MEC 20 MICROPROCESSOR ENGINE/GENERATOR CONTROLLER
PM047 Rev 13 05/03/30
91
Thomson Technology
SYMPTOM (CONT’D)
CORRECTIVE ACTION (CONT’D)
Engine temperature or oil pressure displays
9999
- Check the wiring from the MEC 20 terminal #37 &
#38 to the engine mounted sender are correct (i.e.
wiring is not open or shorted).
- Verify the engine mounted senders have correct
resistance reading for corresponding input
temperature or pressure (refer to the Analog
Temperature and Pressure Calibration table for
values).
- Verify calibration.
Engine alarms on high engine temperature or
low oil pressure when engine is operating
within normal limits
- Check the wiring from the MEC 20 terminals #37 &
#38 to the engine mounted senders is correct (i.e.
wiring is not open or shorted).
- Verify the engine mounted senders have correct
resistance reading for corresponding input
temperature or pressure (refer to the Analog
Temperature and Pressure Calibration table for
values).
Key presses on the lexan faceplate do not
operate
- Verify the interconnecting ribbon cable between the
lexan faceplate and main printed circuit board is
correctly connected.