Engine JAC HFC4DA1-2C. Manual - part 33

Maintenance manual for sunray hfc4da1-2c china-IV diesel engines 

 

131

Terminal ECU 

 

 

A06 

Power supply terminal of common rail pressure sensor 

 

A52 

Signal terminal of common rail pressure sensor 

 

A40 

Ground terminal of common rail pressure sensor 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Maintenance manual for sunray hfc4da1-2c china-IV diesel engines 

 

132

 

Fault Tree: 

 

 

 

 

 

 

 

 

 

 

 

Read DTC. 

Fault of fuel metering unit 

Repair accordingly. 

Check the common rail pressure 

sensor. 

Fault of common rail pressure 

sensor 

Repair accordingly. 

Repair accordingly. 

Fault of the low pressure oil 

circuit 

Fault of the high pressure oil 

circuit 

Repair the harness. 

Get the Technical Support. 

Check the low pressure oil circuit 

by referring to fault tree of “Low 

Pressure Oil Circuit”. 

Maintenance manual for sunray hfc4da1-2c china-IV diesel engines 

 

133

Inspection for Low Pressure/Hig

h Pressure Oil Circuit:   

 

Low pressure oil circuit 

Check fuel tank supply. Only checking the fuel tank 

level indicator is not enough, for its indication may 

be invalid. 

Is there no fuel in the fuel tank? 

Add fuel. 

Check the status and function of manual pump. 

Fault of manual pump 

Repair accordingly. 

Visually inspect the low pressure pipeline (leakage, 

coordination, connection) 

Repair accordingly. 

Fault of low pressure pipeline 

Ensure there is no air bubble in the low pressure oil 

circuit. 

Is there air in the oil circuit? 

Find out where the air comes from 

and repair the system, and then clean 

the fuel pipe.   

Ensure the diesel filter model and the connection of 

fuel inlet and outlet are correct. 

Incorrect signal or connection 

 

Replace the current filter with the 

original one or connect the inlet and 

outlet pipes of filter correctly. 

Repair accordingly. 

High pressure oil circuit 

Make diagnosis for the high pressure oil circuit in 

strict accordance with the diagnostic procedures for 

high pressure oil circuit. 

Is there any problem? 

The high pressure oil circuit is intact. 

Maintenance manual for sunray hfc4da1-2c china-IV diesel engines 

 

134

4.   

DTC 

P0116 

The dynamic characteristics of coolant temperature sensor are unreliable. 

 P0117 

The coolant temperature sensor output voltage is below the lower limit (the 
wiring is short to ground). 

 P0118 

The coolant temperature sensor output voltage is above the upper limit (the 
wiring is open or short to high level). 

 

P0119 

The static characteristics of coolant temperature sensor are unreliable. 

 

 

Fault Description: The engine coolant temperature (ECT) sensor is a kind of negative temperature coefficient 
variable resistor, which can measure the engine coolant temperature. Its resistance shall decrease with the increase of 
temperature, so the signal value input into ECU in the form of voltage shall decrease accordingly. The voltage signal 
range is 0-5V. The ECU searches the characteristic curve of the sensor and converts it into engine coolant temperature. 
The diagnostic module of engine coolant temperature sensor shall make fault judgment based on this temperature 
value. The ECU shall supply 5V voltage to the signal circuit of engine coolant temperature sensor and also supply 
grounding for the low reference voltage circuit. If the signal voltage of engine coolant temperature sensor detected by 
ECU is too low (indicating the temperature is too high), or too high (indicating the temperature is too low), relevant 
DTC shall be generated. 

The following table illustrates the difference among temperature, resistance and voltage. 

Engine coolant temperature 

Resistance of coolant temperature 

sensor 

Signal voltage of coolant temperature 

sensor 

Low High High 

High Low Low 

Diagnosis Hint: 

Overheating may result in generation of this DTC. After the engine is started, the temperature of engine coolant 
temperature sensor should increase steadily and become stable after the thermostat is disconnected. Test the engine 
coolant temperature sensor under different temperature to check for any error of sensor. If any, the error may result in 
failure of control performance. After the engine is laid up for a night, the indication difference between IAT sensor and 
engine coolant temperature sensor should be within 3°C (5°F). Refer to “Temperature and Resistance”.   

Check for the following conditions: 

Poor contact between ECU and engine coolant temperature sensor – Check the harness connector for: 

− Loose terminal 

− Poor matching and connection 

− Breakage of keeper 

− Distortion or damage of terminal 

Coolant temperature 

sensor 

Coolant temperature 

signal (High) 

Coolant temperature 

signal (Low)