NO.8 AIR FROM FRONT/REAR VENTS NOT COLD ENOUGH

id070300901200

8
Air from front/rear vents not cold enough
DESCRIPTION
•  Magnetic clutch operates but A/C system malfunctions
POSSIBLE CAUSE
Note
•  If the engine coolant temperature increases due to a cooling system malfunction, the fail-safe function disables the A/C operation.
•  Drive belt malfunction
•  Refrigerant pressure switch malfunction (PCM type A)
•  Refrigerant pressure sensor malfunction (PCM type B)
•  Cooling fan system malfunction
•  Condenser or related part malfunction
•  A/C unit or condenser malfunction
•  Receiver/drier or expansion valve malfunction (valve closes too much)
•  Malfunction in refrigerant lines
•  A/C compressor system malfunction, insufficient compressor oil
•  Over filling of compressor oil, malfunction in expansion valve or A/C unit air mix link system
•  Evaporative temperature sensor malfunction

Diagnostic procedure

STEP

INSPECTION

ACTION
1
INSPECT CLIMATE CONTROL UNIT FOR DTC
•  Retrieve the climate control unit DTC using the A/C Operation Check Mode.
•  Are there DTC displayed?
Yes
Go to the applicable DTC troubleshooting procedures.
(See DIAGNOSTIC TROUBLE CODE NUMBER INSPECTION.)
No
Go to the next step.
2
INSPECT REFRIGERANT PRESSURE TO LOCATE MALFUNCTION
•  Perform refrigerant pressure check.
•  Is the refrigerant pressure normal?
Yes
Go to the next step.
No
Record the inspection result.
•  If the refrigerant high-pressure and low-pressure values are both high, go to Step 8.
•  If the refrigerant high-pressure and low-pressure values are approximately the same, go to Step 11.
•  If the refrigerant high-pressure and low-pressure values are both low, go to Step 13.
•  If there is a vacuum on the low pressure side and extremely low pressure on the high pressure side, go to Step 19.
•  If there is low pressure on the high pressure side and high pressure on the low pressure side, replace the A/C compressor, then go to Step 23.
•  If the refrigerant pressure is other than above condition, go to Step 21.
3
INSPECT REFRIGERANT SYSTEM PERFORMANCE
•  Perform the refrigerant system performance test on the front or rear A/C from the side which cool air does not blow.
•  Is the operation normal?
Yes
Operation is normal (Recheck malfunction symptoms.).
No
Go to the next step.
4
INSPECT DRIVE BELT
•  Inspect the drive belt.
•  Is it normal?
Yes
Go to the next step (PCM type B).
Go to Step 6 (PCM type A).
No
Adjust or replace the drive belt, then the next step.
(See DRIVE BELT REMOVAL/INSTALLATION [MZI-3.7].)
5
INSPECT REFRIGERANT PRESSURE SENSOR
•  Inspect the refrigerant pressure sensor.
(See REFRIGERANT PRESSURE SENSOR INSPECTION.)
•  Is it normal?
Yes
Go to Step 8.
No
Repair or replace malfunctioning part according to inspection result, then go to Step 23.
6
INSPECT REFRIGERANT PRESSURE SWITCH
•  Inspect the refrigerant pressure switch.
(See REFRIGERANT PRESSURE SWITCH INSPECTION.)
•  Is it normal?
Yes
Go to the next step.
No
Replace the refrigerant pressure switch, then go to Step 23.
(See REFRIGERANT PRESSURE SWITCH REMOVAL/INSTALLATION.)
7
INSPECT REFRIGERANT PRESSURE SWITCH RELATED HARNESS
•  Inspect following refrigerant pressure switch wiring harness (open or short circuit) and connectors (corrosion, pulled out pins).
―  PCM terminal 1B and refrigerant pressure switch terminal C
―  PCM terminal 1R and refrigerant pressure switch terminal D
―  Climate control unit terminal 1Q and refrigerant pressure switch terminal B
―  Refrigerant pressure switch terminal A and ground
•  Is it normal?
Yes
Go to the next step.
No
Repair or replace malfunctioning part according to inspection result, then go to Step 23.
8
INSPECT COOLING FAN OPERATION
•  Verify the cooling fan operation.
•  Is the cooling fan operation normal?
Yes
Go to the next step.
No
Repair or replace the malfunctioning location according to the inspection results.
Then go to Step 23.
9
VISUALLY INSPECT CONDENSER
•  Is the condenser fin clogged or obstructed by foreign material?
Yes
Remove the foreign material.
Repair the condenser fin.
Then go to Step 23.
No
Go to the next step.
10
CHECK REFRIGERATION SYSTEM FOR OVERCHARGE OR AIR CONTAMINATION
•  Is the low side line hot to the touch?
Yes
Recover refrigerant. Evacuate system for one hour. Refill with correct amount of refrigerant, and go to step 23.
No
Recover refrigerant, evacuate for 15 minutes, refill with correct amount and go to step 23.
11
CHECK TO SEE WHETHER MALFUNCTION IS IN EXPANSION VALVE OR ELSEWHERE
•  Compare the refrigerant pressure of the low pressure side with the high pressure side at Step 2.
•  Is there little difference between the high pressure side and low pressure side readings (refer to graph in REFRIGERANT PRESSURE CHECK procedure)?
Yes
Replace the expansion valve.
After performing the following servicing, go to Step 23.
•  Adjust the compressor oil to the specified level.
•  After discharging, charge with new refrigerant to the specified level.
No
Go to the next step.
12
INSPECT AIR MIX DOOR RELATED PART INSTALLATION
