2004 MITSUBISHI ENDEAVOR Ac compressor

relay system may be defective. TROUBLESHOOTING HINTS
Improper amount of refrigerant Malfunction of the air thermo sensor Malfunction of the ambient air temperature sensor Malfunction of the A/C pressure sensor Malfunction of the A/C compressor clutch relay Malfunction of the A/C refrigerant temperature switch Malfunction of the air conditioning compressor clutch Malfunction of the A/C-ECU Malfunction of the PCM Damaged harness wires or connectors
DIAGNOSIS REQUIRED SPECIAL TOOLS:

MB991223: Test Harness Set MB991958: Scan Tool (MUT-III Sub Assembly)
MB991824: Vehicle Communication Interface (V.C.I.) MB991827: MUT-III USB Cable MB991910: MUT-III Main Harness A (Vehicles with CAN
communication system)
STEP 1. Check the defogger and outside/inside air selection damper
control motor operation.

Q: Do the defogger and outside/inside air selection damper control motor
work normally?

YES:
Go to Step 2.
NO:
Refer to
INSPECTION PROCEDURE 10 MALFUNCTION OF
THE A/C
-ECU POWER SUPPLY SYSTEM
.

2004 Mitsubishi Endeavor LS
2004 HVAC Heater Air Conditioning, Ventilation - Endeavor

STEP 2. Check the blower motor operation.

Q: Does the blower motor work normally?

YES:
Go to Step 3.
NO:
Refer to
INSPECTION PROCEDURE 5 BLOWER FAN AND
MOTOR DO NOT TURN
.
STEP 3. Check the A/C compressor.

Check the A/C compressor for compressor oil leaks.
Q: Is the check result satisfactory?

YES:
Go to Step 4.
NO:
Replace the A/C compressor or the expansion valve.
STEP 4. Using scan tool MB991958, read the diagnostic trouble code.

Check if an A/C-ECU DTC is set.
1. Connect scan tool MB991958 to the data link connec
tor.

2004 Mitsubishi Endeavor LS
2004 HVAC Heater Air Conditioning, Ventilation - Endeavor

2. Turn the ignition switch to the "ON" position
3. Check if the DTC is set.
4. Turn the ignition switch to the "LOCK" (OFF) position. Q: Is the check result satisfactory?

YES:
Go to Step 5.
NO:
Refer to
DIAGNOSTIC TROUBLE CODE CHART
.
STEP 5. Check A/C compressor clutch relay connector B-16X for loose,
corroded or damaged terminals, or terminals pushed back in the
connector.

Q: Is A/C compressor clutch relay connector B-16X in good condition?

YES:
Go to Step 6.
NO:
Repair or replace the connector. Refer to
HARNESS
CONNECTOR INSPECTION
. Check that the air conditioning works
normall
y.

2004 Mitsubishi Endeavor LS
2004 HVAC Heater Air Conditioning, Ventilation - Endeavor

Fig. 132: Locating Connector B
-16X

Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.

STEP 6. Check the A/C compressor clutch relay continuity.

Follow the table below to check the A/C compressor clutch relay for
continuit
y.

2004 Mitsubishi Endeavor LS
2004 HVAC Heater Air Conditioning, Ventilation - Endeavor

Fig. 133: Checking A/C Compressor Clutch Relay For Continuity

Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.

Fig. 134: A/C Compressor Clutch Relay

Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.

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

YES:
Go to Step 7.
NO:
Replace the A/C compressor clutch relay. Check that the air
conditioning works normally.
STEP 7. Check powertrain control module connector B-20 and A/C
compressor assembly B-114 for loose, corroded or damaged terminals, or
terminals pushed back in the connector.

Q: Are powertrain control module connector B-20 and A/C compressor
assembly B-114 in good condition?

YES:
Go to Step 8.
NO:
Repair or replace the connector. Refer to
HARNESS
CONNECTOR INSPECTION
. Check that the air conditionin
g works

2004 Mitsubishi Endeavor LS
2004 HVAC Heater Air Conditioning, Ventilation - Endeavor

Fig. 136: Locating Connector B
-114

Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.

STEP 8. Measure the voltage at A/C compressor assembly connector B-
114.

1. Disconnect A/C compressor assembly connector B-114 and measure the
volta
ge at the rela
y box side.

2004 Mitsubishi Endeavor LS
2004 HVAC Heater Air Conditioning, Ventilation - Endeavor

Fig. 140: Measuring Voltage Between Terminal 1 And Ground

Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.

The measured value should be approximately 12 volts (battery
positive voltage).
Q: Is the measured voltage approx. 12 volts?

YES:
Go to Step 15 .
NO:
Go to Step 9.
STEP 9. Measure the voltage at A/C compressor clutch relay connector B-
16X.
CAUTION: The top and bottom of the A/C compressor

2004 Mitsubishi Endeavor LS
2004 HVAC Heater Air Conditioning, Ventilation - Endeavor

1. Disconnect A/C compressor connector B-16X and measure the voltage at
the relay box side.
2. Turn the ignition switch to the "ON" position.
Fig. 141: Locating Connector B
-16X

Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.

3. Measure the voltage between terminal 2 and ground.
The measured value should be approximately 12 volts (battery
positive voltage).
connector are difficult to identify. Prior to
inspection, confirm the trian
gle mark on the rela
y
box.

2004 Mitsubishi Endeavor LS
2004 HVAC Heater Air Conditioning, Ventilation - Endeavor