Bayer HealthCare Rapidlab 800 - Manual (Page 298)

4Ć14 800 Series Operator's Manual
Perform the Measurement Test as described on page 4-70.
Check the diverter valve to verify that the valve is working by performing the
Valves test as described on page 4-62.
Replace the affected sensor as described in Replacing the Measurement or
Sample Ground/ Temperature Sensors in Section 3.
If the D code reappears, contact your Service Representative.