121 

No.067 JL376/378QE engine’s electric control system check   

Testing 
step 

Testing terminal   

Component, part check   

Preparations for testing conditions   

Rated value   

01 

 

Sealing of intake system 

Ignition closed, take out plug of controller, and intake pipe in front of throttle valve is sealed with 
proper materials. Take out connecting pipe of canister control valve of throttle vavle body. 
Apply compressed air, and make pressure within intake pipe as about 1-2bar. Check liquid 
leaking, and check all sealing seams. After check, reassemble connecting  pipe of canister 

No generation of bulb   

02  

Fuel 

device 

 

Ignition closed, take out plug of controller, and connect pressure gauge at fuel high-tension 
loop. Take out fuel return pipe of the pressure regulator, and install auxiliary hose on the 
connector of pressure regulator. And auxiliary hose leads to one proper barrel (with capacity of 
at least 2 liters). 46 and 3 pins on the controller are earthed at the same time, making oil pmp 
rotate 30 seconds.     

 

02.1 

 

Oil supply of fuel pump 

Carry out same as step 02 

700-1000ccm 

02.2  

Fuel 

pressure 

 

Carry 

out same as step 02 

2.8—3 bar 

02.3 

 

Oil return pipe   

Remove auxiliary hose, and connect return pipe to oil tank, and ignition is switched on, and 3 
and 46 terminals of controller plug are earthed  (with auxiliary cable). Read out pressure of 
pressure gauge, and disconnect earth connection, and ignition is closed. 

Max. 2.9—3.1 bar 

02.4  

pressure 

maintenance 

After about 10 seconds, read pressure of the monograph again, and record dropped value of 
the pressure.   

0.2-0.3 bar 

02.5  

pressure regulator 
function  

Plug in the controller, and the engine will start and operate at idling speed. Record fuel 
pressure at idling speed, and increase the throttle, and meanwhile observe pressure gauge, 
and pressure must be increased 

About 2.5 bar, 
 
 
About 2.8 bar

02.6 

 

Power supply of fuel pump

Ignition closed, and take out controller plug, and connect the voltmeter to plug of fuel pump, 
and make 3 and 46 terminals of controller plug earthed at the same time (with auxiliary cable). 
And fuel pump must be operating, and read out power supply voltage.   

Min. 10.7V 

 
 

 

122 

02.7  

Voltage drop of anode 
side 

Same as description of 02.6, but multimeter placed to another terminal.   

Max. 0.5V 

02.8  

Voltage drop of cathode 
side 

Same as description of 02.6, but multimeter placed to another terminal. 

Max. 0.5V 

02.9 

 

Total value of voltage drop Values calculated based on 02.7 and 02.8.   

Max. 0.8V 

03.0  

Earth connection

of 

constant anode to 
controller 

Ignition closed, take out controller plug and connect multimeter   

 

03.1 18．．．2 

Constant anode, earthing 
terminal 2 

Carry out same as step 3.0 

About 12V 

03.2 18. 

14 

Constant anode, earthing 
terminal 14 

Carry out same as step 3.0 

About 12V 

03.3 18． 19 

Constant anode, earthing 
terminal 19 

Carry out same as step 3.0 

About 12V 

03.4 18…24 

Constant anode, earthing 
terminal 24 

Carry out same as step 3.0 

About 12V 

04.0  

Anode to controller earth 
connection, voltage drop 
ignition switch 

Ignition closed, take out controller plug, load resistance and voltmeter connection   

＜

0.3V 

04.1 

B+    18 

Voltage drop terminal 18 

Load resistance terminal 18 and 2 

＜

0．3V 

04.2 

B-    2 

Earth wire terminal 2 

Load resistance terminal 18 and 2 

＜

0．3V 

04.3 

B-    4 

Earth wire terminal 4 

Load resistance terminal 18 and 4 

＜

0．3V 

04.4 

B-    19 

Earth wire terminal 19 

Load resistance terminal 18 and 19 

＜

0．3V 

04.5 

B-    24 

Earth wire terminal 24 

Load resistance terminal 18 and 24 

＜

0．3V 

04.6 

B+    27 

Voltage drop terminal 27 

Load resistance terminal 18 and 27, ignition turned on   

＜

0．3V 

04.7 

B+    37 

Voltage drop terminal 37 

Load resistance terminal 18 and 37, ignition turned on 

＜

0．3V 

05.1 

Hall sensor 1...3 

Power supply hall sensor  Ignition closed, controller plug inserted. Connect voltmeter, and turn on ignition. About 

5 

 
 

 

123 

05.2 

Hall sensor 1...2 

Hall sensor signal   

Close ignition, insert controller plug and connect  voltmeter. Take out socket connector of 
ignition coil with ignition switch, and take out distributor cover. With ignition turned on, slowly 
rotate belt pulley of engine crankshaft manually, and observe shading rotor of measuring 
instrument and hall sensor. 

When replacing shading 
rotor, one voltage larger 
than 2V must be displayed 

05.3 

Hall sensor based on 
terminal 12 and ECU 

To anode conductor 
connection of hall sensor

Close ignition, take out controller plug and connect the multimeter. 

