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Testing vacuum system of the automatic heater control - ra83001400164x(0164)

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Model 140 

Operation No. of Job Texts and Work Units, Standard Texts and Flat Rates:

PERMISSIBLE LEAKAGE

Permissible leakage per vacuum circuit (without vacuum supply tank) 30 mbar/min at 400 mbar vacuum
Permissible leakage of vacuum valve block and switch-over valve connector block (Y 13/2) 50 mbar in 10 min at 300 mbar vacuum
Permissible leakage of all other components 20 mbar/min at 300 mbar vacuum

Special tool 

Fig 1: Identifying Special Tools (201 589 13 21 00 00 42 80)
G05440851Courtesy of MERCEDES-BENZ OF NORTH AMERICA.
PARTS FOR THE TEST

3 blind plugs 000 987 29 45
1 vacuum line 129 800 09 15
3 plugs 129 800 95 15

IMPORTANT After completing the work: Erase fault memory in control unit (Diagnosis Manual - Climate Control).

Vacuum diagram for automatic heater control 

Fig 2: Automatic Heater Control Vacuum Diagram
G05440852Courtesy of MERCEDES-BENZ OF NORTH AMERICA.

Connections of switch-over valve connector block 

  1. Testing vacuum valve block, vacuum supply tank and switch-over valve connector block (double, Y13/2) for leaks 
    Fig 3: Identifying Vacuum Supply Tank, Automatic Transmission And Vacuum Valve Block
    G05440853Courtesy of MERCEDES-BENZ OF NORTH AMERICA.

    Vacuum valve block

    Fig 4: Identifying Vacuum Valve Block
    G05440854Courtesy of MERCEDES-BENZ OF NORTH AMERICA.
    Fig 5: Vacuum Valve Block Connection Diagram
    G05440855Courtesy of MERCEDES-BENZ OF NORTH AMERICA.
    CONNECTION DIAGRAM FOR VACUUM VALVE BLOCK

    No. Color From/to
    1 Middle green/yellow Rear air conditioner
    2 Light blue Backrest locking
    3 Violet Headlamp range adjustment switch (input)
    4 Violet/yellow Headlamp range adjustment element (left)
    5 Gray/green Switch-over valve connector block (Y13/2)
    6 White Intake manifold vacuum assistance
    7 Gray Intake manifold vacuum
    8   Connection not assigned
    9 Violet/yellow Headlamp range adjustment switch (output)
    10 Violet/yellow Headlamp range adjustment element (right)
    11 Black/gray Automatic transmission economy program
    12 Black/gray (system)
    13 Red/gray Automatic transmission economy program (supply tank) Air conditioner supply tank
    1. Expose vacuum valve block (36) by removing foot support (front passenger's side).
    2. Pull off gray line (connection 7) and seal off at intake manifold using blind plug.

      Connect tester and test for leaks.

      Fig 6: Identifying Vacuum Valve Block
      G05440856Courtesy of MERCEDES-BENZ OF NORTH AMERICA.
    3. Pull off all lines. Seal connections 5 and 7 with blind plugs. Connect tester to connection 6 with adaptor and evacuate. If there is a loss of vacuum on the pressure gauge, replace vacuum valve block (36).
    Fig 7: Identifying Vacuum Valve Block
    G05440857Courtesy of MERCEDES-BENZ OF NORTH AMERICA.
    NOTE: If no fault was found, test check valves a, b and c in vacuum valve block (36).
    Fig 8: Identifying Vacuum Valve Block Location
    G05440858Courtesy of MERCEDES-BENZ OF NORTH AMERICA.

    Valve a. Seal connection 5 with blind plug, connect tester to connection 13, evacuate with tester and read pressure gauge. If the pressure increases on the pressure gauge, replace vacuum valve block (36).

    Valve b. Seal connections 5, 7 and 13 with blind plugs. Connect tester to connection 7, evacuate with tester and read pressure gauge. If the pressure increases on the pressure gauge, replace vacuum valve block (36).

