191Standard
NOTICE:
Connector should be disconnected when measured.
6. INSPECT WATER TEMPERATURE WARNINGLIGHT
(a) Disconnect the water temperature sensor connector.
(b) Turn the ignition ON, the water temperature warning light should go out.
(c) Ground the terminal B5 of the meter connector, the water temperature warning light should light up.
7. INSPECT OIL PRESSURE WARNING LIGHT
(1) Disconnect the oil pressure sensor connector.
(2) Turn the ignition ON, the oil pressure warning light should go out.
(3) Short connector terminal to the ground with a wire, the oil pressure warning light should light up.
8. INSPECT OIL PRESSURE SENSOR
(1) Disconnect the connector from the oil pressure sensor .
(2) Inspect continuity between its terminal and ground.
Engine is stopped: Continuity
Engine runs: No continuity
9. INSPECT PARK BRAKE WARING LIGHT
(1) Disconnect the connector from the park brake switch.
(2) Turn the ignition ON, the park brake warning light should go out.
(3) Short connector terminal to the ground with a wire, the park brake warning light should light up.Standa rd indic ation Re sista nc e (Ω)
C159.5—169.5
1/2H
53—59
Warning point 26.7—30.7
H 20—24
304Section 4 Service Caution & NoticeI. Service CautionRefrigerant Treatment
•During the treatment, the operator shall be careful not to inhale A/C refrigerant or lubricant vapor. Long-
term exposure to the A/C environment will cause the operator's eye, nose and throat liable to stimulation.
In addition, based on the consideration on the environment influence, when discharging the HFC-134a
from the A/C system, we suggest using the recyclable and rechargeable devices. If sudden system fault
occurs, it is recommended to place the device on a ventilated place before starting service.
•For HFC-134a service equipment, it is recommended not to perform the pressurization check or leakage
inspection. If these mixture combust, it may result in severe human injury or property loss.
•Please be noticed not to let the refrigerant leak near the spark or other hot objects. If the refrigerant gas
contacts the spark or similar heat source (e.g. cigarette or heater), it may generate poisonous gas. The
refrigerant is extremely liable to leakage during the transportation. In this case, please eliminate or remove
the heat source mentioned above and keep good ventilation.
•It is very dangerous to handle the liquid refrigerant. Only a drop of refrigerant can result in local frostbite
on skin if dropped on the skin of the operator. Therefore, it is specified that the operator shall always
wear glove and eye protection during the handling of the liquid refrigerant. If liquid refrigerant gets in
your eyes or on your skin, Wash the area with much cool water. Go immediately to hospital for professional
treatment.
Refrigerant Preservation
• Refrigerant preservation container is a high pressure resistant equipment. If it is put in hot treatment, the
explosion may arise, and the resulting metal fragments and the splashed liquid refrigerant will result in
severe human injury. It is recommended to preserve the refrigerant below 40°C.II. Service NoticeInsufficient Refrigerant Handling
•If the refrigerant is founded to be insufficient during the fault diagnosis, it is recommended not to add
refrigerant because of the following facts: the pressure readings indicated by different pressure gauge
are different, thus you will be unable to determine the exact amount of the refrigerant to be added, and
excessive or insufficient refrigerant may cause a series of chained negative effects such as damaged
refrigerant circulation parts or deteriorated refrigeration effect. Therefore, if the refrigerant is found to
be insufficient, it is recommended to drain the refrigerant from the refrigerant circulation pipeline and fill
specified amount of the refrigerant.
Compressor Oil Handling
•For this type of vehicle, it is recommended to use SW-100 type compressor oil. Use of PAG compressor
oil other than the SW-100 type may cause the A/C compressor to be damaged.
•During the operation, please be noticed not to splash the SW-100 type compressor oil onto the vehicle
surface. Therefore, if this happens, please wipe it off immediately, otherwise the compressor oil will
damage the paint on the vehicle surface.
305•Compared with the early used mineral oil, the SW-100 type compressor oil is of comparatively high
moisture absorption performance. If you mix the moisture object with the SW-100 type compressor oil, it
will damage the Refrigeration system. Therefore, after treating the compressor oil or removing the
refrigeration system components, the lid shall be covered immediately to prevent the SW-100 type
compressor oil from absorbing the moisture.Section 5 The Refrigeration System Operation ProcedureI. Refill RefrigerantNotice:•During the filling of refrigerant into the refrigeration system, be careful that it is required to
have the professionals operate under the specified standard and procedure, otherwise it will
reduce the A/C efficiency greatly and even damage the refrigeration system components.
Refill the HFC-134a refrigerant
Refill Preparation1. Install the inflating equipment.
2. Connect the low pressure tube to the low pressure
refill valve.
3. Connect the high pressure tube to the high pressure
refill valve.
4. Connect the intermediate tube to the vacuum pump.Vacuumization:1. Open all valves.Notice:•Close all valves of the manifold gauge immediately after the vacuum pump stops operation. If
the valve is still open after the vacuum pump stops operation, then the vacuum pump oil will
return to refrigerant circulation loop and reduce the A/C efficiency.2. Start the vacuum pump and run it for 15min.
3. Check if the readings at high and low sides of the manifold gauge fall within the range of -101 kPa{-760
mmHg }. Close the valves of the manifold gauge.Check the air tightness:1. Stop the vacuum pump and have it wait for 5min.
2. Check the high pressure side of the manifold gauge and the reading at the low pressure side.
•Check for leakage if the reading changes and vacuumize it again.
•Refill the new HRC-134a refrigerant if the reading doesn't change.To low pressure fill valveLow Pressure GaugeHigh Pressure
GaugeConnect the high
pressure refill valveLow Pressure TubeHigh Pressure TubeLow Pressure
Manual ValveHigh Pressure
Manual ValveVacuum PumpIntermediate Tube
Refrigerant Steel Jar
311Check the condenser1. Check for crack, damage or oil leakage.
