2005 MITSUBISHI 380 check engine light

ON-VEHICLE SERVICE
HEATER, AIR CONDITIONING AND VENTILATION55-149
A/C COMPRESSOR CLUTCH RELAY CONTINUITY
CHECK
IDLE-UP OPERATION CHECK
M1552001600401
Before inspection and adjustment, set vehicle in the following
condition:
Engine coolant temperature: 80 90 C (176.0 194.0 F)
Lights, electric cooling fan and accessories: OFF
Transmission: Neutral ("N" or "P" position)
Steering wheel: Straightforward
1. Check whether or not the idle speed is the standard value.
Standard value: 680
50 r/min
2. Turn on the air conditioning switch and the blower speed
selection dial. Engine idling speed should be within the
standard value:
Standard value: 680
50 r/min
NOTE: The Electronic control unit determines whether the
A/C load is low or high according to the output signal from
the A/C-ECU.
NOTE: It is not necessary to make an adjustment, because
the idling speed is automatically controlled by the ENGINE
ECU. BATTERY
V O LTA G ETESTER
CONNECTIONSPECIFIED
CONDITION
Not applied 1
4 Open circuit
Connect
terminal 2 to the
positive battery
terminal
Connect
terminal 3 to the
negative battery
terminal1
4 Less than 2 ohms

SPECIAL TOOLS
INTAKE AND EXHAUST15-3
INSPECTION PROCEDURE 2: Abnormal Noise
DIAGNOSIS
STEP 1. Start the engine. Have an assistant stay
in the drivers seat. Raise the vehicle on a hoist.
Have the assistant rev the engine while
searching for exhaust leaks.
Q: Is any abnormal noise generated?
YES :
Go to Step 2.
NO : The procedure is complete.
STEP 2. Check for missing parts in the muffler.
Tap the muffler lightly to check for loose baffles,
etc.
Q: Are there any missing parts in the muffler?
YES :
Replace, then go to Step 1.
NO : Go to Step 3.
STEP 3. Check the hanger for cracks.
Q: Is the hanger cracked?
YES :
Replace, then go to Step 1.
NO : Go to Step 4.
STEP 4. Check for interference of the pipes and
muffler with the body.
Q: Are the pipes and muffler interfering with the
body?
YES :
Repair, then go to Step 1.
NO : Go to Step 5.
STEP 5. Check the heat protectors.
Q: Are any heat protectors loose or damaged?
YES :
Tighten or replace, then go to Step 1.
NO : Go to Step 6.
STEP 6. Check the pipes and muffler for damage.
Q: Are the pipes and muffler damaged?
YES :
Replace, then go to Step 1.
NO : There is no action to be taken.
SPECIAL TOOLSM1151000600429
TOOL TOOL NUMBER AND
NAMESUPERSESSION APPLICATION
MD998412
GuideMD998412 Installation of intake
manifold plenum
MB991953
Oxygen sensor wrench- Removal and installation
of heated oxygen sensor
MD998770
Oxygen sensor wrenchMD998770-01 or General
service toolRemoval and installation
of heated oxygen sensor

CHARGING SYSTEM
ENGINE ELECTRICAL16-3
CHARGING SYSTEM DIAGNOSISM1161000700427
TROUBLESHOOTING HINTS
Alternator malfunction light dose not go on when the ignition
switch is turned to ON, before the engine starts.
Check the bulb.
Alternator malfunction light dose not switch off after the engine
starts.
Check the IC voltage regulator inside the
alternatoralternator.
Discharged or overcharged battery.
Check the IC voltage regulator inside the alternator.
The alternator malfunction light illuminates dimly.
Check the diode (inside the combination meter) for a
short-circuit.
TROUBLESHOOTING GUIDE
The charging system troubleshooting guide is shown in the fol-
lowing steps.
STEP 1.
Q: Is the battery in good condition? (Refer to GROUP 54A,
Chassis Electrical
Battery On-vehicle Service
Battery Check P.54A-5.)
YES : Go to Step 2.
NO : Charge or replace the battery.
STEP 2.
Q: Is the alternator drive belt in good condition? (Refer to
GROUP 00, General
Maintenance Service Drive Belts
(For Alternator, Power Steering Pump and Air
Conditioning) (Check) P.00-39.)
YES : Go to Step 3.
NO : Adjust the belt tension or replace the belt.
STEP 3.
Q: Does the alternator malfunction light come on when the
ignition switch is turned on?
YES : Go to Step 4.
NO :
Check the ignition switch. (Refer to GROUP 54A,
Chassis Electrical
Ignition Switch Ignition
Switch
Inspection P.54A-44.)
Check for burnt-out alternator malfunction light.
Check the alternator. (Refer to Charging System
Alternator Assembly
Inspection P.16-17.)
Check the alternator malfunction light-related
circuits.

