Ignition MITSUBISHI 380 2005 Workshop Manual

AUTO A/C DIAGNOSIS
HEATER, AIR CONDITIONING AND VENTILATION55-91
STEP 2. Measure the voltage at blower motor connector
C-115.
(1) Disconnect blower motor connector C-115, and measure
the voltage at the wiring harness side.
(2) Disconnect A/C-ECU connector C-15 and ground harness
side terminal No.9.
(3) Turn the ignition switch to the "ON" position.
(4) Measure the voltage between C-115 (terminal 1) and
ground.
The measured value should be approx. 12 volts (battery
positive voltage).
Q: Is the measured voltage approx. 12 volts?
YES : Go to Step 11.
NO : Go to Step 3.
STEP 3. Check blower relay connector C-202 for loose,
corroded or damaged terminals, or terminals pushed back
in the connector.
Q: Is blower relay connector C-202 in good condition?
YES : Go to Step 4.
NO : Repair or replace the connector. Refer to GROUP
00E, Harness Connector Inspection P.00E-2.The
blower motor should operate normally.

AUTO A/C DIAGNOSIS
HEATER, AIR CONDITIONING AND VENTILATION55-92
STEP 4. Check the blower relay continuity.
Follow the table below to check the blower relay for continuity.
Q: Is the blower relay continuity in good condition?
YES : Go to Step 5.
NO : Replace the blower relay. The blower motor should
operate normally.
STEP 5. Measure the voltage at blower relay connector
C-202.
(1) Disconnect blower relay connector C-202, and measure the
voltage at the junction block side.
(2) Turn the ignition switch to the "ON" position.
(3) Measure the voltage between terminal 1 and ground.
The measured value should be approximately 12 volts
(battery positive voltage).
Q: Is the measured voltage approx. 12 volts?
YES : Go to Step 7.
NO : Go to Step 6. BATTERY
VOLTAGETESTER
CONNECTIONSPECIFIED
CONDITION
Not applied 4
5 Open circuit
Connect
terminal 1 to the
positive battery
terminal
Connect
terminal 3 to the
negative battery
terminal4
5 Less than 2 ohms

AUTO A/C DIAGNOSIS
HEATER, AIR CONDITIONING AND VENTILATION55-93
STEP 6. Check the wiring harness between blower relay
connector C-202 (terminal 1) and the ignition switch (IG2).
NOTE: Also check junction block connector C-215 for loose,
corroded, or damaged terminals, or terminals pushed back in
the connector. If junction block connector C-215 is damaged,
repair or replace the connector as described in GROUP 00E,
Harness Connector Inspection P.00E-2.
Q: Is the wiring harness between blower relay connector
C-202 (terminal 1) and the ignition switch (IG2) in good
condition?
YES : It can be assumed that this malfunction is intermittent.
Refer to GROUP 00, How to Use
Troubleshooting/Inspection Service Points
How to
Cope with Intermittent Malfunctions P.00-14.
NO : Repair the wiring harness. The blower motor should
operate normally.

AUTO A/C DIAGNOSIS
HEATER, AIR CONDITIONING AND VENTILATION55-104
INSPECTION PROCEDURE 7: The A/C Indicator Flashes.
.
TECHNICAL DESCRIPTION (COMMENT)
If the A/C indicator flashes, inadequate refrigerant
quantity, the ambient air temperature sensor circuit
or the A/C pressure sensor circuit is suspected.
.
TROUBLESHOOTING HINTS
Malfunction of the A/C pressure sensor
Malfunction of the ambient air temperature sen-
sor
Malfunction of the A/C-ECU
Refer to component locations GROUP-70
Refer to configuration diagrams GROUP-80
Refer to circuit diagrams GROUP-90
DIAGNOSIS
Required Special Tools:
MB991223: Test Harness Set
: 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. Using scan tool , read the diagnostic trouble code.
Check if an A/C-ECU DTC is set.
(1) Connect scan tool to the data link connector.
(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 2.
NO : Refer to DIAGNOSTIC TROUBLE CODE CHART
P.55-9.

AUTO A/C DIAGNOSIS
HEATER, AIR CONDITIONING AND VENTILATION55-105
STEP 2. Using scan tool , check data list item 61: A/C
pressure sensor.
To prevent damage to scan tool , always turn the ignition
switch to the "LOCK" (OFF) position before connecting or
disconnecting scan tool .
(1) Connect scan tool 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 to the data reading mode for item 61: 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.

