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Servicing diesel direct injection system > < Self-diagnosis

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Diesel direct injection and glow plug system
Replacing, coding and matching engine control unit
Coding engine control unit

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.

Warning!
Always display the the control unit identification first and print out if necessary.

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
 
→ If the fault reader V.A.G 1551 displays this control unit identification, then the control unit must not be coded:
028906021C    1.9 ltr.    R4    EDC SG    D.. ⇒
Coding 0000    WSC0000
  • ◆ There are no zeros in front of the type of gearbox (MG or AG).
  • ◆ The software version begins with a letter.

Externally the MSA12 is recognised by the plastic housing.

Control unit identification of MSA15
 
→ If the fault reader V.A.G 1551 displays this control unit coding, then the control unit must be coded (example).
028906021DF 1.9l R4 EDC G00SG 0602 ⇒
Coding 00002    WSC XXXXX
  • ◆ 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 of a letter/number combination, e.g. KD09.
  • ◆ 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.

Externally the MSA15 is recognised by the aluminium housing.

  • ‒ Press ⇒key.
 
→ Indicated on display:
Rapid data transfer    HELP
Select function XX
  • ‒ Press keys 0 and 7 for the function "Code control unit" and confirm entry with Q key.
 
→ Indicated on display:
Coding control unit    Q
Enter code number xxxxx (0-00127)

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

Control unit MSA12

Exchange control unit MSA15

Coding for exchange control unit MSA 15

028 906 021 P

028 906 021 ES

00002

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.

Coding

For vehicles with

00002

Manual gearbox

00001

Automatic gearbox

 
→ The fault reader V.A.G 1551 display will show the control unit identification, e.g.:
028906021ES 1.9l R4 EDC G00SG 0602    ⇒
Coding 00002    WSC XXXXX
  • ‒ 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 01-49
  • ‒ Activating cruise control system

=> Current flow diagrams, Electrical fault finding and Fitting locations binder

Servicing diesel direct injection system > < Self-diagnosis