CHARGING SYSTEM
ENGINE ELECTRICAL16-4
STEP 4.
Q: Does the alternator malfunction light go out after
starting the engine?
YES : Go to Step 5.
NO : Check the alternator (Refer to Charging System

Alternator Assembly
Inspection P.16-17.)
STEP 5.
Q: Is an oscilloscope available?
YES : Go to Step 6.
NO : Go to Step 7.
STEP 6.
Q: Does the oscilloscope show a normal wave pattern?
(Refer to Charging System
On-vehicle Service Wave
Pattern Check Using an Oscilloscope P.16-11.)
YES : Go to Step 7.
NO : Check the alternator. (Refer to Charging System

Alternator Assembly
Inspection P.16-17.)
STEP 7.
Engine: 2,500 r/min
Headlight: ON (high beam)
Voltage between alternator terminal B and the positive bat-
tery terminal
OK: 0.5 V or less
Voltage between the negative battery terminal and
alternator body
OK: 0.5 V or less
Q: Are the alternator output wire and ground wire in good
condition?
YES : Go to Step 8.
NO : Check the alternator output wire and ground wire.
STEP 8.
Q: Is the output current normal? (Refer to Charging
System
On-vehicle Service Output Current Test
P.16-8.)
YES : Go to Step 9.
NO : Check the alternator (Refer to Charging System

Alternator Assembly
Inspection P.16-17.)

CHARGING SYSTEM
ENGINE ELECTRICAL16-8
10.With the engine running at 2,500 r/min, turn the
headlights and other lights on and off to adjust the
alternator load so that the value displayed on the
ammeter is slightly above 30 A.
Read the voltmeter. Voltage reading at or below
limit value means voltage drop between alternator
and battery is OK.
Limit value: maximum 0.3 V
NOTE: When the alternator output is high and the
value displayed on the ammeter does not
decrease to 30 A, set the value to 40 A. Read the
value displayed on the voltmeter at this time.
In this case the limit value becomes maximum 0.4
V.
Adjust the engine speed by gradually decreasing
it until the value displayed on the ammeter is 30
A. Take a reading of the value displayed on the
voltmeter at this time.11.If the value displayed on the voltmeter is above
the limit value, there is probably a malfunction in
the alternator output wire. Check the wiring
between the alternator "B" terminal and the
positive battery terminal (including fusible link).
If a terminal is not sufficiently tight or if the
harness has become discolored due to
overheating, repair and then test again.
12.After the test, run the engine at idle.
13.Turn off all lights and turn the ignition switch to the
"LOCK" (OFF) position.
14.Disconnect the engine tachometer or diagnostic
tool.
15.Disconnect the negative battery cable.
16.Disconnect the ammeter and voltmeter.
17.Connect the negative battery cable.
18.Run the engine for 10 minutes at an idle.
OUTPUT CURRENT TESTM1161001000670