AUTO A/C DIAGNOSIS
HEATER, AIR CONDITIONING AND VENTILATION55-113
STEP 5.Measure the voltage at choke coil connector D-11.
(1) Disconnect connector D-11, and measure the voltage at the
harness side.
(2) Disconnect A/C-ECU connector C-15 and ground harness
side terminal No.27.
(3) Turn the ignition switch to the "ON" position.
(4) Measure the voltage between choke coil connector D-11
terminal No.1 and ground.
The measured value should be approximately 12 volts.
Q: Is the measured voltage approx. 12 volts?
YES : Go to Step 13.
NO : Go to Step 6.

AUTO A/C DIAGNOSIS
HEATER, AIR CONDITIONING AND VENTILATION55-116
STEP 8. Measure the voltage at defogger relay connector
C-201.
(1) Disconnect defogger relay connector C-201, and measure
the voltage at the junction block side.
(2) Turn the ignition switch to the "ON" position.
(3) Measure the voltage between terminal 1 and ground.
The measured value should be approximately 12 volts
(battery positive voltage).
Q: Is the measured voltage approx. 12 volts?
YES : Go to Step 10.
NO : Go to Step 9.
STEP 9. Check the wiring harness between defogger relay
connector C-201 (terminal 1) and ignition switch (IG2).

AUTO A/C DIAGNOSIS
HEATER, AIR CONDITIONING AND VENTILATION55-117
NOTE: Also check junction block connector C-215 for loose,
corroded, or damaged terminals, or terminals pushed back in
the connector. If junction block connector C-215 is damaged,
repair or replace the connector as described in GROUP 00E,
Harness Connector Inspection P.00E-2.
Q: Is the wiring harness between defogger relay connector
C-201 (terminal 1) and ignition switch (IG2) in good
condition?
YES : It can be assumed that this malfunction is intermittent.
Refer to GROUP 00, How to Use
Troubleshooting/Inspection Service Points
How to
Cope with Intermittent Malfunctions P.00-14.
NO : Repair the wiring harness. Check that the defogger
system works normally.
STEP 10. Check A/C-ECU connector C-15 for loose,
corroded or damaged terminals, or terminals pushed back
in the connector.
Q: Is A/C-ECU connector C-15 in good condition?
YES : Go to Step 11.
NO : Repair or replace the connector. Refer to GROUP
00E, Harness Connector Inspection P.00E-2. Check
that the defogger system works normally.

AUTO A/C DIAGNOSIS
HEATER, AIR CONDITIONING AND VENTILATION55-123
STEP 2. Measure the voltage at A/C-ECU connector C-16.
(1) Disconnect A/C-ECU connector C-16 and measure the
voltage at the harness side.
(2) Turn the ignition switch to the "ON" position.
(3) Measure the voltage between terminal 28 and ground.
The measured value should be approximately 12 volts
(battery positive voltage).
Q: Is the measured voltage approx. 12 volts?
YES : Go to Step 4.
NO : Go to Step 3.
STEP 3. Check the wiring harness between A/C-ECU
connector C-16 (terminal 28) and the ignition switch (IG2).

AUTO A/C DIAGNOSIS
HEATER, AIR CONDITIONING AND VENTILATION55-124
NOTE: Also check junction block connectors C-211 and C-215
for loose, corroded, or damaged terminals, or terminals pushed
back in the connector. If junction block connector C-211 or
C-215 is damaged, repair or replace the connector as
described in GROUP 00E, Harness Connector Inspection
P.00E-2.
Q: Is the wiring harness between A/C-ECU connector C-16
(terminal 28) and the ignition switch (IG2) in good
condition?
YES : It can be assumed that this malfunction is intermittent.
Refer to GROUP 00, How to Use
Troubleshooting/Inspection Service Points
How to
Cope with Intermittent Malfunctions P.00-14.
NO : Repair the wiring harness. Check that the air
conditioning works normally.
STEP 4. Measure the voltage at A/C-ECU connector C-16.
(1) Disconnect A/C-ECU connector C-16 and measure the
voltage at the harness side.
(2) Turn the ignition switch to the "ACC" position.
(3) Measure the voltage between terminal 36 and ground.
The measured value should be approximately 12 volts
(battery positive voltage).
Q: Is the measured voltage approx. 12 volts?
YES : Go to Step 6.
NO : Go to Step 5.