•  Measure the climate control unit terminal 2F and 2G voltage when the temperature control dials are set to MAX COLD and MAX HOT by control panel.
•  Are voltages normal?
Yes
Adjust the compressor oil to the specified amount, then go to Step 23.
(See A/C COMPRESSOR REMOVAL/INSTALLATION.)
No
•  Inspect the air mix link, air mix crank, and air mix rod of the A/C unit correctly and securely installed to their positions.
•  Repair or install correctly for suspect part according to inspection result, then go to next Step.
13
INSPECT BLOWER UNIT FOR BLOCKAGE
•  Is the blower unit intake and air filter of the front or rear A/C from the side which cool air does not blow clogged?
Yes
Remove the cause of the clogging. Replace the air filter if it is clogged.
(See AIR FILTER REMOVAL/INSTALLATION.)
Then go to Step 23.
No
Go to the next step.
14
CHECK TO SEE WHETHER MALFUNCTION IS REFRIGERANT LINE LEAKAGE OR ELSEWHERE
•  Verify if there is gas leakage from the system hoses using the gas leak tester.
•  Is there gas leakage?
Yes
If there is leakage from a system hose connection area, go to Step 16.
If there is leakage other than from a system hose connection area, go to Step 18.
No
Go to the next step.
15
VISUALLY INSPECT REFRIGERANT LINE
•  Is a system hose crushed?
Yes
Replace the crushed system hose.
(See REFRIGERANT LINE REMOVAL/INSTALLATION.)
After performing the following servicing, go to Step 23.
•  Adjust the compressor oil to the specified level.
•  After discharging, charge with new refrigerant to the specified level.
No
Go to Step 22.
16
CHECK TO SEE WHETHER MALFUNCTION IS IN REFRIGERANT LINE JOINT LOOSE OR O-RING
•  Tighten the system hose connection area to the specified torque.
•  Has the leakage stopped?
Yes
Go to the next step.
No
Go to Step 18.
17
VISUALLY INSPECT REFRIGERANT LINE
•  Is a system hose crushed?
Yes
Replace the crushed system hose.
(See REFRIGERANT LINE REMOVAL/INSTALLATION.)
After performing the following servicing, go to Step 23.
•  Adjust the compressor oil to the specified level.
•  After discharging, charge with new refrigerant to the specified level.
No
Adjust the compressor oil to the specified amount, then go to Step 23.
(See A/C COMPRESSOR REMOVAL/INSTALLATION.)
18
VISUALLY INSPECT REFRIGERANT LINE
•  Is a system hose crushed?
Yes
Replace the O-ring of the leaking area.
Replace the crushed system hose.
(See REFRIGERANT LINE REMOVAL/INSTALLATION.)
After performing the following servicing, go to Step 23.
•  Adjust the compressor oil to the specified level.
•  After discharging, charge with new refrigerant to the specified level.
No
Replace the O-ring of the leaking area.
After performing the following servicing, go to Step 23.
•  Adjust the compressor oil to the specified level.
•  After discharging, charge with new refrigerant to the specified level.
19
CHECK TO SEE WHETHER MALFUNCTION IS WATER IN REFRIGERANT SYSTEM OR ELSEWHERE
•  Does the refrigerant pressure on the low pressure side vary between the vacuum and normal range?
Yes
Replace the condenser.
(Water in refrigerant system)
(See CONDENSER REMOVAL/INSTALLATION.)
Then go to Step 23.
No
Go to the next step.
20
CHECK TO SEE WHETHER MALFUNCTION IS IN RECEIVER DRYER FILTER OR EXPANSION VALVE
•  Remove the expansion valve of the front or rear A/C from the side which cool air does not blow and verify its condition.
•  Is there refrigerant leakage or valve clogging?
Yes
If there is foreign matter clogging the valve:
•  Remove the foreign matter.
If there is refrigerant leakage or clogging:
•  Replace the expansion valve.
Perform discharge, charge with new refrigerant, and then go to Step 23.
No
Replace the condenser (Receiver/Dryer filter is clogged.).
(See CONDENSER REMOVAL/INSTALLATION.)
Then go to Step 23.
21
INSPECT EVAPORATIVE TEMPERATURE SENSOR
•  Inspect the evaporator temperature sensor of the front or rear A/C from the side which cool air does not blow.
•  Is it normal?
Yes
Verify the evaporator temperature sensor position.
(See FRONT A/C UNIT DISASSEMBLY/ASSEMBLY.)
(See REAR A/C UNIT DISASSEMBLY/ASSEMBLY.)
Then go to Step 23.
No
Replace the evaporator temperature sensor, then go to Step 23.
(See FRONT A/C UNIT DISASSEMBLY/ASSEMBLY.)
(See REAR A/C UNIT DISASSEMBLY/ASSEMBLY.)
22
INSPECT AIR MIX DOOR RELATED PART INSTALLATION
•  Measure the climate control unit terminal 2F and 2G voltage when the temperature control dials are set to MAX COLD and MAX HOT by control panel.
•  Are voltages are normal?
Yes
Go to the next step.
No
•  Inspect the air mix link, air mix crank, and air mix rod of the A/C unit correctly and securely installed to their positions.
•  Repair or install correctly for suspect part according to inspection result, then go to next Step.
23
VERIFY THAT MALFUNCTION SYMPTOM DOES NOT OCCURS AFTER REPAIR
•  If the refrigerant discharged during inspection has not been recharged, discharge and charge with new refrigerant to the specified level.
•  Does cool air blow out? (Are results of refrigerant system performance test normal?)
Yes
Troubleshooting completed. Explain repairs to customer.
No
Recheck malfunction symptoms, then repeat from Step 1 if malfunction recurs.