397 

valves to judge the breakdown of the refrigeration system. The inspection shall be made when the air 
temperature is between 30 ~35oC and the engine speed is 2000r/min. The fan wind speed is adjusted to the 
high gear and the temperature is adjusted to the Max. refrigerating gear. The normal condition is that: the 
pressure at the high-pressure side is 1.2Mpa ~ 1.8Mpa and that at the low-pressure side is 0.15 Mpa ~ 
0.20Mpa; the system may have a failure if it is out of this scope. 7). Other inspection methods 
(1) Condenser: the thermometer is used for thermometer under normal operation. When the condenser air-in 
temperature is about 35oC, the air-out temperature shall be about 55oC.   
(2) Continual reduction of the air volume at the air outlet means the frosting on the evaporator surface.   
(3) Dry reservoir: inconsistency of the temperature on upper and lower side of the dry reservoir shell means 
there is the block inside the dry reservoir.   

Maintenance and diagnoses of electronic power-assisted steering system 

No.291 Line inspection of "EPS" indicating lamp (the "EPS" indicator 

does not light up when the ignition switch is opened)   

 

1. Battery 
2. Main fuse 
3. Ignition switch 
4. Circuit fuse (15A) 
5. Control module 
6. EPS lamp 
7. Main fuse 
8. Control box socket 
9. Connector 

Step Operation 

Yes 

No 

 

1 

Are the main fuse and the line fuse in good condition 
or not ? 

Go to step 2 

The main fuse and the line fuse is 
broken 

 
 

2 

1.    Turn on the ignition switch 
2.    Inspect the voltage between the terminal "A6" 
and the module case earthing 
3、Is it the battery voltage?   

Go to step 3 

“B/W” wire is broken or short circuit 

 
 

3 

1.    Check the voltage between the terminal "A8" and 
the module case earthing 
2. Is it the battery voltage?   

Go to step 4 

"B/R" wire is broken or short circuit 

 
 
 
 

4 

1. Turn off the ignition switch and disconnect the 
connector 8 from the control module 
2.    Disconnect the body ground terminal "A3" on the 
connector "8" body 
3.    Turn on the ignition switch again, is the "EPS" 
lamp light up?   

Go to step 5 

The bulb is burnt out or the "V/G" wire is 
broken 

 
 
 

5 

1.    Is the connection between the connector "8" and 
the control module  firm?  

Terminal “A6”，“A7”
" A3 " or " A8 " is in 
poor contact; the 
control module case 
is in poor earthing; 
"B" wire 
+12V is broken 

Poor connection 

 
 

 

 

398 

No.292 Inspection to "EPS" indicator line ("EPS" indicator does not 

light up or keep on lighting up when the cross-line connection is made 

between the diagnoses switch terminal and the ground terminal)   

Step Operation 

Yes 

No 

 

1 

1.    If terminal "A2" of the connector "9" is perfectly connected to 
the control module 

Go to step 2 

Poor contact 

 
 

2 

1. Earth the "A2" terminal by wire under the condition that the 
connector is connected with the control module 
2. Turn on the ignition switch, is the "EPS" lamp flicking?   

1、The maintenance line 
is broken 
2、.    "B/W" line is broken 
or "B" line is in poor earth 

Recheck it with replaced 
control module 

No.293 Main line of DTC11 torque sensor (the main line is broken or 

short circuit)   

Step Operation 

Yes 

No 

 
 
 
 

1 

1、Remove the protective cover of the steering column hole
2、 Turn on the ignition switch and put the steering wheel 
towards the right front direction of the vehicle, and check if 
the terminal voltage of the torque sensor bar foot center "B5" 
wire is about 2.5V.   