•Replace the condenser if any of the above-mentioned faults occurs.
2. Check if the fin area is blocked by dust.
•Clean it if it is blocked.
3. Check if the fin area bends.
•If the fin area bends, level it with a flat head screwdriver.6. Refrigeration Pipeline Removal / Installation1. Remove battery.
2. Drain the refrigerant from the system.
3. Remove air filter.
4. Remove the clamp.
5. Remove the compressor inlet hose.
6. Remove the compressor outlet hose.
7. Remove liquid pipe I.
8. Remove pressure switch connector.
9. Remove the pipe clamp.
10. Remove liquid pipe II.
11. The installation is in the reverse order of the removal.Notice:•If anything moisture or any foreign matter enters into the Refrigeration system for circulation,
the cooling performance of the Refrigeration system will obviously deteriorate with abnormal
noise. Plug the port immediately after removing any cooling circulation component to prevent
anything moistur or any foreign matter from entering the circulation.
Introduction Of The Refrigeration Pipeline Removal:
Nuts union type:Loose the nuts with 2 wrenches and then remove the refrigeration pipe (or the hose).Slider joint type:Clip the slider block recess end with pliers or the similar tool and remove the attaching bolt or screw cap.
313Section 7 A/C System Faults Check & TroubleshootingI. A/C System Faults CheckInspection shall be made to isolate the fault area and its cause when the fault of A/C system occurs, and then
specific service could be performed. Inspect the whole system before re-using A/C system after a long term
of storage.
First step is initial inspection by direct "see, listen and touch". Test the system with the leak detector if
necessary.
1. Check the Refrigeration System
Under the normal condition, the low pressure pipeline of the A/C refrigeration system takes on a status of lowtemperature and the high pressure pipeline takes on a status of high temperature, see Figure 16. Based onthis rule, you can arrive at the initial judgement about the fault area and its cause by touching the refrigeration
system pipeline and elements to feel the surface temperature with your hand.
1High pressure area: compressor outlet
condenser receiver/drier expansion valve
inlet, its temperature change trend is from warm
to hot. If the temperature change is not this trend,
but instead some part is extremely hot (e.g.
condenser surface), it indcates that the part is
faulty and the radiation is not good; if some part is
extremely cold (e.g. receiver/drier) or there is frost
(e.g. at expansion valve inlet), it indicates that the
part is faulty and the pipe may be blocked.
2Low pressure area: expansion valve outlet
evaporator compressor inlet, its temperature
change trend is from cool to cold, If the
temperature change is not this trend, it indcates that the part is faulty.
3Compressor: compressor inlet and outlet high & low side shall have apparent feel of temperature difference,
if there is no temperature difference, it indicates that there is leakage in the system and the refrigerant
has leaked.
2. Check the Leakage Area
1Observe all connecting areas of the refrigeration system or condenser surface for oil stain, if there is oil
stain, it indicates that the the refrigerant is leaking (refrigerant and freezing oil leak simultaneously,
refrigerant volatilize after leakage and leave the freezing oil remained to be oil stain).
2Apply the soap water to the connecting area, if soap bubble occurs, it indicates that there is leakage.
3Check with instrument, the common instrument is halogen leak detector. When using the halogen leak
detector for check, the key is the propane flame color depending on which the judgement is made. When
there is no leakage, the flame color remains unchanged, when there is a little leakage, the flame is
greenish, when there is large leakage, the flame is bluish or purple.CoolColdHotWarmExpension
Va l v eCompressorEvaporator Condenser Gas
GasLiquid LiquidLow PressureHigh PressureFigure 16 A/C System Process → →
→→
315II. A/C System Diagnosis and TroubleshootingTable 1 Abnormal high pressure of the high pressure pipelineAbnormal low pressure of the high pressure pipeline Abnormal high pressure of the low pressure pipelineAbnormal low pressure of the low pressure pipelineHigh and low pressure can not be establishedSight glass has air bubble Compressor inlet side is frosted Compressor noise Abnormal heating on the compressorEvaporator is frostedDrier filter ices up A/C does not refrigerate or the cold air is insufficient× × × × Excessive refill of refrigerantDrain p rop er amount of
refrigerant
× × × × T oo lit t le refill of refrigerantRep air t he gas leak area, refill
p rop er amount of refrigerant
× × × × Refrigerant is leaked allRep air t he gas leak area, refill
p rop er amount of refrigerant
×× ××× ×T here is non-clot t ed gas in
the sy stemLoos en receiver and
condenser inlet connect or,
discharge t he non-clot t ed gas
××Excessive freez ing oil in t he
sy stemCheck comp ressor freez ing
oil level, adjus t it
× Excessive high t emp erat ure
of condenser inletPerform t he check at t he
p lace w it h good vent ilat ion
T here is dus t in t he
condens er core, air channel
w it hin t he condens er is
blocked or suffocat edU s e comp res s ed air or w at er
t o flush and remove t he dirt
on t he condenser
Condenser fan faulty or
brokenCheck the wiring status and
t he fan mot or, correct or
rep lace it
×× Exces s ively low t emp erat ure
of condenser inletStop the op eration of the
refrigerat ion sy st em
× × × Drier blocked Clean
A ir channel in t he evap orat or
blocked or suffocat edRemove t he dirt on t he
evap orat or
Evap orat or fan fault , p oor
blower mot or w ire connect ionCheck the wiring status and
t he fan mot or, correct or
rep lace it
×× ×T here is dirt in evap orat or
coreU s e t he comp res s ed air t o
clean t he evap orat or core × ×
××××
× P roblem Sy mp t om
Possible Cause T roubleshoot ing
×