Engine Operating Mode Check

Engine operating mode, checking

NOTE: Checks whether the Engine Control Module recognises the engine operating modes: Closed Throttle, Overrun, Part throttle, Enrichment and Wide Open Throttle throttle.

Special tools, testers, measuring instruments and auxiliary items required
- VAG 1551/1552 Scan Tool with VAG 1551/3B adaptor cable

Check conditions
- Coolant temperature must be 85 °C minimum See Display group 04, Display zone 3
- Throttle cable adjustment OK

Test sequence
- Connect VAG 1551/1552 Scan Tool, [1][2][3]Reading and Clearing Diagnostic Trouble Codes
- Start engine and let idle
- Press 0 and 1 buttons to select "Address word" 01 "Engine electronics"

Display will appear as shown


Rapid data transfer HELP
Select function XX


- Press 0 and 8 buttons to select Function 08: "Read measuring value block"
- Press Q button to enter input Display will appear as shown


Read measuring value block HELP
Input Display group number XXX

- Press 0, 0 and 5 buttons to select "Display group 5"
- Press Q button to enter input

Display will appear as shown (1 to 4 = Display zones)


Read measuring value block 5 ->
1 2 3 4


- Check whether the Engine Control Module recognises the operating mode (Display zone 4):

Closed Throttle Position (Idling)
As long as engine is idling; idling must be displayed

Display: Idling

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

As long as engine speed is above 1400 rpm; overrun must be displayed

Display: Overrun

NOTE: Below 1400 rpm idle speed will be recognised.

Part throttle:
- Rev up evenly

As long as engine is being revved up evenly part throttle must be displayed

Display: Part throttle

Enrichment:

- Quickly increase engine speed.

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 (Wide Open Throttle)

NOTE:
- A test drive may be required to show "Full throttle" in Display.
- A 2nd person is required when performing a test drive.

WARNING!
Secure Scan Tool to rear seat. Operate tool and take measurements from this position.

- Press -> button.
- Press 0 and 6 buttons to select Function 06: "End data transfer"
- Press Q button to enter input If specifications not obtained:
- Check DTC memory, if necessary, repair any malfunctions and then erase DTC memory Reading Diagnostic Trouble Codes

- Check accelerator mechanism for ease of operation
- Check Throttle Position sensor, Testing and Inspection