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Brake light switch signal: testing > < Speed signal: testing

Leon Mk2

Signals from/to the air conditioner: testing
   
Signals from/to the air conditioner: testing
Special tools and workshop equipment required
t  Fault reader -V.A.G 1551- or vehicle systems checker -V.A.G 1552- with lead -V.A.G 1551/3B-
t  Test box -V.A.G 1598/22-
t  Hand-held multimeter -V.A.G 1526 A- or multimeter -V.A.G  1715-
t  Auxiliary measurement set -V.A.G 1594 C-
t  Wiring diagram

Test conditions
l  All electrical consumers, for example lights and heated rear window, must be off.
l  Air conditioning functioning, OK.
l  The air conditioner must be off.
l  The vehicle must be at ambient temperature (over + 15 °C).
l  There must not be any faults stored in the memory → Chapter, Fault memory: consulting and clearing.
Test process
–  Connect the -V.A.G 1551- (-V.A.G 1552-). Start the engine and enter “address code” 01 to select the engine control unit. (Fault reader: Connecting and selecting the engine control unit⇒ page .) → Chapter.)
   
The display reads:
–  Press 0 and 8 for the function “Read measurement value block” and press Q to confirm the entry.
  
Rapid data transmission             HELP
Select function XX
The display reads:
–  Press 0, 5 and 0 for “Display group number 50” and press Q to confirm the entry.
  
Read measurement value block        HELP
Enter display group number XXX
The display reads: (1 … 4 = display fields)
–  Check the message in display field 3. It should read:
   A/C-Low
–  Check the message in display field 4. It should read:
   Compr. OFF
–  Switch on the air conditioner.
–  Set to the lowest temperature and maximum blower speed.
The message in display field 3 should change to
   A/C-High
The message in display field 4 should change to
   Compr. ON
–  Floor the accelerator pedal and release it (throttle burst).
The message in display field 4 should change for a few seconds, from
   Compr. ON
to
   Compr. OFF
(deactivation of the compressor in vehicle acceleration phase).
–  Press →.
–  Press 0 and 6 for the function “End data transmission” and press Q to confirm the entry.
–  Switch off the ignition.
If the message does not change:
  
Read measurement value block    50    ->
         1         2         3         4
–  Connect test box -V.A.G 1598/22- to the control unit wiring harness.
–  Test for open circuits in the wiring between test box female contact 17 + 42 and the air conditioner following the wiring diagram.
   Wiring resistance: 1.5 Ω max.
If there is no fault in the wiring:
–  Consult the fault memory; eliminate any faults and clear the memory → Chapter, Fault memory: consulting and clearing.
–  Test the functioning of the air conditioner controls.
  N24-0709

Brake light switch signal: testing > < Speed signal: testing