W210 HVAC Diagnosis

Discussion in 'Other Cars' started by SilverStar, Feb 17, 2015.

  1. SilverStar

    SilverStar New Member

    Jun 22, 2013
    HVAC Diagnosis Procedure:

    Ignition ON
    Temperature selector left "HI", right "LO". Within 20 seconds, press RESET and EC simultaneously for more than 5 seconds The led in the RECIRCULATE button flashes and the display shows "di R" Press AUTO repeatedly until all DTC's (refer to DTC table) are displayed.

    Record each DTC as it is displayed. Each malfunction (short circuit, open circuit, etc.) has a specific DTC assigned to it. The letter "E" (Error) is displayed in the left side of the display and the DTC is displayed in the right side of the display.

    By pressing the right AUTO button, the next DTC stored in memory will be displayed. To erase: Only possible after all DTC's are read out. Simultaneously press both AUTO > 2 secs. "d" will be displayed in the left side of the display window and "FF" on the right side.

    To cancel erase: By pressing AUTO the current faults will appear again. Set temperature selector to normal setting. Turn ignition OFF to end test.

    DCT table:
    B1226 - In-car temperature sensor (B10/4)
    B1227 - Outside temperature indicator temperature sensor (B14)
    B1228 - Heater core temperature (B10/1)
    B1229 - Heater core temperature (B10/1)
    B1230 - Evaporator temperature sensor (B10/6)
    B1231 - ECT sensor (B11/4)
    B1232 - Refrigerant pressure sensor (B12)
    B1233 - Refrigerant temperature sensor (B12/1)
    B1234 - Sun sensor (B32)
    B1235 - Emissions sensor (B31)
    B1241 - Refrigerant fill
    B1416 - Coolant circulation pump (M13)
    B1417 - Duovalve (Y21y1), left
    B1418 - Duovalve (Y21y2), right
    B1419 - Electromagnetic clutch (A9k1) B1420 - Idle speed increase
    B1421 - Pulse module (N65)
    B1422 - Series interface (K1) connection to instrument cluster (A1)
    B1423 - Switchover valve block (Y11) B1424 - Activated charcoal filter actuator (A32m2) open
    B1425 - Activated charcoal filter actuator (A32m2) closed
    B1432 - Non-USA DTC
    B1459 - Series interface (K2) connection to instrument cluster (A1)
    B1462 - Wide open throttle (WOT) position signal: Diesel engines
    IanB and RyanV like this.