Test Prerequisites

Output Diagnosis Test Mode (DTM), Performing

The Output Diagnosis Test Mode (DTM) activates the following components in the stated sequence:

Special tools, workshop equipment, testers, measuring instruments and auxiliary items required







- VAG 1551 scan tool (or vehicle system tester VAG 1552) with VAG 1551/3 Adapter cable adapter

NOTE: All functions which could previously be performed with VAG 1551/1552 can also be performed with the vehicle diagnostic, testing and information system VAS 5051.

- VAG 1598/31 Test box
- VAG 1594 Adapter set
- VAG 1526 Hand multimeter or VAG 1715 multimeter
- VAG 1527 LED test light
- Electrical Wiring Diagrams

Test prerequisites







- The fuses must be OK.







- The main fuses must be OK.
- The battery voltage must be at least 11.5 V.
- Ground (GND) connection between engine and body must be OK.
- All electrical devices, e.g. lights and rear window heating must be switched off.
- If the vehicle is equipped with air conditioning, it must be turned off.
- Selector lever must be in position "P" or "N" on vehicles with an automatic transmission.
- Fuel Pump (FP) relay -J17- must be OK, checking:
- Motronic Engine Control Module (ECM) Power Supply Relay -J271- must be OK., checking:
- Ignition switched on, engine not running.

NOTE:
- The Output Diagnosis Test Mode (DTM) can only be carried out if the engine is not running and ignition is switched on.
- The Output Diagnosis Test Mode (DTM) will be aborted if the engine is started or a rotational impulse is recognized.
- During the Output Diagnosis Test Mode (DTM) the individual control elements will be activated for approx. 60 seconds or until advancing to the next final control by pressing the button.
- The Output Diagnosis Test Mode (DTM) can be aborted by pressing the -C- button. Therefore there is no need to continue to the end by pressing the button. This is especially important because the fuel injectors can be actuated with the button according to the firing order and fuel injector.
- The electric fuel pump will run during the complete Output Diagnosis Test Mode (DTM).
- The Output Diagnostic Test elements are checked by hearing or by feeling.
- The Output Diagnosis Test Mode (DTM) will be aborted after 10 minutes.
- Run engine briefly first if there is a requirement to repeat Output Diagnosis Test Mode (DTM).