Matching engine control unit to throttle valve control part — VW

When matching with ignition switched on but engine not running the engine control unit learns the throttle valve control part limit positions and a comparison curve between throttle valve potentiometer and throttle valve positioner.

Matching sequence must be performed if:

The voltage supply is interrupted
The throttle valve control unit is removed and installed
The throttle valve control unit is renewed
The engine control unit is replaced
If when installing another engine another throttle valve control unit is installed

Special tools, workshop equipment, 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

Test conditions

No faults must be stored in fault memory => Page
01-13
, interrogating and erasing fault memory.
The battery voltage must be at least 11.5 V.
All electrical consumers, e.g. lights and rear window heating must be switched off.
The throttle valve must be at idling speed position.
The cruise control system must be functioning correctly if installed.
Throttle cable adjustment must be OK, checking:

=> Repair group 20; Throttle controls; Adjusting throttle cable
4AV injection and ignition system
Throttle controls
Adjusting throttle cable

Work sequence

Connect the fault reader V.A.G 1551 (V.A.G 1552). Then switch ignition on and select engine control unit with the "Address word" 01.
(Connecting fault reader and selecting engine control unit => Page
01-5
.)

Rapid data transfer
HELP
Select function XX
Indicated on display:

Press keys 0 and 4 for the function "Introduction of basic setting" and confirm entry with Q key.

Basic setting
Input display group number XXX
Indicated on display:

Press keys 0, 9 and 8 for "Display group number 98" and confirm entry with Q key.

System in basic setting
98
⇒
x.xxx V
x.xxx V
Idling ADP. runs
Indicated on display:

After pressing the Q-key the throttle valve positioner is driven to Min., Max. and five intermediate positions and the relevant throttle valve angle stored in non-volatile memory. This procedure takes approx. 10 seconds. The throttle valve then remains in the start position for a brief period then closes.

System in basic setting
98
⇒
x.xxx V
x.xxx V
Idling ADP. OK.
Indicated on display:

Matching has been performed successfully.

To store the values:

Switch off ignition.

Note:

If the basic setting of the control unit is interrupted, the cause could be one of the following:

Throttle valve cannot reach the mechanical stop because of contamination e.g. oil deposits or an incorrectly adjusted throttle cable.
Battery voltage too low.
Throttle valve control unit or wiring is defective. Checking => Page
24-31
.

After an interruption the possible faults are stored in fault memory. When next switching on ignition the basic setting is automatically performed again.

End the engine basic setting by pressing the⇒ key.
Check specifications of throttle valve control part in display group 5 (display zone 4), => Page
01-65
, evaluating measured value blocks. If the specifications are not obtained, repeat matching.
Press keys 0 and 6 for the function "End output" and confirm entry with the Q key.