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" which follows. If problems do exist, a service code will be displayed (as pulses on a voltmeter). Locate the appropriate 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:

• Dial Voltmeter (0-20v scale)
• Digital Voltmeter (DVOM - Min. impedance 10 megohms)
• Vacuum Gauge (0-30 in. Hg)
• Vacuum pump
• Tachometer
• Jumper Wire