1. "W" wire is broken 
2. Terminal "B5" is in poor 
connection 
3. Recheck it with replaced 
control module if the above 
conditions are normal 

Go to step 2 

 
 

2 

1. Close the master switch and disconnect the torque sensor 
rod head 
2. Check the resistance between terminals "B5" and "B2" of 
the torque sensor 
3. Whether it is about 0.96kΩ 

1. "W" wire to the battery is 
short circuit or earthed 
2. The torque sensor connector 
is in poor contact with the line 

The torque sensor has 
defects 

No.294 DTC13 torque sensor (there is big difference between the 

auxiliary line outputs of the main line and the torque sensor)   

Step Operation 

Yes 

No 

1. Remove the protective cover of the steering column hole 
2. Turn off the ignition switch and disconnect the torque sensing unit 
3、 Inspect the resistance between the torque sensor side plug-in unit 
terminals according to the following state

About  0.96 KΩ 

The steering wheel faces 
towards right ahead 

About  0.48 KΩ 

The steering wheel steers 
entirely 
right 

“R—B” 

About 1.02 KΩ 

The steering wheel steers 
entirely 
Left 

1 

“R—W” 

About  0.96 KΩ 

The steering wheel face 
towards right ahead 

1"W" or "B" lines are in 
poor condition 
2. Terminals "B5" or 
"B4" are in poor 
connection 
3. Recheck it with 
replaced control module 
if the above conditions 
are normal   

The torque 
sensor is 
broken down 

 
 

 

 

399 

About  1.02 KΩ 

The steering wheel steers 
entirely 
Right 

About  0.48 KΩ 

The steering wheel steers 
entirely 
left 

No.295 DTC14 torque sensor (power supply voltage of the torque 

sensor is too high or too low)   

Step Operation 

Yes 

No 

1 

1）Remove the protective cover of the steering column hole
2）Turn on the ignition switch and check the voltage between 
"R" wire of the torque sensor connector and the terminal 
ground 
3）Is it about 5V? 

Recheck it with replaced control 
module 

Go to step 2 

2 

1）Turn off the ignition switch and disconnect the torque 
sensor connector 
2） Check the resistance between "R" wire of the torque 
sensor connector and the terminal ground 
3）Is it about 1.09 KΩ?  

1） Terminal "B2" or "B3" is in 
poor connection 
2）  Harness of the torque sensor 
plug-in unit is in poor contact 
3) "R" or "G" line is disconnected 
4） "R" or "G" line is grounded and 
the battery are short 

The torque sensor 
is broken down 

No.296 Auxiliary line of DTC15 torque sensor (the auxiliary line is 

disconnected or short circuit)   

Step Operation 

Yes 

No 

1 

1）Remove the protective cover of the steering column hole
2）  Turn on the ignition switch and put the steering wheel to 
the front moving position of the vehicle; check the voltage of 
"B" terminal on the torque sensor connector.   
3）Is it about 5V?   

1）"B" wire is disconnected 
2）Terminal "B4" is in poor contact 
3）Recheck it with replaced control 
module if the above conditions 
are normal   

Go to step 2 

2 

1）Turn off the ignition switch and disconnect the torque 
sensor connector.   
2）Check the resistance between "R" wire and "W" wire or 
between "R" and "B" terminals on the torque sensor 
connector 
3）Is it about 0.96 kΩ?  

1）"B" wire is ground or the battery 
is short 
2）The torque sensor connector is 
in poor contact with the harness 

The torque sensor 
is broken down 

No.297 DTC22 engine speed signal (no engine signal input)   

Step Operation 

Yes No 

1 

Does the tachometer display the engine speed 
signal?  
0-1V 

Go to step 2 

1）The connector is in poor 
connection or the line is 
broken 
2 ）  There is no rotation 
speed signal output in ECU

 
 

 

 

400 

2 

1 ） Remove the control module and connect the 
control module connector when the ignition switch is 
off.  
2）Check the voltage between "A4" terminal of the 
control module and the earthing when the ignition 
switch is on; check the resistance between "R" line of 
the torque sensor connector and the terminal ground
3）Is it 8~12V?   

"A4" is in poor connection; 
replace with a good control 
module if the connection is 
normal 

"Br" line is broken