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Diagnostic Manual, Climate Control, Volume 1

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LOCATION:    3.8 Air Conditioning (A/C)    >   32 Pneumatic Test Program - Test


Pneumatic Test Program - Test

Preparation for Test

1. Review 11 , 12 , 14 , 15 , 20 , 21 , 22 , 31 , 32 , 41
2. Disconnect all vacuum lines at vacuum distributor block (36).

3. Check gray vacuum line to intake manifold for leaks.


Permissible leakage of the elements with vacuum lines at 400 mbar vacuum per minute is 30 mbar.

Test equipment; See MBUSA Standard Service Equipment Program

Description Brand, model, etc.
Connector 129 805 04 44

A. Vacuum Distributor Block, Vacuum Reservoir, Switchover Valve Block (Y11/3) Test

Test scope Test connection Test condition Nominal value Possible cause/Remedy
1.0 Entire vacuum distributor block Connection "P" on vacuum tester. Evacuate system with
300 mbar vacuum
30 mbar
pressure
increase in
1 minute
Vacuum distributor block,
1.1
1.1 Vacuum distributor block,
check valve "a"
Connection "1" on vacuum tester. Evacuate system with
300 mbar vacuum
30 mbar
pressure
increase in
1 minute
Vacuum distributor block,
1.2
1.2 Vacuum distributor block,
check valve "b"
Connection "4" on vacuum tester. Evacuate system with
300 mbar vacuum
30 mbar
pressure
increase in
1 minute
Vacuum distributor block.
2.0 Vacuum reservoir with
vacuum line
Red/gray vacuum line (connection 3) on vacuum tester Evacuate system with
300 mbar vacuum
30 mbar
pressure
increase in
1 minute
Vacuum lines,
Vacuum reservoir.
3.0 Switchover valve
block (Y11)
Ignition: OFF
medium green line (connection 5) on vacuum tester
Evacuate system with
300 mbar vacuum
30 mbar
pressure
increase in
1 minute
Vacuum lines,
Y11

 
    P83.40-2049-01

B. Vacuum system Test

Test scope Test connection Test condition Nominal value Possible cause/Remedy
1.0 Defroster air outlet vacuum actuator, long stroke Medium green line on vacuum tester Ignition: ON
Press
Evacuate system with
300 mbar vacuum
30 mbar
pressure
increase in
1 minute
Vacuum line,
Vacuum actuator 38
1.1 Defroster air outlet vacuum actuator, long and short stroke Medium green line on vacuum tester Ignition: ON
Press
Evacuate system with
300 mbar vacuum
30 mbar
pressure
increase in
1 minute
Vacuum line,
Vacuum actuator 38
2.0 Diverter valve flap - center air outlet Medium green line on vacuum tester Ignition: ON
Press
Temperature selector " "
Evacuate system with
300 mbar vacuum
30 mbar
pressure
increase in
1 minute
Vacuum line,
Vacuum actuator 41
3.0 Blend air flap - center air outlet Medium green line on vacuum tester Ignition: ON
Press
Evacuate with
300 mbar vacuum
30 mbar
pressure
increase in
1 minute
Vacuum line,
Vacuum actuator 45 and 46
4.0 Footwell flap, long stroke Medium green line on vacuum tester Ignition: ON
Press
Evacuate system with
300 mbar vacuum
30 mbar
pressure
increase in
1 minute
Vacuum line,
Vacuum actuator 39
4.1 Footwell flap vacuum actuator, long and short stroke. Medium green line on vacuum tester Ignition: ON
Press
Evacuate system with
300 mbar vacuum
30 mbar
pressure
increase in
1 minute
Vacuum line,
Vacuum actuator 39
5.0 Fresh/recirculating air flap vacuum actuator. Medium green line on vacuum tester Ignition: ON
Illuminates
Evacuate system with
300 mbar vacuum
30 mbar
pressure
increase in
1 minute
Vacuum line,
Vacuum actuator 42
6.0 Left air outlet vacuum actuator. Medium green line on vacuum tester Ignition: ON
Left side air outlet adjuster closed.
Evacuate system with
300 mbar vacuum
30 mbar
pressure
increase in
1 minute
Vacuum line,
Vacuum actuator 46
7.0 Center air outlet vacuum actuator. Medium green line on vacuum tester Ignition: ON
Center air outlet adjuster closed.
Evacuate system with
300 mbar vacuum
30 mbar
pressure
increase in
1 minute
Vacuum line,
Vacuum actuator 47.
8.0 Right side air outlet vacuum actuator. Medium green line on vacuum tester Ignition: ON
Right side air outlet adjuster closed.
Evacuate system with
300 mbar vacuum
30 mbar
pressure
increase in
1 minute
Vacuum line,
Vacuum actuator 48
9.0 Center air outlet,
"Cold" pushbutton
Medium green line on vacuum tester Ignition: ON
"Cold" function indicator lamp in "cold" pushbutton (blue) illuminates.
Evacuate system with
300 mbar vacuum
30 mbar
pressure
increase in
1 minute
Vacuum line,
Vacuum actuator 41
10.0 Center air outlet,
"Warm" pushbutton
Medium green line on vacuum tester Ignition: ON
"Warm" function indicator lamp in "warm" pushbutton (red) illuminates.
Evacuate system with
300 mbar vacuum
30 mbar
pressure
increase in
1 minute
Vacuum line,
Vacuum actuator 45