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This page applies to the 1.2L CR TDI (CFWA) engine which was installed in vehicles such as the Skoda Fabia/Roomster (5J) and VW Polo (6R).

Address 01: Engine (J0000-CFWA)      Labels: 03P-906-021-CFW.clb
   Part No SW: 03P 906 021 T    HW: 03P 906 021 T
   Component: R3 1.2 DCM3.7 H06 2999
   ASAM Dataset: EV_ECM12TDI03103P906021T

General Information about the 1.2L CR TDI (CFWA) engine can be found in the Official Factory Repair Information.

Security Access

  • Security Access codes will appear when connected to the control module with VCDS.


  • Coding information is found using the Long Coding Helper while connected to the vehicle with VCDS.

Basic Settings

  • All available Basic Setting groups will appear in the form of a drop-down menu when connected to the control module with VCDS. The most common Basic Setting groups are:
    • Adaptation of diff. pressure sensor particulate filter
    • Resetting of learned values of difference pressure sensor
    • Resetting of learned values of particle filter
    • Test of auxiliary fuel pump


  • All available Adaptation Channels will appear in the form of a drop-down menu when connected to the control module with VCDS. The most common Adaptation Channels are:
    • Particle filter initialization
    • Service regeneration of particulate filter while driving
    • Injector 1, 2 and 3 correction values

Special Functions

Injector Quantity Adjustment (IMA) and Injector Voltage Adjustment (ISA)

These values represent the behavior of an injection valve (Piezo Injector). Caused by manufacturing tolerances the injectors have a unique behavior and get divided into separate classes. In combination with the automatically determined learning values of the engine control module the pre- and post-injections are being calculated individually for each valve. The behavior of an injection valve is also mileage dependent, so a valve with e.g. 10000 km has a different behavior then one with 70000 km. The control module determines these automatically while driving so the learning values change against the mileage. When altering one of the following values the learning values are being reset because the ECU thinks you are adjusting a new valve.

The IMA-ISA values need to be adapted when:

  • One or more injection valves have been replaced. Make sure not to adjust the valves which have not been changed!
  • The engine control module has been replaced.
  • Do NOT adapt these values when you did not replace one of the above parts, also not for training or demonstration purposes.

The adjustment code can be found on the injector itself. This is usually a 7-digit value but the 1.2L uses Delphi Injectors with a 20-digit code. The 20-digit code on the injector must be converted before the control module will accept the value.

This following chart needs to be used to convert the code(s):

Value on the injector Equals Converted code
0 > 00
1 > 01
2 > 02
3 > 03
4 > 04
5 > 05
6 > 06
7 > 07
8 > 08
9 > 09
A > 0A
B > 0B
C > 0C
D > 0D
E > 0E
F > 0F
G > 10
H > 11
J > 12
K > 13
L > 14
M > 15
N > 16
P > 17
R > 18
S > 19
T > 1A
U > 1B
W > 1C
X > 1D
Y > 1E
Z > 1F

Delphi injector1.jpg
Click on thumbnail image to enlarge.

After converting the code spaces need to be inserted. Using the example fuel injector the new Adaptation channel value would be: 1C 17 07 06 04 08 08 11 0E 06 0F 07 13 07 1A 15 02 0C 1F 00


  • New Fuel Injector IMA-ISA codes available and fuel injector(s) installed.
  • Ignition ON
  • Engine OFF

[01 - Engine]
[Adaptation - 10]
Channel: Injector 1 correction value
Channel: Injector 2 correction value
Channel: Injector 3 correction value

Enter the converted values from each fuel injector as needed.
[Done, Go Back]

  • Switch Ignition OFF, wait 10 seconds and switch Ignition ON again. The values should be saved now, please verify them by double checking the adaptation values.


  • If the IMA-ISA value on the new injector is difficult to read, consider scanning the QR code with a smart phone app.
    • We have had success with BB, Android and iOS platform mobile devices running i-nigma's free app.