Engine Operating Mode, Checking

NOTES: Checks whether Engine Control Module (ECM) recognizes the engine operating modes idling, overrun, part throttle, enrichment, full throttle.

Special tools, test equipment and auxiliary items
- Scan tool V.A.G 1551 or vehicle system tester V.A.G 1552 with cable V.A.G 1551/3B

Test conditions
- Coolant temperature must be at least 85 °C See display group 04, display zone 3.

Test sequence
- Connect scan tool V.A.G 1551 (V.A.G 1552). Start engine and select "Address word" 01 of engine control module. When doing this the engine must be running at idle speed. Connecting scan tool and selecting Engine Control Module (ECM).

Indicated on display

Rapid data transfer HELP
Select function XX

- Press keys 0 and 8 for the function "Read measuring value block" and confirm entry with Q key.

Indicated on display

Read measuring value block
Input display group number XXX

- Press keys 0, 0 and 5 for "Display group number 5" and confirm entry with Q key.

Indicated on display (1-4 = Display zones)

Read measuring value block 5 ->
1 2 3 4

- Check whether the control module recognizes the operating mode (display zone 4):

Idling:
As long as the engine is running at idle speed "idling" must be displayed
- Display: Idling

Overrun mode:
- Increase engine speed to above 3000 RPM.
- Close throttle abruptly.

As long as the engine speed is above 1400 RPM "overrun" must be displayed
- Display: Overrun

NOTES: A test drive may have to be performed to show "Overrun" in display.

Observe the valid safety precautions when carrying out a road test.

Part throttle:
- Rev up evenly.

As long as the engine is being revved up evenly, "part throttle" must be displayed
- Display: Part throttle

Enrichment:
- Floor accelerator pedal (onto throttle valve stop).

Acceleration "enrichment" must be displayed briefly
- Display: Enrichment

Full throttle:
- Floor accelerator pedal (onto throttle valve stop).

"Full throttle" must be displayed briefly
- Display: Full throttle


NOTES: A test drive may have to be performed to show "Full throttle " in display.


Observe the valid safety precautions when carrying out a road test.
- Press key.
- Press keys 0 and 6 for the function "End output" and confirm entry with the Q key.

If the specifications are not attained:
- Check DTC memory, if necessary, repair any malfunctions and then erase DTC memory. Testing and Inspection
- Check accelerator mechanism for ease of operation.
- Check throttle valve potentiometer See Checking throttle valve control module. Testing and Inspection
- Read-out the readiness code. Testing and Inspection
If the DTC memory has been erased or the engine control module was disconnected from permanent positive, the readiness code must be generated again. Testing and Inspection