NO.10 AIR FROM VENT NOT COLD ENOUGH

BME070300000W12

10

Air from vent not cold enough

DESCRIPTION

• Magnetic clutch operates but A/C system malfunctions.

POSSIBLE CAUSE

• Drive belt malfunction
• Malfunction in blower unit, rear A/C unit and/or condenser
• Malfunction in RECEIVER/DRIER or expansion valve (valve closes too much)
• Malfunction in refrigerant lines
• Malfunction in piping connections
• A/C compressor system malfunction, insufficient compressor oil
• Compressor oil over-full, malfunction in expansion valve or front and/or rear A/C unit air mix link system

Diagnostic procedure

STEP

INSPECTION

ACTION

1
INSPECT DRIVE BELT
• Inspect drive belt.
- L3:
(See DRIVE BELT INSPECTION [L3])
- MZR-CD (RF Turbo):
(See DRIVE BELT INSPECTION [MZR-CD (RF Turbo)])
• Is it okay?
Yes
Go to next step.
No
Replace drive belt, then go to Step 19.
2
INSPECT REFRIGERANT SYSTEM PERFORMANCE
• Carry out refrigerant system performance test.
• Is operation normal?
Yes
Operation is normal. (Recheck malfunction symptoms.)
No
Go to next step.
3
VERIFY WHETHER MALFUNCTION IS IN A/C UNIT INTAKE AND CONDENSER OR ELSEWHERE
• Are refrigerant's high-pressure and low-pressure values both high?
Yes
Go to next step.
No
Go to Step 6.
4
INSPECT FRONT AND/OR REAR A/C UNIT INTAKE
• Are front and/or rear A/C unit intake clogged?
Yes
Remove obstruction, then go to Step 19. (If air does not reach evaporator within front and/or rear A/C unit, heat exchange does not occur and refrigerant pressure rises. Therefore, removal of obstruction is necessary.)
No
Go to next step.
5
INSPECT CONDENSER
• Inspect condenser.
• Is it okay?
Yes
Add or subtract refrigerant to make specified amount, then go to Step 19. (Excessive amount of refrigerant.)
No
Replace condenser, or repair and clean condenser fins, then go to Step 19.
6
VERIFY WHETHER MALFUNCTION IS IN EXPANSION VALVE, RECEIVER/DRIER AND REFRIGERANT LINES OR ELSEWHERE
• Are refrigerant's high-pressure and low-pressure values low?
Yes
Go to next step.
No
Go to Step 13.
7
VERIFY WHETHER MALFUNCTION IS IN EXPANSION VALVE AND RECEIVER/DRIER OR ELSEWHERE
• Immediately after A/C compressor operates, does refrigerant's high-pressure value momentarily rise to correct value, then fall and stay below it? (Is there negative pressure on low-pressure side?)
Yes
Go to next step.
No
Go to Step 9.
8
VERIFY WHETHER MALFUNCTION IS IN EXPANSION VALVE OR RECEIVER/DRIER
• Turn A/C switch off and let air conditioner stop for 10 minutes.
• Start engine.
• Turn both A/C switch and front fan switch on.
• Does malfunction occur after A/C compressor turns on?
Yes
Replace expansion valve, then go to Step 19. (Since valve closes too much, replacement is necessary.)
No
Start vacuum pump for 30 minutes and replace condenser, then go to Step 19. (Since RECEIVER/DRIER has become saturated with water, replacement is necessary.)
9
INSPECT REFRIGERANT LINES
• Inspect refrigerant lines as follows.
- Is piping free of damage and cracks?
- Are piping connections free of oil grime? (Visual inspection)
- Are piping connections free of gas leakage?
- Are piping installation points on condenser free of gas leakage?
- Are piping installation points on A/C compressor free of gas leakage?
- Are piping installation points on rear A/C unit free of gas leakage?
- Perform gas leak inspection using gas leak tester.
• Are above items okay?
Yes
Go to next step.
No
If piping or an A/C component is damaged or cracked, replace it. Then go to Step 19.
If there is no damage, go to Step 12.
10
INSPECT EVAPORATOR PIPING CONNECTIONS IN A/C UNIT FOR GAS LEAKAGE
• Are piping connections for front and/or rear evaporator in rear A/C unit free of gas leakage?
Yes
If the A/C compressor is making noise, add 10 ml {10 cc, 0.338 fl oz} of compressor oil and verify that malfunction does not occur.
Add or subtract refrigerant to make specified amount, then go to Step 19.
