Mitsubishi Galant (2004+). Manual - part 772

MANUAL A/C DIAGNOSIS

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HEATER, AIR CONDITIONING AND VENTILATION

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STEP 2. Using scan tool MB991958, check data list item 04: 
A/C pressure sensor.

CAUTION

To prevent damage to scan tool MB991958, always turn the 
ignition switch to the "LOCK" (OFF) position before con-
necting or disconnecting scan tool MB991958.
(1) Connect scan tool MB991958 to the data link connector.
(2) Assemble a manifold gauge onto the high pressure service 

valve.

(3) Turn ON the engine and then turn ON the air conditioner 

switch.

(4) Set scan tool MB991958 to the data reading mode for item 

04: A/C pressure sensor.

• Check that the refrigerant pressure matches the dis-

played value on the scan tool.

(5) Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is the sensor within the specified range?

YES : Go to Step 7.
NO :  Go to Step 3.

AC305412

AB

MB991910

DATA LINK

CONNECTOR

MB991824

MB991827

MANUAL A/C DIAGNOSIS

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HEATER, AIR CONDITIONING AND VENTILATION

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STEP 3. Check A/C pressure sensor connector A-30 for 
loose, corroded or damaged terminals, or terminals 
pushed back in the connector.

Q: Is A/C pressure sensor connector A-30 in good 

condition?
YES : Go to Step 4.
NO :  Repair or replace the connector. Refer to GROUP 

00E, Harness Connector Inspection 

P.00E-2

. Check 

that the air conditioning works normally. 

AC305206

CONNECTOR: A-30

AY

HARNESS SIDE

A-30 (B)

AC305234

CONNECTORS: C-15, C-16

C-16 (B)

HARNESS SIDE

C-16

C-15

C-15 (B)

HARNESS SIDE

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MANUAL A/C DIAGNOSIS

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HEATER, AIR CONDITIONING AND VENTILATION

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STEP 4. Check the A/C pressure sensor.

1. Assemble a gauge manifold on the high pressure service 

valve.

2. Disconnect the A/C pressure sensor connector and connect 

special tool test harness MB991658 as shown in the illustra-
tion.

3. Turn ON the engine and then turn ON the air conditioner 

switch.

4. At this time, check to see that the voltage of A/C pressure 

sensor terminal No. 2 reflects the specifications of the fig-
ure.
NOTE: The allowance shall be defined as 

±

5%.

Q: Is the A/C pressure sensor in good condition?

YES : Go to Step 5.
NO :  Replace the A/C pressure sensor. Check that the air 

conditioning works normally. 

AC305034

A/C PRESSURE SENSOR

AD

AC307368

A/C 
PRESSURE 
SENSOR 
SIDE

MB991658

AB

HARNESS SIDE

AC208297AB

REFRIGERANT PRESSURE (MPa)

OUTPUT VOLTAGE 

(V)

0

1

2

3

5

4

1

2

3

MANUAL A/C DIAGNOSIS

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HEATER, AIR CONDITIONING AND VENTILATION

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STEP 5. Check A/C-ECU C-15 and C-16 for loose, corroded 
or damaged terminals, or terminals pushed back in the 
connector.

Q: Are A/C-ECU C-15 and C-16 in good condition?

YES : Go to Step 6.
NO :  Repair or replace the connector. Refer to GROUP 

00E, Harness Connector Inspection 

P.00E-2

. Check 

that the air conditioning works normally. 

AC305206

CONNECTOR: A-30

AY

HARNESS SIDE

A-30 (B)

AC305234

CONNECTORS: C-15, C-16

C-16 (B)

HARNESS SIDE

C-16

C-15

C-15 (B)

HARNESS SIDE

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