357 

 
No. 261 Leaking of sunroof (water on internal decoration of roof)   

Malfunction Cause 

Solution 

1) Uneven clearance around 
glass of sunroof and opening of 
roof  

1) Check if one side of the clearance between glass of sunroof and roof is 
too big; if so, dismantle left and right decorating bars for sunroof and release 
fastening bolt for glass; insert shim to the clearance around glass of sunroof 
and roof to even the clearance;   

2) Clog-up of sunroof drain   

2) Check drain for clog-up; if so, the drain should be cleaned;   

Water on 
internal 
decoration of 
roof 

3) Dropping-off of sealant at rear 
drain  

3) Check sealant at rear drain for dropping-off; if so, the rear drain should be 
re-installed;  

 

 

Leaking of sunroof (water in internal decoration 
of roof) 

One side of the clearance between 
glass of sunroof and roof is too big 

Adjust the clearance around 
glass of sunroof and roof evenly 

Clog-up of drain 

Clear the drain 

Dropping-off of sealant at rear 
drain 

Re-install rear drain

 

Unblocked 

Even 

Too-big 

Clog-up

Drooping-off

 
 

 

 

358 

 
No. 262 Air-conditioner can’t work   

Malfunction Cause 

Solution 

Undercharge of refrigerant   

Undercharge of refrigerant results in insufficient refrigerating capacity;   

Overdose of refrigerant   

Undercharge or overdose of refrigerant results in insufficient refrigerating 
capacity;  

Air in system   

Air in system results in insufficient refrigerating capacity;   

Leakage in system   

Check and remove leakage in system;   

Over-loose belt for 
compressor  

Over-loose belt for compressor results in over-low rotating speed of 
compressor, warm air outlet and abnormal sound; stretch or replace the belt; 

Open-circuit of AC pressure 
switch  

Replace AC pressure switch;   

Clog-up of drying filter   

Replace AC clog-up of drying filter;   

Less amount of cooling air for 
condenser  

Less amount of cooling air for condenser results in over-pressure at LP and 
HP side; check if the rotating speed of fan is normal and if the voltage is low; 

The fins of condenser is 
blocked by dust   

Blocked fins of condenser by dirt results in over-high HP and bad heat 
radiating effect; clean the dust on condenser;   

Dirt in system   

Dirt in system will result in vacuum or very low pressure at LP side, high 
pressure at HP side, frost or dew deposited on pipeline near drying reservoir 
or heat expansion valve and warm air outlet; if the condition is not improved 
after power-off, then it can be determined that the system is clogged up by 
dirt. Then the drying reservoir should be replaced and heat expansion valve 
should be cleaned;   

Moisture in system   

After certain working duration, moisture in system will result in obvious lower 
and lower pressure at LP side, clog-up of hest expansion valve by ice, frost 
deposited on evaporator and warm air outlet; and system will be normal if 
power-on again after certain duration of shut-down; but the malfunction of 
intermitting cooling will occur repeatedly;   

Low rotating speed or failure of 
blower  

Low rotating speed or failure of blower will result in frost deposited on 
evaporator, warm air outlet and insufficient refrigerating capacity; check 
blower speed adjusting switch, relay and speed adjusting resistance for 
damage and replace it, or replace blower assembly if necessary;   

Electromagnetic clutch of 
compressor is slipping   

Slipping of compressor electromagnetic clutch will result in abnormal running 
of compressor and insufficient refrigerating capacity; electromagnetic clutch 
can be replaced separately or compressor will be replaced;   

Too much refrigerating oil in 
system  

Too much refrigerating oil in system will result in turbid streaking on sight 
glass and insufficient refrigerating capacity; discharge exceed refrigerating 
oil;  

Air inlet duct of AC is clogged 
by other object   

Clogging of air inlet duct by other object will decrease air amount and result in 
insufficient cooling capacity and increased noise; clear clogging object from 
air duct;   

Fresh air damper of AC is not 
closed tightly   

Unclosed fresh air damper of AC will result in higher temperature of air outlet 
and insufficient refrigerating capacity; check the cause of unclosed fresh air 
damper and treat it;   

Air filter screen of evaporator 
is blocked by dust or other 
object  

Blocking of air filter screen of evaporator by dust or other object will result in 
decreased air amount and insufficient refrigerating capacity; clean air filter 
screen;  

The fins of evaporator is 
blocked by dirt   

Blocking of fins of evaporator by dust will result in decreased air amount and 
insufficient refrigerating capacity; clean it by compressed air;   

Malfunction of evaporator   

Malfunction of evaporator will resulting in failure of AC;   

Bad packing of temperature 
wrap for heat expansion valve   

Bad packing of temperature wrap for heat expansion valve will result in 
loosing of heat isolating layer and insufficient refrigerating capacity; pack it 
properly again;   

Incorrect adjusting of 
temperature controller   

Incorrect adjusting of temperature controller; replace the temperature 
controller;  

 

Air-conditioner 
can’t work   

Exceed  or  less  opening  of  Replace expansion valve assembly, pump for vacuum and fill refrigerant;   

 
 

 

 

359 

expansion valve   

Malfunction of compressor   

Malfunction of compressor will resulting in failure of AC;   

Short-circuit or break of loop 
and harness   

Check and repair loop and harness;   

Malfunction of engine ECU   

Replace engine ECU;   

 
 

 
 

 

 

360 

Air or moisture in system 

Air-conditioner can’t work 

Dirt in system 

Malfunction of air duct 

Undercharge or overdose of 
refrigerant

Repair or clear 

Check, repair or replace

Check and 
repair 

Malfunction of evaporator 

Too much refrigerating oil or dirt in system 

Electromagnetic clutch of compressor is slipping or belt is 
loosing

Malfunction of blower 

Malfunction of condenser or 
evaporator 

Malfunction of temperature controller 
or temperature wrap

Malfunction of 
compressor 

Check and repair

 

Check and repair 

Check, repair or 
replace

Check, repair or 
replace 

Check, repair or 
replace

Check, repair or 
replace

Check, repair or 
replace 

Check and 
repair

 

Short-circuit or circuit of circuit 
and harness 

Malfunction of engine ECU 

Check and repair loop 
and harness;

Replace engine ECU

Normal 

Abnormal 

Normal 

Normal 

Normal 

Normal 

Normal 

Normal 

Normal 

Normal 

Normal 

Normal 

Normal 

Abnormal 

Abnormal 

Abnormal 

Abnormal 

Abnormal 

Abnormal 

Abnormal 

Abnormal 

Abnormal 

Abnormal 

Abnormal 

Abnormal