Retrieving Diagnostic Trouble Codes

Connect impulse counter scan tool and on-off ratio tester according to connection diagram. See Fig 1 and Fig 2 .

1. Turn ignition ON.
2. Press start button for 2-4 seconds.
3. Read and record DTC readout.
4. Press start button again for 2-4 seconds.
5. Read and record DTC readout.
6. Repeat steps  4 and  5 until the first DTC reappears.

Fig 1: Identifying Special Tools

Courtesy of MERCEDES-BENZ OF NORTH AMERICA.

Fig 2: Connection Diagrams

Courtesy of MERCEDES-BENZ OF NORTH AMERICA.