With VAG
CHECKING IDLE AIR CONTROL (IAC) VALVEREQUIREMENTS
^ No Diagnostic Trouble Code (DTC) stored in DTC Memory.
^ VAG 1551 Scan Tool (ST) connected with "Read Measuring Value Block" function (08) selected (display group number 1).
PROCEDURE
^ Indicated on display (1 - 4 = display fields)
Read measuring value block 1 -->
1 2 3 4
- Continue testing only when:
^ Coolant temperature is over 80°C (176°F) - display field 2.
^ Engine has run 2 minutes more at idle.
- Press -C- button.
- Press buttons -0- and -5- to select display group number 5.
- Press -Q- button to confirm input.
^ Indicated on display (1 - 4 = display fields)
Read measuring value block 5 -->
1 2 3 4
- Read duty cycle in display field 3 and write down.
- Disconnect connector -1- from Engine Coolant Temperature Sensor (ECT) -2-.
- Duty cycle must increase and fall back to previous value.
NOTE: Testing can only be repeated if DTC Memory is erased first.
- Connect Engine Coolant Temperature Sensor.
- Press --> button.
- Press buttons -0- and -5- for "Erase DTC Memory" function.
- Press -Q- to confirm input.
- Press --> button.
- Press buttons -0- and -6- to select the "End Output" function.
- Press -Q- to confirm input.