General Information

Output Diagnostic Test Mode (DTM) (Function 03)

NOTE:
- Observe the following for the output Diagnostic Test Mode (DTM)
- The A/C Compressor Regulator Valve -N280- is only activated by the A/C control head -E87- when the engine is not running.
- The request to activate the coolant fans (step 1 and 2) is always transmitted by the A/C control head -E87- to the Engine Control Module (ECM). The engine control module switches the coolant fans on, but only with the engine running.
- The output Diagnostic Test Mode can only be carried out up to an engine speed of 3000 RPM and a vehicle speed less than 5 km/h.
- The Output Diagnostic Test Mode (DTM) can be carried out more than once if necessary.
- Malfunctions on the actuators are stored in the DTC memory.
- The control and the display of the A/C control head -E87- is switched off during the output Diagnostic Test Mode. The segments of the A/C control head -E87- are only activated during the "Segment test" function.
- After selecting the "output Diagnostic Test Mode" function, the positioning motors of the climate control system are being moved into a pre-assigned position. During the output Diagnostic Test Mode, it is not necessary to wait until the positioning motors reach the preassigned position.

Initiating output DTM
- With ignition switched off, connect VAS 5051 Vehicle Diagnostic, Testing and Information System with VAS 5051/1 diagnostic cable to 16-pin data link connector on vehicle. Connecting VAS 5051 Tester
- Switch ignition on/Start engine.

NOTE:
- Switch ignition on (to check the activation of A/C Compressor Regulator Valve -N280-, the engine should not be running)
- Start engine (to activate coolant fans)

- Select "Auto" operating mode on A/C Control Head -E87-.
- Select "Address word" 08 for A/C heater/electronics. Connecting VAS 5051 Tester
- Open dash panel vents.
- Check DTC memory

Indicated on display of VAS 5051:







- Select "Output Diagnostic Test Mode (DTM)" function 03

Indicated on display of VAS 5051:







- Display field -1- shows which actuator is currently being activated (e.g. 1 actuator in test).
- Display field -2 shows the actuators that were already activated one after the other or which one is currently activated. The actuator that is currently activated is displayed in the most lower line.
- By touching the -> button you can call up the next component to be tested. Function and sequence, see table of activated actuators. Output Diagnostic Test Mode (DTM) Procedure

NOTE:
- By clicking the <- button you will return to the selection menu.
- Output DTM can be terminated by pressing the -C- button.
- When output DTM is completed, check DTC memory.
- Check DTC memory when output DTM is aborted and Read Measuring Value Block (display group 002). Measuring Value Blocks (Function 08)