(c)  Clear DTC code. 

(d)  Start and run the engine at idle speed to warm up the engine for at least 5 min. 

(e)  Read control system DTC code again to confirm that the system has no DTC code exported. 

 

8 Troubleshooting 

5. Maintenance 

guide 

: 

Refer to “2.4.8.1 Replacement of Canister Solenoid Valve” to replace the canister solenoid valve. 

No 

Refer to 2.2.7.3 Intermittent Fault 
Inspection for intermittent fault. 

Yes 

271

2.2.7.40 DTC P0480 P0481 

1. DTC 

description: 

DTC  P0480 

Low-Speed Fan Malfunction 

 

DTC  P0481 

High-Speed Fan Malfunction 

High or low speed cooling fan relay coil power is provided by ECM controlled main relay. ECM 
controls the relay via ECM harness connector EM01 terminal No.65 and 17. Drive circuit is 
equipped with a feedback circuit to ECM. Drive circuit is equipped with a feedback circuit to 
ECM. ECM monitors the feedback voltage control circuit to determine whether the control circuit 
is open, short to ground or short to voltage. 

2.  Conditions For Setting DTC and The Fault Location: 

DTC Code 

DTC Detection 
Strategy 

Conditions For Setting The DTC 
(Control Strategy) 

Fault Locations 

P0480 

P0481 

Hardware Circuit 
Inspection 

Fan 1 control circuit open or shot, 
reported as DTC code. 

1. Relay 

Circuit 

2. Relay 

3. ECM. 

4. Cooling 

Fan 

3. Circuit 

figure 

Refer to 2.2.6 Electrical Schematic Diagram 

4. Diagnostic 

Steps: 

Refer to 2.8.7.2 Cooling Fan Circuit Diagnosis 

5. Maintenance 

guide 

: 

Replace the cooling fan. Refer to 2.8.8.3 Replacement of Cooling Fan. 

272

2.2.7.41 DTC P0502 

1. DTC 

Description: 

DTC  P0502 

No signal from vehicle speed sensor 

The vehicle speed signal is used to monitor the vehicle speed. The vehicle speed signal is one of 
the fuel control reference signals during an urgent deceleration. Input through the terminal 51 of 
ECM harness connector EM21 and further transmit to the instrument at the same time. The vehicle 
speed sensor signal is sent to the instrument panel used for the vehicle speed display. 

2.  Conditions For Setting DTC and The Fault Location: 

DTC Code 

DTC Detection 
Strategy 

Conditions For Setting The DTC 
(Control Strategy) 

Fault Locations 

P0502 

No signal from 
vehicle speed 
sensor 

1.  Under hot operating conditions, 

driving the vehicle at Low-Speed 
at 3rd gear, Disconnect the 
vehicle speed sensor. and then 
press the acceleration pedal hard 
to accelerate to higher than 4,000 
and immediately release the 
pedal. Engine speed, vehicle 
speed and MAP values begin to 
decline. When entering the fault 
setting window, DTC code will 
be set. 

2.  Under hot operating conditions, 

driving the vehicle at medium 
speed at 4th gear, Disconnect the 
vehicle speed sensor. and then 
press the acceleration pedal to 
accelerate the vehicle. Engine 
speed, vehicle speed and MAP 
values entering the fault setting 
window, DTC code will be set. 

1. Vehicle  Speed 

Sensor 

2. Vehicle  Speed 

Sensor Circuit 

3. ECM. 

 

273

3. Circuit 

sketch 

1

3

2

EM01

51

IP02

8

IP02

12

车速传感器

VSS

发

动

机
控

制

模

块

组

合

仪
表

8V POWER

SPEED

IN

OUT

NL02-0058c

 

4. Diagnostic 

Steps: 

1 

Road test the vehicle. Is the vehicle speed displayed on the instrument working 
properly? 

A  If the instrument displays the vehicle speed as per normal, the vehicle speed sensor is 

working correctly. 

B.  If the instrument displays the vehicle speed abnormally, the vehicle speed sensor or the 

circuit may be faulty. 

 

2 

Inspect the vehicle speed sensor power supply circuit. 

 

No 

Go to step 4 

Yes 

Speed sensor 

Combinat

ion 

instrument 

Engine contro

l 

module 

274