Toyota Cressida and Van 1983-1990

Idle-Up and High Temperature A/C Line Pressure Up System

Print

TESTING





Click image to see an enlarged view

Fig. Fig. 1 Idle-up system wiring schematic-Van



Click image to see an enlarged view

Fig. Fig. 2 Place the idle-up temperature switch into a canister of water and test the continuity with a ohmmeter



Click image to see an enlarged view

Fig. Fig. 3 Check the VSV system for an open circuit as shown-Van



Click image to see an enlarged view

Fig. Fig. 4 Using an ohmmeter, make sure there is no continuity between each terminal and the body of the VSV



Click image to see an enlarged view

Fig. Fig. 5 Check the VSV operation by applying battery voltage and inserting air to the valve



Click image to see an enlarged view

Fig. Fig. 6 Electronic component locations-1983-87 Van



Click image to see an enlarged view

Fig. Fig. 7 Electronic component locations-1988-89 Van

This procedure applies to Van models only.

  1. Drain the engine coolant into a suitable container. Separate the idle-up temperature switch connectors.
  2.  


CAUTION
When draining engine coolant, keep in mind that cats and dogs are attracted to ethylene glycol antifreeze and could drink any that is left in an uncovered container or in puddles on the ground. This will prove fatal in sufficient quantity. Always drain coolant into a sealable container. Coolant should be reused unless it is contaminated or is several years old.

  1. Unscrew the switch from the engine.
  2.  
  3. Place the switch in a suitable container filled with water, then gradually heat the water.
  4.  
  5. Using an ohmmeter, check that there is no continuity between the terminal and body when the temperature is below 217°F (103°C).
  6.  
  7. Check that there is continuity between the terminal and the body when the temperature is above 230°F (110°C).
  8.  
  9. If the operation is not as specified, replace the switch.
  10.  
  11. Inspect the vacuum switching valve of the system for an open circuit as follows:
  12.  
    1. Using an ohmmeter, check that there is continuity between the terminals.
    2.  
    3. The resistance cold should be 37-44 omega .
    4.  
    5. If there is no continuity, replace the vacuum switching valve.
    6.  

  13. Inspect the vacuum switching valve of the system for a ground as follows:
  14.  
    1. Using an ohmmeter, check that there is no continuity between each terminal and the body.
    2.  
    3. If there is continuity, replace the vacuum switching valve.
    4.  

  15. Inspect the vacuum switching valve operation:
  16.  

Check the Vacuum Switching Valve (VSV) operation by applying battery voltage to the terminals and blowing through the valve. The VSV should be open (air passes through) when energized and closed (no air passage) when power is removed.

  1. Inspect the idle speed control vacuum switching valve of the system for an open circuit as follows:
  2.  
    1. Using an ohmmeter, check that there is continuity between the terminals. The resistance cold should be 37-44 omega .
    2.  
    3. If there is no continuity, replace the vacuum switching valve.
    4.  

  3. Inspect the idle speed control vacuum switching valve of the system for a ground as follows:
  4.  
    1. Using an ohmmeter, check that there is no continuity between each terminal and the body.
    2.  
    3. If there is continuity, replace the vacuum switching valve.
    4.  

  5. Inspect the idle speed control vacuum switching valve operation:
  6.  

Check the Vacuum Switching Valve (VSV) operation by applying battery voltage to the terminals and blowing through the valve. The VSV should be open (air passes through) when energized and closed (no air passage) when power is removed.

 
label.common.footer.alt.autozoneLogo