Electronics International MVP-50T, Installation Instructions Manual

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B. Symptom: The sensor counts decrease as you add fuel.
1. Problem:
The probe selected in the “1. EDC Input to Function Mapping” screen is the wrong probe.
a) Action: Check the Probe selected in the “1. EDC Input to Function Mapping” screen. The
“RFLM-4 H=F” probe should be used on Resistive Floats where high resistance = full tank readings
and the “RFLM-4 L=F” probe should be used on Resistive Floats where low resistance = full tank
readings.
7.9 Capacitive Fuel Level Problem:
Fuel can be measured in a fuel tank using a Capacitive Fuel Probe. The Electronics International P-300 Capacitive
Fuel Probe connects to an IMC (Interface Module), located near the probe, and to the EDC through three wires. Power
(+5 volts) is supplied on the Red wire, ground is supplied on the Black wire and the fuel level signal (a 0 to +5 volt
square wave) is on the White wire.
As the fuel level in the tank increases, the capacitance of the probe increases. The IMC Module converts the
capacitance to a frequency. The higher the fuel level, the lower the frequency of the square wave on the White wire.
The EDC monitors the signal and produces a digital value (called sensor counts) based on the signal frequency. The
sensor counts can be viewed in the “Fuel Tank Calibration” screen. The sensor counts are then converted to a fuel
level based on the calibration data in the “Fuel Tank Calibration” screen.
A. Symptom: An “Err” is displayed for the digital value. Also, you may have an inaccurate, jumpy or zero
reading.
1. Problem: The IMC is mis-wired.
a) Action:
Measure the voltage on the three wires at the IMC Module (Red wire = +5 volts,
Black wire = ground, White wire = +2.5 volts).
Remove the Red wire from the IMC module and check the sensor counts on the “Fuel Tank
Calibration” screen increase. Be sure you are displaying the data for the correct tank.
Touch the wires between the IMC Module and the probe and check that the sensor counts
increase.
2. Problem:
The P-300 Fuel Probe is shorted or there is water or contamination in the tank.
a) Action: Remove the wire from the IMC Module to the center terminal of the P-300 probe. Ohm
the center terminal of the P-300 probe to ground. Check for > 10 M Ohms. Remove the probe from
the tank to resolve any issues.
7.10 Voltage Problem:
Bus voltage is measured on EDC pin 35 of the top connector.
A. Symptom: Inaccurate, jumpy or zero reading.
1. Problem: Pin 35 on the EDC top connector is mis-wired.
a) Action: Measure the voltage on pin 35 (look for bus voltage).
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