2004 MITSUBISHI ENDEAVOR relay

Fig. 1: A/C Compressor Clutch Relay On Conditioning Chart

Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.

SERVICE PRECAUTIONS CAUTION LABELS The refrigerant gas warning label must be affixed in the location shown in the
figure on the left. Follow the instructions on the label when servicin
g.

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

INTRODUCTION TO HEATER, AIR CONDITIONING AND VENTILATION DIAGNOSISAir is drawn into the heater assembly from either the outside, or from the inside of
the passenger cabin if DEFROST, maximum cooling or RECIRCULATION are
selected. The air is then forced through the evaporator where heat is removed,
cooling and de-humidifying the air. Depending on the temperature selected, a
portion of this air is then forced through the heater core to achieve the selected
discharge temperature.
If the system does not cool properly, look for a problem with the refrigerant, blower
or air distribution systems. If the system does not heat properly, look for a problem
with the coolant, blower or air distribution systems. In either case all system fuses,
circuit breaker and relays should be checked. HEATER, AIR CONDITIONING AND VENTILATION DIAGNOSTIC TROUBLESHOOTING
STRATEGY 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
SYMPTOM CHART

4. Verify that the malfunction is eliminated.
DIAGNOSTIC FUNCTION HOW TO CONNECT THE SCAN TOOL (MUT-III) REQUIRED SPECIAL TOOL:

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)

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

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

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. 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