VR6 ECU Reset Procedure

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Disconnecting the Engine ECU from it's power supply will loose the "learnt" values in the memory such as the pre-set O2 lambda values for idle, mid throttle and full throttle positions. (NB. If battery is disconnected to reset the ECU or Throttle body or Throttle Position Sensor is changed then the "ECU Reset & Basic Setting" sequence must be done.)

Before starting note the alarm and radio setting codes / set up sequences which be needed for later. Run the engine until the oil temperature is above 85ºC. Disconnect the battery earth for at least 2 minutes. Reconnect the battery earth. Start and drive the car. During the initial 10 minutes since starting the engine, drive the Corrado and carry out several times the following.

1) Drive from 25mph in 4th gear for at least 4 seconds with constant mid throttle (steady gentle acceleration).

2) Drive from 3,500 rpm in 3rd gear for at least 3 seconds at full throttle (hard acceleration).

3) At the end of 1) or 2), allow the Corrado to de-accelerate in the gear with the throttle closed, no brake application.

4) 1), 2) and 3) can be repeated several times.

5) At about 5 minutes, allow the engine to idle for one minute.

After the initial 10 minutes, drive the car normally for a further 20 minutes minimum to allow O2 "learnt" values to be established. Idle will be complete after 10 minutes. The mid and full throttle values will take upto a further 20 minutes to establish. Once the ECU education has been completed, an ECU "Basic Setting" should be performed on group 000 or 001 as detailed below (or you are wasting your time doing this procedure).


Start and warm engine to normal operating temperature. Ensure engine oil temperature is above 85ºC (185ºF). Ensure Air Conditioning and other electrical loads are switched off, including the radiator cooling fan (NB Does not matter if radiator fan operates during "Basic Setting" 2 minute period.)

Connect the VAG 1551 or VAG-COM to diagnostics socket(s) located in centre console, to the front of gear shift lever under the cover surround. Ensure no Diagnostic Trouble Codes (DTC) are stored for the engine ECU. Let the engine run at closed throttle - idle (typically 640 - 690 RPM). Operate VAG1551 or VAG-COM using the following sequences and observe the displays:-

        VAG1551:                                                  VAG-COM:         
        Select address word - 01 (Engine)                         Select 01 - Engine
        Key 04 - Basic Setting, press Q to confirm entry.         Select Basic Settings - 04
        Key 001 (note2) - Display group 001,                      Key 001 (note2) - Display group 001,
        press Q to confirm entry.                                 press "Go!"
        System now in "Basic Setting".                            System now in "Basic Setting".
                  ------------ Increase the engine speed to 2,500 rpm for 3 seconds.  ---------------
                  ------------- Allow to idle for 2 minutes minmum. Check CO level. -----------------
        When radiator fan is NOT running, Press ->, 06, Q         When radiator fan is NOT running, "Done, Go Back".

Motronic M2.9 ECU Group 001

Field 1: Engine RPM - 680rpm (Allowable 650–750rpm).

Field 2: Coolant Temp.- above 85ºC, typically 92ºC/98ºC.

Field 3: Active Lambda - 1.00 +/- 0.2, slowly fluctuating +/-0.02 max, 2 second period, typically.

Field 4: Ignition Timing - 6.00º +/- 1º, fluctuating slightly.

Motronic M2.7 ECU Group 000

Field 1: Coolant Temperature - 185, below 210 corresponds 85ºC to 99ºC.

Field 3: Engine RPM - 65, below 75, corresponds to 650 – 750rpm.

Field 10: Ignition Timing - 85 to 91, corresponds to 4º to 8º BTDC.

(Note2: Motronic ECUs at M2.7 software standard use group 000 for "Basic Setting", ECU part no. 021 906 258B, BF, CC )

(Note2: Motronic ECUs at M2.9 software standard use group 001 for "Basic Setting", ECU part no. 021 906 258AG & CP )

(NB. Basic setting places the ECU into a specific offset condition from which the engine sensors can be measured.)