Output Diagnostic Test Mode (DTM) Idle speed control test, initiating
- Switch ignition off.
- Remove Engine Control Module (ECM) and connect adapter cable of VAG1598 test box to the connector to ECM.
See WIRING AND COMPONENT CHECK WITH VAG1598/31 TEST BOX . Do not connect ECM to test box.
NOTE:
Terminal assignments of harness connectors to ECM. See SYSTEM WIRING DIAGRAMS.
- Switch ignition on.
- Connect VAG 1551 Scan Tool, insert address word 08 "AC/Heating Electronics" and move forward in program until "Select function XX" is displayed. See VAG 1551 ((VAG 1552) SCAN TOOL (ST), CONNECTING AND SELECTING FUNCTIONS .
- Switch printer on by pressing the PRINT button (indicator lamp in the button comes on).
Indicated on display (function selection):
- Press buttons -0- and -3- to select "Output Diagnostic Test Mode" function 03.
Indicated on display
- Press -Q- button to confirm input.
Indicated on display
- Press => button.
- Once again press buttons -0- and -3-.
Indicated on display
- 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. See READ MEASURING VALUE BLOCK (FUNCTION 08)
(display group 001).
- Connect VAG1527B voltage tester between Ground and input to be tested (to the ECM) at the test box.
- To repair fresh air blower -V2-, see Figure .
- To test with ECM installed, see MULTIPORT FUEL INJECTION (MFI) - 4.2L V8 (AKB) .
- To cause idle speed to be increased or change in pilot control value in ECM, see MULTIPORT FUEL INJECTION (MFI) - 4.2L V8 (AKB) .