    Fig 9: Vacuum Valve Block Connection Diagram
    G05440859Courtesy of MERCEDES-BENZ OF NORTH AMERICA.

    Valve c. Connect tester to connection 12, evacuate with tester and read pressure gauge. If the pressure increases on the pressure gauge, replace vacuum valve block (36).

    Connect tester to red-grey vacuum line (connection 13) and evacuate. If the pressure increases on the pressure gauge, check vacuum reservoir for leaks. If required, replace line or vacuum reservoir.

    Connect all vacuum lines except the grey-green one (connection 5) on the vacuum valve block.

    Location of vacuum reservoir (1) in front right of wheelhouse

    Fig 10: Identifying Vacuum Reservoir In Front Right Of Wheelhouse
    G05440860Courtesy of MERCEDES-BENZ OF NORTH AMERICA.

    Preparing for tests b to e 

    1. Connect gray/green vacuum line (connection 5) to tester.
    2. Move temperature selector to white segment.
    NOTE: The tester remains connected to the gray/green vacuum line for the entire duration of the test.

    If leakage is discovered, rectify the fault first (seal off) before proceeding with the next test step.

  2. Checking switch-over valve connector block (Y13/2) for leaks 
    1. Ignition switched off.
    2. Evacuate with tester and read off pressure gauge. If pressure on pressure gauge rises, renew switch-over valve connector block (Y13/2) or gray/green vacuum line.
    Fig 11: Identifying Switch-Over Valve Connector Block
    G05440861Courtesy of MERCEDES-BENZ OF NORTH AMERICA.
  3. Testing vacuum system of automatic heater control for leaks 
  1. Switch on ignition.
  2. Temperature selectors on white area.
Fig 12: Identifying Automatic Heater Control And Button
G05440862Courtesy of MERCEDES-BENZ OF NORTH AMERICA.
  1. Checking vacuum elements for main air flap (43 and 44) and recirculated air flap (49) for leaks 
    Fig 13: Checking Vacuum Elements For Main Air Flap And Recirculated Air Flap For Leaks
    G05440863Courtesy of MERCEDES-BENZ OF NORTH AMERICA.
    1. Air volume switch (S3) at position 0.
    2. Air distributor switch at any position.
      Fig 14: Identifying Air Volume Switch And Air Distributor Switch
      G05440864Courtesy of MERCEDES-BENZ OF NORTH AMERICA.
    3. Evacuate with tester and read pressure gauge. If there is a loss of vacuum on the pressure gauge, test lines to the elements 43, 44 and 49 individually, by exposing the switch-over valve connector block (Repair Instructions Removal and installation of the switchover valve connector block (Y13/2)  ).
    4. Replace defective element(s) or lines.
  2. Checking vacuum elements for center outlet exhaust air flap (41) and center outlet blend flap (45) for leaks
Fig 15: Checking Vacuum Elements For Center Outlet Exhaust Air Flap And Center Outlet Blend Flap
G05440865Courtesy of MERCEDES-BENZ OF NORTH AMERICA.
  1. Air volume switch (S3) in position (see figure).
  2. Air distributor switch at any position.
    Fig 16: Identifying Air Volume Switch And Air Distributor Switch
    G05440866Courtesy of MERCEDES-BENZ OF NORTH AMERICA.
  3. Actuate center outlet W key.
    Fig 17: Identifying Actuate Center Outlet W Key
    G05440867Courtesy of MERCEDES-BENZ OF NORTH AMERICA.
  4. Evacuate with tester and read pressure gauge. If there is a loss of vacuum on the pressure gauge, test lines to the elements 41, and 45 individually, by exposing the switch-over valve connector block (Repair Instructions Removal and installation of the switchover valve connector block (Y13/2)  ).
  5. Renew defective element(s) or lines.
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