Mitsubishi Eclipse / Eclipse Spyder (2000-2002). Service and repair manual — part 692

MANUAL A/C DIAGNOSIS

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HEATING AND AIR CONDITIONING

55-5

MANUAL A/C DIAGNOSTIC TROUBLESHOOTING STRATEGY

M1552009600085

Use these steps to plan your diagnostic strategy. If
you follow them carefully, you will be sure that you
have exhausted most of the possible ways to find a
heater, air conditioning and ventilation fault.
1. Gather information from the customer.

2. Verify that the condition described by the

customer exists.

3. Find the malfunction by following the Symptom

Chart.

4. Verify malfunction is eliminated.

SYMPTOM CHART

M1552009900075

NOTE: For symptoms marked with an asterisk the
condenser fan might not operate when there is an air
conditioning low load from the air conditioning
condenser control, so remove the battery terminal (-)
and then check the symptoms after 5 minutes since
initial start control after reconnection.

SYMPTOM PROCEDURES

INSPECTION PROCEDURE 1: When the ignition switch is "ON," the A/C does not operate.

DIAGNOSIS

STEP 1. Check for refrigerant leaks.

Q: Is the refrigerant leaking?

YES : Repair the leak. Then go to Step 11.
NO : Go to Step 2.

STEP 2. Check for excessive refrigerant.

Q: Is the refrigerant in good condition?

YES : Go to Step 3.
NO : Use the refrigerant recovery station to remove all of

the refrigerant, and then calculate the amount of the
refrigerant and charge it. Then go to Step 11.

SYMPTOMS

INSPECTION
PROCEDURE

REFERENCE
PAGE

When the ignition switch is "ON," the A/C does not operate.

1.

P.55-5

When the air outlet changeover control knob is moved to DEFROSTER or
DEFROSTER/FOOT position, the A/C or the inside/outside air
changeover damper motor does not operate.

2.

P.55-9

When the A/C is operating, temperature inside the passenger
compartment does not decrease (cool air is not emitted).

3.

P.55-9

Blower fan and motor does not turn.

4.

P.55-11

Blower fan and motor does not stop turning.

5.

P.55-13

When the A/C is operating condenser fan or radiator fan does not turn.*

6.

P.55-15

The A/C indicator flashes <vehicles with 3.0L engine>.

7.

P.55-16

MANUAL A/C DIAGNOSIS

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HEATING AND AIR CONDITIONING

55-6

STEP 3. Check the A/C compressor relay continuity.

Q: Is the A/C compressor relay in good condition?

YES : Go to Step 4.
NO : Replace. Then go to Step 11.

STEP 4. Check the magnetic clutch operation.
Connect the battery (+) terminal to the compressor magnetic
clutch connector terminal 1; <2.4L engine>/terminal 4; <3.0L
engine>, and ground the battery (-) terminal to the body of the
compressor.

Q: Can the sound of the magnetic clutch (click) be heard?

YES : Go to Step 5.
NO : Replace. Then go to Step 11.

BATTERY
VOLTAGE

TERMINAL NO.
TO BE
CONNECTED TO
BATTERY

TERMINAL NO.
TO BE
CONDUCTED

SUPPLIED

1-3

4-5

NOT SUPPLIED

-

1-3

AC001366 AB

A/C COMPRESSOR RELAY

AC001367

1 2

3 4

AB

<2.4L ENGINE>

<3.0L ENGINE>

MAGNETIC CLUTCH
CONNECTOR

MAGNETIC CLUTCH
CONNECTOR

MANUAL A/C DIAGNOSIS

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HEATING AND AIR CONDITIONING

55-7

STEP 5. Check the dual pressure switch operation.
(1) Remove the dual pressure switch connector and connect

the high/low pressure side terminals located on the harness
side as shown in the illustration.

(2) Install a gauge manifold to the high-pressure side service

valve of the refrigerant line. (Refer to

P.55-22

.)

(3) When the high/low pressure sides of the dual pressure

switch are at operation pressure (ON) and the resistance is
less than 2 ohm between the respective terminals, then the
condition is normal. If open loop, replace the switch.

Q: Is the dual pressure switch operating properly?

YES : Go to Step 6.
NO : Replace the switch. Then go to Step 11.

STEP 6. Check the A/C switch continuity.

Q: Is the A/C switch continuity in good condition?

YES : Go to Step 7.
NO : Replace. Then go to Step 11.

STEP 7. Check the blower switch continuity.

Q: Is the blower switch continuity in good condition?

YES : Go to Step 8.
NO : Replace. Then go to Step 11.

ITEMS

SWITCH POSITION

OFF

→

ON

ON

→

OFF

Low-pressure side kPa
(psi)

221 (32.1)

196 (28.4)

High-pressure side kPa
(psi)

2,354 (341.4)

2,942 (426.7)

AC001368 AB

HIGH/LOW
PRESSURE SIDE

LOW-PRESSURE
SIDE

HIGH-PRESSURE
SIDE

ON

OFF

ON

OFF

SWITCH
POSITION

TESTER
CONNECTION
(CONNECTOR B)

SPECIFIED
CONDITION

Off

-

Open circuit

On

5-6

Less than two ohm

AC001370

OFF

ON

BLOWER
SWITCH
ASSEMBLY

AB

SWITCH
POSITION

TESTER
CONNECTION
(CONNECTOR A)

SPECIFIED
CONDITION

0 (OFF)

-

Open circuit

1 (LO)

3-5

Less than two ohm

2 (ML)

1-3

Less than two ohm

3 (MH)

3-6

Less than two ohm

4 (HI)

3-4

Less than two ohm

AC001371

BLOWER SWITCH
ASSEMBLY

AB

MANUAL A/C DIAGNOSIS

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HEATING AND AIR CONDITIONING

55-8

STEP 8. Check the refrigerant-temperature switch
operation.
When the A/C is off, check that there is less than 2 ohm
between the refrigerant-temperature switch terminals.

Q: Is the refrigerant-temperature switch in good condition?

YES : Go to Step 9.
NO : If the switch has an open circuit, replace the switch.

Then go to Step 11.

STEP 9. Measure the automatic compressor controller
terminal voltage.
Refer to

P.55-18

.

Q: Is the automatic compressor controller terminal voltage

good?
YES : Go to Step 10.
NO : Replace. Then go to Step 11.

STEP 10. Measure the engine control module <M/T>/the
powertrain control module <A/T> terminal voltage.
Refer to GROUP 13A, Diagnosis

−

Check at the Engine Control

Module (ECM) <M/T> or Powertrain Control Module (PCM) <A/
T> <2.4L engine>

P.13A-452

.

Refer to GROUP 13B, Diagnosis

−

Check at the Engine Control

Module (ECM) <M/T> or Powertrain Control Module (PCM) <A/
T> <3.0L engine>

P.13B-531

.

Q: Is the terminal voltage in good condition?

YES : Go to Step 11.
NO : Replace. Then go to Step 11.

STEP 11. Check symptoms.

Q: Is the A/C operating properly?

YES : This diagnosis is complete. (If no malfunctions are not

found in all steps, an intermittent malfunction is
suspected. Refer to GROUP 00E, How to Use
Troubleshooting/Inspection Service Points

−

How to

Cope with Intermittent Malfunction

P.00-6

.)

NO : Go to Step 1.

AC001372

REFRIGERANT
TEMPERATURE
SWITCH TERMINALS

AB