Golf III L4-1984cc 2.0L SOHC (1993)
Idle Speed/Throttle Actuator - Electronic: Testing and Inspection
With VAG
CHECKING IDLE AIR CONTROL (IAC) VALVE
REQUIREMENTS
^
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.
