Diagnostic Aids

Perform this test when instructed during QUICK TEST or another SYSTEM TEST. Before continuing with this test, ensure that the following areas are in good condition:

• Vacuum hoses and connections.
• Wiring harness connectors.
• Fuel system.
• Aftermarket equipment alterations.
• Air intake filters and tubes.
• Engine mechanical condition.

• Input Test
  
  This test applies only to input devices such as sensors and switches. It also applies to signals such as RPM and speed signals. This is the first testing procedure to use for checking input devices.
• Output Test
  
  This test applies only to output devices such as fuel injectors, idle speed controllers, relays and solenoids. This is the first testing procedure to use for checking output devices.
• Road Test
  
  This test applies to both input and output devices. This test usually is the second type of test to use (perform input or output test first).
• Water Soak Test
  
  This test cannot be performed on all types of devices due to location of device (e.g., under instrument panel) or construction of device (damaged by water or not affected by water at all). This test usually is the last type of test to use in finding intermittent faults.