No
If piping is damaged or cracked, replace it. Then go to Step 19.
If there is no damage, go to next step.
11
INSPECT EVAPORATOR PIPING CONNECTIONS IN A/C UNIT FOR LOOSE
• Are piping connections for front and/or rear evaporator in rear A/C unit loose?
Yes
Tighten connections to specified torque. If the A/C compressor is making noise, add 10 ml {10 cc, 0.338 fl oz} of compressor oil and verify that malfunction does not occur.
Add or subtract refrigerant to make specified amount, then go to Step 19.
No
If the A/C compressor is making noise, add 10 ml {10 cc, 0.338 fl oz} of compressor oil and verify that malfunction does not occur.
Replace O-ring on piping, add or subtract refrigerant to make specified amount, then go to Step 19.
12
INSPECT PIPING CONNECTIONS FOR LOOSE
• Are piping connections loose?
Yes
Tighten connections to specified torque. If the A/C compressor is making noise, add 10 ml {10 cc, 0.338 fl oz} of compressor oil and verify that malfunction does not occur.
Add or subtract refrigerant to make specified amount, then go to Step 19.
No
If the A/C compressor is making noise, add 10 ml {10 cc, 0.338 fl oz} of compressor oil and verify that malfunction does not occur.
Replace O-ring on piping, add or subtract refrigerant to make specified amount, then go to Step 19.
13
VERIFY WHETHER MALFUNCTION IS IN EXPANSION VALVE, AIR MIX ACTUATOR AND COMPRESSOR OIL OR ELSEWHERE
• Does refrigerant's high-pressure value hardly increase?
Yes
Go to next step. (Pressure hardly increases.)
No
Go to Step 16.
14
VERIFY WHETHER MALFUNCTION IS IN COMPRESSOR OIL AMOUNT AND A/C COMPRESSOR OR ELSEWHERE
• When engine is racing, does high-pressure value increase?
Yes
Return to Step 3.
No
Go to next step.
15
VERIFY WHETHER MALFUNCTION IS IN COMPRESSOR OIL AMOUNT OR A/C COMPRESSOR
• After compressor oil is replenished each 10 ml {10 cc, 0.338 fl oz}, does high-pressure value increase?
Yes
Troubleshooting completed. (Explain to customer that cause was insufficient compressor oil.)
No
Replace A/C compressor, then go to Step 19. (Cause is defective A/C compressor.)
16
VERIFY WHETHER MALFUNCTION IS IN EXPANSION VALVE OR ELSEWHERE
• Is only refrigerant low-pressure value high?
Yes
Replace expansion valve, then go to Step 19. (Since valve opens too much, replacement is necessary.)
No
Go to next step.
17
VERIFY THAT AIR MIX ACTUATOR IS INSTALLED SECURELY AND PROPERLY
• Are front and/or rear A/C unit's air mix link, crank, and shaft securely and properly installed?
Yes
Go to next step.
No
Repair or install link, crank, and shaft securely in proper position, then go to Step 19.
18
ADJUST COMPRESSOR OIL
• Set the front fan switch at 4th position.
• Turn the A/C switch on.
• Set in FRESH mode.
• Set the temperature control to MAX COLD.
• Set in VENT mode.
• Run engine at a constant 1,500 rpm for 10 minutes.
• Run engine at idle speed for 1 minute.
1 engine speed cycle is defined as going from idle speed to 4,000 rpm and back to idle speed over a period of 12 seconds. Perform 5 cycles.
• Run engine at idle speed for 30 seconds.
• Remove all compressor oil from A/C compressor and verify that it is 100 ml {100 cc, 3.38 fl oz}.
• If it is more than 100 ml {100 cc, 3.38 fl oz}, put only 100 ml {100 cc, 3.38 fl oz} back into A/C compressor.
• Carry out above Steps 1 to 10 again and verify that compressor oil is 100 ml {100 cc, 3.38 fl oz}.
• Is there 100 ml {100 cc, 3.38 fl oz} of compressor oil in A/C compressor?
Yes
Go to next step.
No
Follow Steps 1 to 10 again until compressor oil is 100 ml {100 cc, 3.38 fl oz}.
19
VERIFY THAT MALFUNCTION SYMPTOM OCCURS AFTER REPAIR
• Does cool air blow out? (Are results of refrigerant system performance test okay?)
Yes
Troubleshooting completed. Explain repairs to customer.
No
Recheck malfunction symptoms, then repeat from Step 1 if malfunction recurs.