IAC Regulation, Initiating Output Diagnostic Test Mode (DTM)
Idle Air Control (IAC) Regulation, Initiating Output Diagnostic Test Mode (DTM)
- Switch ignition off.
- Remove Engine Control Module (ECM) and connect adapter cable of VAG 1598/22 test box to ECM connector. Do not connect ECM to test box.
NOTE:
Terminal assignments of harness connectors to ECM:
- Switch ignition on.
- Switch rear window heater off.
- Connect VAG 1551 Scan Tool (ST) Scan Tool Connecting and Initial Checks.
- Press buttons -0- and -8- to insert "AC/Heating Electronics" address word 08 and advance program until "Select function XX" appears on display Scan Tool Connecting and Initial Checks.
- Switch printer on by pressing PRINT button (indicator lamp in the button comes on).
Indicated on display
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
- 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
- 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 Reading.
- To test idling speed regulation function, connect VAG 1527 voltage tester (or equivalent LED type voltage tester) between Ground (GND) and appropriate input (for ECM) on test box.
