Page 590 - Foton Workshop Manual - Tunland (AT)

04-444 DIAGNOSTICS - ENGINE CONTROL SYSTEM

THE ENGINE FAN DOESN'T WORK, WORKS UNSTEADILY OR

WORKS CONTINUOUSLY

Fault phenomenon Diagnosis logic Possible reasons

• Fan fault
• Fan
04 • Air conditioner circuit fault
The engine fan doesn't work, • Air conditioner circuit • Fan control circuit fault
works unsteadily or works • Fan control circuit • Coolant temperature sensor
continuously • Coolant temperature sensor
fault
• ECM
• ECM fault

Diagnosis Procedure

1 . Check the engine data
(a) Ignition switch: OFF.
(b) Connect the diagnosis tool with the fault diagnosis connector (16 pins) on the lower
left of the dashboard.
(c) Ignition switch: ON, and start the diagnostic tool.
(d) Read the motor data shown on the diagnostic tool.

Check whether the data flow is normal or not.
YES>To step 2.

No >Maintenance related faults.

2 . Check coolant temperature sensor
(a) Check whether the coolant temperature sensor is installed correctly.
(b) Remove the coolant temperature sensor
(c) Check whether the sensing hole is blocked or not, and whether the resistance between
the terminals is in line with the standard or not.
(d) Check whether the coolant temperature sensor is dirty.
(e) Ignition switch: ON, and read the data flow of the coolant temperature sensor shown
on the diagnostic tool.

Is the inspection result normal?
YES>To step 3.

No >Maintenance related faults.

3 . Check the fan or its circuit
(a) Check whether the fan is damaged or not.
(b) Check whether the fan control circuit is abnormal or not.

Is the inspection result normal?
YES>To step 4.
No >Maintenance related faults.

4 . Check the air conditioner and its circuit
(a) Check whether the air conditioner is damaged or not.

Page 590