With Manufacturer's Scan Tool

Idling Check

NOTE:
- Idling speed, ignition timing and CO content not adjustable.
- The idling speed is regulated to specification by the throttle valve positioner in conjunction with the DIS function.
- CO content regulated by oxygen sensor control. Malfunctions in oxygen sensor control are detected in On Board Diagnostic (OBD) and stored in DTC memory.

Special tools and equipment
- V.A.G1551 scan tool or V.A.G1552 mobile scan tool with V.A.G1551/3B cable

Check conditions
- Exhaust system between cylinder head and catalyst free of leaks
- Coolant temperature must be at least 80 degrees C, see display group 04, display zone 3.
- All electrical consumers, e.g. lights and rear window defogger must be switched off
- If the vehicle is equipped with an air conditioner, this must be switched off.
- On vehicles with automatic transmission selector lever in "P" or "N" position

Test sequence
- Connect V.A.G1551 scan tool (V.A.G1552). Start engine and select "Address word" 01 of engine control module. Engine must be running at idling speed. (Connecting scan tool and selecting engine control module. [1][2][3]Connecting VAG 1551 Scan Tool)
- Check DTC Memory, if necessary, repair malfunction and then erase DTC Memory.
- Then:
- Leave V.A.G1551 scan tool connected.
- Continue running engine at idling speed.

Indicated on display:

Rapid data transfer HELP
Select function XX

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

Indicated on display:

Basic setting HELP
Input display group number XXX

- Press keys 0, 0 and 1 for "Display group number 1" and confirm entry with Q key.

Indicated on display: (1 to 4 = Display zones)

System in basic setting 1
1 2 3 4

NOTE: In the "System in basic setting" function the evaporative emission (EVAP) canister purge regulator valve -N80- is closed and the air conditioner compressor switched off.

- Check adjustment conditions for basic setting in display zone 4:
Specification: 1x111111
Significance of the numbers.

- Briefly increase engine speed (rev- up) and then allow engine to run at idling speed for 2 minutes.

Checking idling speed
- Check display group 56 as follows:
- Press C key.
- Press keys 0, 5 and 6 for "Display group number 56" and confirm entry with Q key.

Indicated on display:(1 to 4 = Display zones)

System in basic setting 56
1 2 3 4

- Check operating mode in display zone 4
Specification: 0x000

- Check specified idling speed in display zone 2.
Specification:
- Manual transmission 760 RPM
- Automatic transmission 700 RPM
- Check idling speed in display zone 1.
Specification:
- Manual transmission 700 to 820 RPM
- Automatic transmission 640 to 760 RPM

NOTE: During idling check the EVAP canister purge regulator valve and the air conditioner are switched off and the oxygen sensor control learning procedure is initiated.

- Press -> key.
- Press keys 0 and 6 for "End data transfer" function and confirm input with Q key.

If the idling speed is not obtained:
- Adapt engine control module to throttle valve control module.
- Test drive vehicle.

Observe the valid safety precautions when performing a road test.

- Again check control module DTC memory.
- Repeat idling check.

If the specifications are not obtained again:
- Check throttle valve control module.
- Check operating condition of engine.
- Check intake air system for unmetered air. Testing and Inspection