System test

Special diagnosis routines can be run with this menu item.

The following conditions must be observed for the system test:

• Vehicle speed < 10^{km /h}
• Engine start detected and 10 seconds elapsed since engine start
• Terminal 15 supply voltage OK
• 5-volt supply voltage OK
• Engine temperature < 110 °C
• Outside temperature > 3 °C
• Engine speed higher than idle speed

The following tests are performed:

• Display of all segments in the control module
• The servo motors are traversed across the entire range once
• The measured positioning travel is subjected to a plausibility test and stored as a fault if necessary
• Two different voltage values are set on the fresh-air blower and tested
• The A/C circuit is tested via the DME
• All fault paths are tested, and any faults are stored

After the system test, the air conditioning system regulator reverts to the state it was in before the test.