Diagnosis & Testing: Notes

The MCU system is capable of diagnosing some problems which may occur. To determine which components should be checked, perform the FUNCTIONAL TEST.

If problems do exist, a service code will be displayed (as pulses on a voltmeter). Locate the appropriate code test chart and follow the repair procedure as instructed. DO NOT  use the test charts unless referred to them by the FUNCTIONAL TEST, or you may replace some components unnecessarily. Testing procedures require the following equipment:

• Analog Volt/Ohmmeter (0-20 volt scale)
• Digital Volt/Ohmmeter (DVOM - Min. impedance 10 megohms)
• Vacuum Gauge (0-30 in. Hg)
• Vacuum Pump
• Tachometer
• Jumper Wire
• Timing Light
• Test Light (12-volt)
• Torque Wrench with deep 1 1/8" socket
• Steel Rod (socket extension) and 4 oz. Hammer
• Watch with second hand