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NO.10 AIR FROM VENT NOT COLD ENOUGH

BME070301038212

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.

  - AJ:
  (See DRIVE BELT INSPECTION [AJ])
  - 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.