Engine Operating Mode Check

NOTE: This test determines whether the Engine Control Module (ECM) recognizes the engine operating conditions idle, deceleration mode, partial throttle and enrichment of the engine.


Special tools and equipment
- V.A.G 1551 scan tool (or VAG 1552 mobile scan tool) with VAG 1551/3B cable

Test requirement
- Coolant temperature must be at least 80 °C, See display group 04, display field 3

Test sequence
- Connect V.A.G 1551 scan tool (VAG 1552). Start engine and select the Engine Control Module (ECM) using address word 01. (connecting scan tool and selecting ECM).

Indicated on display:


Rapid data transfer HELP
Select function XX


- Press 0 and 8 for the function "Read measuring value block", and then press Q to exit from input mode.

Indicated on display:


Read measuring value block
Enter display group number XXX


- Press buttons -0-, -0- and -5- to select "Display group number 5". Press -Q- button to confirm input.

Indicated on display: (1 to 4 = display fields)


Read measuring value block 5 ->
1 2 3 4


- Check whether control module recognizes the operating conditions (display field 4).

- Idle:
As long as the engine is idling "idle" should be indicated. Indication: Idle

- Overrun:


NOTE: Deceleration is sometimes only indicated while driving.


- Increase engine speed to above 3000 RPM.
- Then abruptly close throttle valve.
As long as engine speed is over 1400 RPM, "overrun" should be indicated. Indication: Deceleration


NOTE: Below 1400 RPM idle will be recognized again.


- Partial throttle:
- Hold gas pedal steady.
As long as gas pedal is held stead, "partial throttle" should be indicated. Indication: Partial throttle
- Enrichment:
- Briefly depress accelerator pedal completely.
Acceleration enrichment should be briefly indicated. Indication: Enrich.

Observe the safety precautions that apply to road tests.

- Press -> button.
- Press buttons -0- and -6- to select "End data transfer" function 06. Press -Q- button to confirm input.

If specified values are not obtained:
- Check DTC memory, repair any malfunctions and then erase DTC memory, Checking and erasing DTC memory.
- Check the throttle valve control module. Testing and Inspection