Using the Push-button and LED

Model 124, California Version:

1. Turn ignition "ON".
2. Press push button on data-link connector for 2 - 4 seconds.
3. Read and record fault code(s) (DTC).
- The LED will commence with (blink) impulse readout.
- The fault code will be indicated by the number of LED impulses. Take note of the number of impulses.
- After the fault code has been displayed, the LED will remain lit.
4. Press push button again for 2 - 4 seconds.
5. Read and record the next fault code.
6. Repeat steps 2 and 5 until the first fault code reappears.


NOTE: It is only possible to read codes from the Diagnostic Module (DM) using this procedure. All other modules/systems require the use of either a Mercedes Hand-Held Tester or an impulse counter scan tool.

NOTE: DTC's which have been stored due to testing or disconnecting of lines must be erased from the DTC memory at the end of testing.