＜

0.5Ω 

05.4 

Hall sensor based on 
terminal 48 and ECU 

To cathode conductor 
connection of hall sensor

Same as Step 5.3, with multimeter connected to another terminal 

＜

0.5Ω 

05.5 

Hall sensor based on 
terminal 49 and ECU 

Connection from hall 
sensor to controller 
conductor 

Same as Step 5.3, with multimeter connected to another terminal 

＜

0.5Ω 

06.1 

Pressure sensor terminal 
3...1 

power supply from intake 
pipe pressure sensor 

Ignition closed, and connect controller. Connect the voltmeter to plug of pressure sensor, and 
ignition turned on 

约

5 

06.2 

Pressure sensor terminal 
4...1 

Intake pipe pressure 
sensor signal   

Same as Step 6.1, with voltmeter connected to another terminal 

3．8V  4.2V 

06.3 

Pressure sensor terminal 
4...1 

Intake pipe pressure 
sensor signal when the 
engine is no-load running

Same as Step 6.2, with engine running at idling speed   

10.8V 
1.3   

06.4 

Pressure sensor terminal 
4...1 

Intake pipe pressure 
sensor signal when 
increasing throttle 

  Same as Step 6.2; step on the throttle, and observe voltmeter   

电压变化

 

06.5 

Pressure sensor terminal 
3 and ECU terminal 12 

Anode conductor 
connection to pressure 
sensor 

Ignition closed, take out controller plug, and connect resistance and measure   

＜

0.5Ω 

06.6 

Pressure sensor terminal 
1 and ECU terminal 30 

Cathode conductor 
connection to pressure 
sensor 

Same as Step 6.5; connect multimeter   

＜

0.5Ω 

06.7 

Pressure sensor terminal 
4 and ECU terminal 7 

Signal conductor 
connection to controller 

Same as Step 6.5; connect multimeter 

＜

0.5Ω 

07.1 

Pressure sensor terminal 
1...2 

Power supply from intake 
temperature sensor   

Close ignition, connect controller plug, and take out connection of socket connector of pressure 
sensor, and connect voltmeter to plug of pressure sensor, ignition     

About 5V 

07.2 

Pressure sensor terminal 
1...2 

Intake temperature sensor 
signal  

Same as Step 07.1, connect plug of pressure sensor. Note: this value is related to temperature 0.5…3V 

07.3 

Pressure sensor terminal 
1...2 

Intake temperature sensor 
resistance  

Close ignition, take out plug of pressure sensor. Connect multimeter of pressure sensor. Note: 
this value is related to temperature 

At 20   

 
 

 

124 

07.4 

Pressure sensor terminal 
2 to controller terminal 44 

Intake temperature sensor 
signal conductor   

Close ignition, take out controller plug, and connect multimeter   

＜

0.5Ω 

08.1 

Throttle position sensor 
terminal 1..2 

Power supply from throttle 
sensor  

Close ignition, connect controller plug, and connect voltmeter, ignition turned on 

About 5V 

08.2 

Throttle position sensor 
terminal 2..3 

Throttle sensor signal 
voltage, throttle closed, 
throttle sensor signal 
voltage 

Same as Step 8.1, voltmeter connected to throttle, closed 

0.1…0.9V 

08.3 

Throttle position sensor 
terminal 2..3 

Throttle all opened   

Same as Step 8.2, whole throttle opened 

3.0…4.8V 

08.4 

Throttle position sensor 
terminal 2..3 

Throttle sensor signal 
voltage inspection. Note: 
this inspection only 
possible with connecting 
one oscillograph 

Same as Step 8.2, but connect one oscillograph to replace voltmeter, with throttle quickly 
opened and closed sever 

Oscillograph without 
voltage interference   

08.5 

Throttle position sensor 
terminal 1 and ECU 
terminal 12 

Connection between 
anode conductor to 
throttle sensor   

Close ignition, take out controller plug, and connect resistance and measure   

＜

0.5Ω 

08.6  Throttle position sensor 

terminal 2 and ECU 
terminal 30 

Connection between 
cathode conductor to 
throttle sensor 

Same as Step 8.5, with multimeter connected to terminal   

＜

0.5Ω 

08.7  Throttle position sensor 

terminal 3 and ECU 
terminal 53 

Signal conductor to 
controller conductor   

Same as Step 8.5, with multimeter connected to terminal 

＜

0.5Ω 

09.1 

Knocking sensor terminal 
2 and ECU terminal 30 

Cathode conductor to 
controller conductor   

Close ignition, take out controller plug, and connect multimeter   

＜

0.5Ω 

09.2 

Knocking sensor terminal 
1 and ECU terminal 11 

Connection between 
signal conductor to 
controller  

Same as Step 9.1 

＜

0.5Ω 

09.3 

Knocking sensor terminal 
3 and ECU terminal 19 

Shielded conductor 
connection  

Same as Step 9.1, with multimeter connected to another terminal   

＜

0.5Ω 

09.4 

Knocking sensor terminal 
1…2 

Internal resistance of 
knocking sensor   

Disconnect socket connector of knocking sensor, and connect multimeter   

4.5…5.5V 

10.1 

Oxygen sensor terminal 
1…2 

Power supply for heating 
element of oxygen sensor 

Close ignition, plug in controller, with voltmeter connected to two white conductors connecting 
to socket connector of oxygen sensor, and start the engine to be running at idling speed   

12...14V 

10.2 

Oxygen sensor terminal 
1…2 

Internal resistance of PTC 
heating element   

Close ignition, and disconnect socket connector of oxygen sensor, and connect multimeter to 
two white conductors of oxygen sensor. Note: this value is related to temperature.   

0.2...20 

10.3 

Oxygen sensor 1…2 

Current  consumption  of  Close ignition, ampere meter with suitable commutator conductor, connecting to one white