Vacuum occurs on low pressure side, and
pressure on high pressure side is too low,
frost exists on lines on both sides of
condenser or expansion valve

Moisture in refrigerant (excessive)

Expansion valve (dirty or blocked)

31-80

A/C line (leaked)

31-94

Condenser (dirty or blocked)

31-102

Pressure is too high on both low and high
pressure sides

Expansion valve (faulty)

Refrigerant oil (excessive)

31-68

Symptom

Suspected Area

See page

31–

Diagnosis Procedure

HINT:
Use the following procedures to troubleshoot the A/C system.

Standard voltage: 11 to 14 V
If voltage is below 11 V, recharge or replace the battery before proceeding to next step.

a. Check each actuator and sensor code (

See page 31-19

 Indicator inspection
 Sensor inspection

Pressure on low pressure side is normal or
slightly low, and pressure on high pressure
side is too high

Surface of condenser (dirty)

31-102

Cooling fan (not operating)

Refrigerant (overcharged)

31-66

Air in refrigerant

31-67

Engine (overheating)

Pressure on low pressure side is too high,
and pressure on high pressure side is too
low

Compressor assembly belt (slip)

31-99

Compressor assembly (faulty)

31-99

Pressure on low pressure side is too low,
and pressure on high pressure side is too
high

A/C high pressure line (blocked)

31-96

Expansion valve (faulty)

Vehicle brought to workshop

Check battery voltage

Customer problem analysis

Check panel diagnosis

Symptom

Suspected Area

See page

NEXT

31–

a. On-vehicle inspection
b. Inspection

Check and clear DTCs, then read DTCs again

For current DTC, go to step 7

For history DTC, go to step 8

DTC
occurs



DTC

Overall analysis and troubleshooting

Troubleshoot according to Diagnostic Trouble Code (DTC) chart, then go to step 9

Troubleshoot according to Problem Symptoms Table, then go to step 9

Confirm troubleshooting and perform test

End

NEXT

31–

A/C System Function

1. Self-checking Operation

a. Turn ignition switch ON.
b. Press the A/C + rear defogger button on A/C control panel for 10 seconds and A/C begins



self-checking. The self-checking takes about 15 seconds, during which the A/C cannot work.

HINT:
If it is unable to determine whether A/C has begun self-checking, turn on the blower before performing



self-checking and push the A/C + rear defogger button. If no air comes out, it indicates A/C is performing
self-checking.

2. Self-diagnosis Function

a. Electrical A/C

Self-diagnosis operation: Press the A/C + outer circulation button for more than 5 seconds.
Malfunction display: Malfunction is indicated by flashing indicator. A/C indicator flash indicates the ten
digit and rear defogger indicator flash indicates the single digit. The interval of flashes for ten digit and
single digit is 0.5 seconds, and the interval of flashes between ten digit and single digit is 2 seconds. If
there are more than one malfunctions, the ten digit and single digit indicators will display (as the first
DTC) again 5 seconds after the single digit indicator turns off. The ten digit and single digit indicators
remain on for 3 seconds at the same time after the single digit indicator goes off for 2 seconds, which
indicates self-diagnosis is completed and it has exited the system (power on or turn on/off A/C
controller can both force the diagnosis function to end). System enters the state before diagnosis after
exiting self-diagnosis mode.
Detail correspondence of codes and malfunction is as follows:

Code

Content

Code

Content

No malfunction, system operates
properly

Circulation damper motor
malfunction (invalid adjustment)

Reserve

Mode damper motor malfunction
(invalid adjustment)

Reserve

Mix damper motor malfunction
(invalid adjustment)

Reserve

Evaporator temperature sensor
malfunction (short or open)

Reserve

Communication with BCM
malfunction

Blower malfunction (invalid
adjustment)

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