Idle Speed/Throttle Actuator - Electronic: Testing and Inspection
Idle Air Control (IAC) Regulation, Initiating Output Diagnostic Test Mode (DTM)
- Switch off ignition.
- Remove Engine Control Module (ECM) and connect adapter cable of VAG 1598 test box to ECM connector. Do not connect ECM to test box.
NOTE: Terminal assignment of harness connectors to Engine Control Module (ECM).
- Switch on ignition.
- Switch rear window heater off.
- Connect VAG1551 Scan Tool (ST), Press buttons -0- and -8- to insert "AC/Heating Electronics" address word 08 and advance program until "Select function XX" appears on display, Refer to "Scan Tool Testing/Scan Tool Connecting and Initial Checks" under "Heating and Air Conditioning", Testing and Inspection
- Switch printer on via the PRINT button (indicator lamp in button lights up).
Indicated on display (function selection):
Rapid data transfer HELP
Select function XX
- Press buttons -0- and -3- to select "Output Diagnostic Test Mode" function 03.
Indicated on display:
Rapid data transfer Q
03 - Output Diagnostic Test Mode (DTM)
- Press -Q- button to confirm input.
Indicated on display:
Function is unknown or
cannot be carried out at the moment
- Press -> button.
- Once again press buttons -0- and -3-. Indicated on display:
Rapid data transfer Q
03 - Output Diagnostic Test Mode (DTM)
- Press -Q- button to confirm input.
NOTE: If the function "Output Diagnostic Test Mode" is once again entered, the A/C Clutch -N25- is no longer actuated, Read Measuring Value Block (display group 001). Refer to "Scan Tool Testing/Measuring Value Block (Function 08)" under "Heating and Air Conditioning", Testing and Inspection
- To check the "Idle Air Control" (IAC) regulation function: Connect VAG 1527 voltage tester between Ground (GND) and appropriate input (for ECM) on test box.
