Sym Fiddle III 50 Service Manual page 127

4. ELECTRONICALLY CONTROLLED CARBURETOR SYSTEM
Pin plug
Upper
Centre
Lower
Testing Procedures:
1 . Use probe tool to connect or remove the sensor, the working voltage can be measured.
2. Turn on the main switch, but don't start the engine.
3. Use "Multi-meter" direct current range, inspect the sensor resistance.
4. Working voltage confirmation
The cathode voltage-connect to the third pin of sensor（green/red）
The anode voltage+ connect to the second pin of sensor（yellow/black）
5. Confirm the output signal of throttle (use probe tool）
The cathode voltage-connect to the third pin of sensor（green/red）
The anode voltage+connect to the first pin of sensor（white/brown）
Measuring the output voltage while the throttle fully closed and fully open
Detection judge:
Working voltage value 5.0±0.1V.
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Fully closed the output voltage values of throttle: 0.7±0.1V.
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Fully opened the output voltage values of throttle: 3.9±0.1V.
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Throttle position sensor standard inspection (use diagnostic software)
The output signal of throttle using the diagnostic software on the computer
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Confirm the output signal of throttle—fully closed
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Connect the diagnostic software with the vehicle and turn on the main switch but don't start the engine.
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Don't rotate the throttle, view the APP PID of throttle position sensor whether it is correct.
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Confirm the output signal of throttle—fully opened
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Connect the diagnostic software with the vehicle and turn on the main switch but don't start the engine.
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Rotate the throttle fully opened, view the APP PID of throttle position sensor whether it is correct.
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Treatment of abnormal phenomena:
The throttle position sensor is damage, or adapter connector poor contact.
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Check whether there is any abnormal on main distribution line.
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When the throttle position sensor is abnormal, suggest to replace new throttle position sensor and
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recheck it.
Cautions
It's forbidden to remove the throttle position sensor to be tested from the carburetor.
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4-8
Wire color
white/brown The signal input
yellow/black Input 5v voltage
green/red
Function
Earth wire
SYM