Operating Conditions of Engine, Checking

Operating Conditions of Engine, Checking

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

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

Test condition

- 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 Engine Control Module (ECM) using address word 01 (connecting scan tool and selecting ECM). [1][2][3]Connecting VAG 1551 Scan Tool

Indicated on display

Rapid data transfer HELP
Select function XX

- Press 0 and 8 of function "Read Measuring Value Block", and then press Q to exit from input mode.

Indicated on display

Read Measuring Value Block
Input display group number XXX

- Press 0, 0 and 5 for the function "display group number 5", and then press Q to exit from input mode.

Indicated on display (1 - 4 = display fields)

Read Measuring Value Block 5 ->
1 2 3 4

- Check if control module recognizes operating conditions (display field 4).
- Idle: (as long as the engine is idling, "idle" should be indicated)

Display: Idle

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

Display: Deceleration

NOTE: Below 1400 RPM idle will be recognized again.

- Partial throttle:
- Hold gas pedal steady (as long as gas pedal is held steady, "partial throttle" should be indicated).

Display: Partial throttle

- Enrichment:
- Open throttle all the way (as far as throttle valve goes).

Acceleration enrichment should be briefly indicated

Display: Enrich

Observe safety precautions which 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 expected values are not obtained:
- Check DTC memory, repair any malfunctions and then erase DTC memory.
- Test throttle valve control module. Testing and Inspection