-out for coding to be entered.

Note:

Externally the MSA15 is recognised by the aluminium housing.

• ‒ Press ⇒key.

• ‒ Press keys 0 and 7 for the function "Code control unit" and confirm entry with Q key.

Coding when replacing a MSA 12 engine control unit with a MSA 15 engine control unit

• ‒ Code the exchange engine control unit MSA15 according to table.

Example:

Part number of old control unit MSA12:
- 028 906 021 AK

Part number of exchange control unit MSA15:
- 028 906 021 FF

Coding of exchange engine control unit MSA15:
- 00012

• ‒ Enter the appropriate code number for this vehicle and confirm with Q key.

Coding engine control unit MSA 15 (without display "KDxx" in control unit identification)

• ‒ Enter the appropriate code number for this vehicle and confirm with Q key.

• ‒ Press ⇒key.
• ‒ Press keys 0 and 6 for the "End data transfer" function and confirm input with the Q key.
• ‒ Switch ignition off and then on again.

Note:

The coding entered will be activated by switching the ignition off and then on again. If after entering the valid code the ignition is not switched off and on again, the fault "Control unit incorrectly coded" in the fault memory cannot be erased.

• ‒ Erasing fault memory => Page 01-33
• ‒ Activating cruise control system

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