401 

No.298 Vss line (Vss line is disconnected or short circuit) 

DTC21Vss line (the engine runs at 2500 R.P.m or higher for continuous 60 seconds (the rotation speed is 
4000 R.P.m or higher when the engine is started) and there is no vehicle high speed signal input) 
DTC23Vss line (the engine runs at 2500 R.P.m or higher for continuous 60 seconds (the rotation speed is 
4000 R.P.m or higher when the engine is started) and there is no vehicle high speed signal input) 
DTC24Vss line (the engine is beyond the standard level for continuous 5 seconds/there is no vehicle speed 
input) 
DTC14 torque sensor (supply voltage of the torque sensor is too high or too low) 

Step Operation 

Yes 

No 

 
 

1 

Does the speedometer display the speed 
signal?  

1）"A5" is in poor connection with "V" 
harness 
2）Replace the control module to recheck if 
the connection is all right 

Replace with a good 
vehicle speed sensor 

No.299 DTC41 motor (the motor voltage is too high or too low)   

DTC43 motor (the motor current is too high) 
DTC42 motor (current displayed on the control module is of great difference from the current actually flowing 
into the motor) 
DTC44 motor (there is output signal in the control module, yet the motor doesn't start) 
DTC45 motor (current actually flowing into the motor is lower than that outputed by the control module) 
DTC14 torque sensor (supply voltage of the torque sensor is too high or too low) 

Step Operation 

Yes No 

1 

Is there DTC?   

Motor failure 

Go to step 2 

 
 
 

2 

1）Dismount the hole cover of the steering column
2）Disconnect the motor and the clutch connector 
when the ignition switch is OFF 
3）Check the conductivity between terminals of the 
motor 
4）Is it conductive?   

Go to step 3 

Motor failure 

3 

1)  Check the resistance between the motor and 
the clutch as well as the body ground 
2) Is it infinite?   

1）"R" or "B" line is disconnected 
2）"R" or "B" line is short to 
ground 
3 ） The connector is in poor 
contact 
4）Replace with a perfect control 
module to recheck provided the 
above phenomena are normal 

Motor failure 

No.300 DTC51 clutch line (the clutch line is disconnected or short)   

Step Operation 

Yes 

No 

 
 

 

 

402 

 
 
 
 

1 

1) Remove the hole cover of the 
steering column 
2) Disconnect the motor and the 
connector when the ignition switch is 
OFF 
3) Check the conduction between 
terminals of the clutch connector 
4）Is it conductive?   

Go to step 2 

Clutch failure 

 
 
 
 

2 

1) Check the resistance between the 
motor and the clutch connector as well 
as between the motor and the ground 
2) Is it infinite?   

1）"B/B1" or "B/R" line is disconnected 
2）"B/B1" or "B/R" to ground is short 
3）The motor and the clutch connectors are in poor 
contact 
4）"A9" and "A10" terminals are in poor contact 
5）Replace with a perfect control module to recheck 
provided the above phenomena are normal 

Clutch failure 

No.301 Power circuit of DTC54 control module   

(low voltage of the battery)   

Step Operation 

Yes 

No 

 
 
 

1 

1）Remove the control module and connect the control 
module connector when the ignition switch is off.   
2）Check the voltage between "A7" terminal of the 
control module and the ground when the ignition switch 
is ON.   
3）Is it 10-14V?   

1）"A7" terminal is in poor contact 
2) Replace with a perfect control 
module to recheck provided the 
above phenomena are normal.   

Battery failure 

No.302 DTC52 and DTC55 control modules (failure of control module)   

Replace with a good control module and recheck; Inspection to the control module and its line: the control 
module and its line can be inspected by measuring the voltage and the resistance of the module connector; 
The multi-meter is strictly prohibited to measure the control module under the condition of disconnecting the 
module connector.   

No.303 Voltage inspection   

1）Remove the control module from the body when the ignition switch is OFF 
2）Connect the control module connector to the control module 
3）Inspect each terminal voltage of the connector according to the following table 
4）Voltage of the battery is confirmed to be 11V or higher when the ignition switch is in ON position 

Terminal 

Line 

Normal voltage 

Malfunction symptom 

A6 

Voltage of the ignition switch control 

10-14V 

Engine operates at idle speed 

A5 

Vss 

0-1V and    4-6V 

The front left tire rotates greatly under the 
condition of ignition switch being ON and the 
front wheel being locked 

B2 

Power supply of the torque sensor 

About 5V 

Inspect the voltage between "B2" and B3 when 
the ignition switch is ON 

B1 Blank 

—— 

—— 

A3 

"EPS" failure indicating lamp 

0-2V, 10-14V 

"EPS" lamp lights up or off when the engine 
operates at idle speed 

 
 

 

 

403 

A9 

Clutch plus 

10-14 

The engine operates at idle speed and the 
steering wheel is fixed in straight ahead position 
of the vehicle 

A4 Engine 

signal 

—— 

—— 

B3 Torque 

sensor 

(GND) 

0V 

 

B4 

Torque sensor plus 

About 2.5V 

The engine operates at idle speed, direct 
moving direction, the voltage between "B4" and 
"B3" terminals 

B5 

Torque sensor minus 

About 2.5V 

The engine operates at idle speed, direct 
moving direction, the voltage between "B4" and 
"B3" terminals 

A10 Clutch 

minus 

0V 

—— 

A2 

Disconnect to the terminal 5V 

Ignition 

switch 

ON 

A11 

Motor output plus 

5-7V 

The engine operates at idle speed, the steering 
wheel is fixed to direct moving position of the 
vehicle 

A12 

Motor output minus 

5-7V 

The engine operates at idle speed, the steering 
wheel is fixed to direct moving position of the 
vehicle 

A7 

Power supply plus 

10-14V 

Engine operates at idle speed 

A8 Power 

supply 

minus 

0V 

—— 

A1 Blank 

—— 

—— 

 

No.304 Introduction of mechanical assembly   

1）The steering column assembly can not be disassembled. Provided any part is found to have defect, the 
whole assembly shall be replaced.   
2）It must be noticed not to cause the impact when the steering column assembly is replaced.   
Chart of connector functions 

 

 
 

 

 

404 

 

SN Line 

No. 

Name 

Load 

Color 

Dia. 

1 B1 

Blank 

— — — 

2 B2 

+5V 

5~10mA 

R 

0.5mm2 

3 B3 

GND 

5~10mA 

G 

0.5mm2 

4 B4 Torque signal 1 

<5mA B 0.5mm2 

5 B5 Torque signal 2 

<5mA W 0.5mm2 

6 A1 

Blank 

— — — 

7 A2 Diagnosis control 

<10mA B1/W 0.5mm2 

8 A3 Indicating lamp 

5~20mA V/G 0.5mm2 

9 A4  Engine speed 

<10mA Br 0.5mm2 

10 A5  Speed signal 

<10mA V 0.5mm2 

11 A6 

ON switch 

<10mA B/W 0.75mm2 

12 A7 

12V power 

<32A B/R 

2.5mm2 

13 A8  Power ground 

<32A B 

2.5mm2 

14 A9  Clutch plus 

<1A B/B1 

0.75mm2 

15 A10  Clutch minus 

<1A B/r 

0.75mm2 

16 A11 

Motor plus 

<30A R 

2.5mm2 

17 A12  Motor minus 

<30A B1 

2.5mm2