Switch Test Mode

The switch inputs used by the SMEC have only two recognized states, HI and LO. For this reason, the SMEC cannot recognize the difference between a selected switch position versus an open circuit, a short circuit, or a defective switch. However, if any one of these subject switches is toggled, the controller does have the capability to respond, indicating that it has recognized a state change. If the change is displayed, it can be assumed that the entire switch circuit to the SMEC is functional.
1. Ensure all switches that send input to SMEC are turned Off.
2. Enter system into Diagnostic Test Mode, then wait until Code 55 has been displayed indicating end of fault code display. On 1988 models, ensure readout box is displaying ``Read.''
3. On all models, turn on the desired switch for input into SMEC.
4. As each switch is opened and closed, display on tester should change. If display does not change as switch is operated, check continuity of wiring between switch and SMEC and repair as needed. If wiring is satisfactory, test each switch individually.