CHARGING SYSTEM
ENGINE ELECTRICAL16-9
Required Special Tool:
: Diagnostic Tool (MUT-III)
MB991824: V.C.I.
MB991827: MUT-III USB Cable
MB991910: MUT-III Main Harness A
This test determines whether the alternator outputs
normal current. For best results, use a charging sys-
tem tester. If not available, follow the steps below.
Battery posts, terminals and related acces-
sories contain lead and lead compounds.
WASH HANDS AFTER HANDLING.
1. Before the test, always be sure to check the
following.
Alternator installation
Battery (Refer to GROUP 54A, Chassis Electrical
Battery On-vehicle Service Battery Check
P.54A-5.)
NOTE: The battery to be used should be slightly
discharged. The load in a fully-charged battery
will be insufficient and the test may not be able to
be carried out correctly.
Alternator drive belt tension (Refer to GROUP 00,
General
Maintenance Service Drive Belts
(For Alternator, Power Steering Pump and Air
Conditioning) (Check) P.00-39.)
Fusible link
Abnormal noise from the alternator while the
engine is running.
2. Turn the ignition switch to the "LOCK" (OFF)
position.
3. Disconnect the negative battery cable.
Never use clips to connect the wire. Loose
connections (for example, using clips) will
lead to a serious accident because of high
current.
4. Connect a clamp-type DC test ammeter with a
range of 0
120 A to the alternator "B" terminal
output wire.
5. Connect a voltmeter with a range of 0
20 V
between the alternator "B" terminal and ground.
(Connect the positive lead of the voltmeter to the
"B" terminal, and then connect the negative lead
of the voltmeter to ground.)
6. Connect the negative battery cable.
7. Connect an engine tachometer or diagnostic tool.
8. Leave the hood open.9. Check to be sure that the reading on the voltmeter
is equal to the battery positive voltage.
NOTE: If the voltage is 0 V, the cause is probably
an open circuit in the wire or fusible link between
the alternator "B" terminal and the battery positive
terminal or malfunctioning voltmeter.
10.After turning on the headlights, start the engine.
NOTE: Because the current from the battery will
soon drop after the engine is started, step 11
should be carried out as quickly as possible in
order to obtain the maximum current output value.
11.Immediately after setting the headlights to high
beam and turning the heater blower switch to the
highest position, increase the engine speed to
2,500 r/min and read the maximum current output
value displayed on the ammeter.
Limit value: 70 % of nominal current output
NOTE: For the nominal current output, refer to the
Alternator Specifications.
NOTE: The current output value will depend on
the electrical load and the temperature of the
alternator body.
NOTE: If the electrical load is small while testing,
the specified level of current may not be output
even though the alternator is normal. In such
cases, increase the electrical load by leaving the
headlights turned on for some time to discharge
the battery or by using the lighting system in
another vehicle, and then test again.
NOTE: The specified level of current also may not
be output if the temperature of the alternator body
or the ambient temperature is too high. In such
cases, cool the alternator and then test again.
12.The reading on the ammeter should be above the
limit value. If the reading is below the limit value
and the alternator output wire is normal, remove
the alternator from the engine and check the
alternator.
13.Run the engine at idle speed after the test.
14.Turn the ignition switch to the "LOCK" (OFF)
position.
15.Disconnect the engine tachometer or diagnostic
tool.
16.Disconnect the negative battery cable.
17.Disconnect the ammeter and voltmeter .
18.Connect the negative battery cable.
19.Run the engine for 10 minutes at an idle.

CHARGING SYSTEM
ENGINE ELECTRICAL16-10
REGULATED VOLTAGE TESTM1161001100666
Required Special Tools:
: Diagnostic Tool (MUT-III)
MB991824: V.C.I.
MB991827: MUT-III USB Cable
MB991910: MUT-III Main Harness A
MB998467: Alternator Harness Connector
This test determines whether the voltage regulator is
correctly controlling the alternator output voltage.
Battery posts, terminals and related acces-
sories contain lead and lead compounds.
WASH HANDS AFTER HANDLING.
1. Always be sure to check the following before the
test:
Alternator installation
Check to be sure that the battery installed in the
vehicle is fully charged. (Refer to GROUP 54A,
Chassis Electrical
Battery On-vehicle Service
Battery Check P.54A-5.)
Alternator drive belt tension (Refer to GROUP 00,
General
Maintenance Service Drive Belts
(For Alternator, Power Steering Pump and Air
Conditioning) (Check) P.00-39.)
Fusible link
Abnormal noise from the alternator while the
engine is running.2. Turn the ignition switch to the "LOCK" (OFF)
position.
3. Disconnect the negative battery cable.
4. Use the special tool (Alternator harness
connector: MB998467) to connect a digital-type
voltmeter between the alternator "S" terminal and
ground. (Connect the positive lead of the
voltmeter to the "S" terminal, and then connect the
negative lead of the voltmeter to a secure ground
or to the negative battery terminal.)
5. Connect a clamp-type DC test ammeter with a
range of 0
120 A to the alternator "B" terminal
output wire.
6. Reconnect the negative battery cable.
7. Connect an engine tachometer, or diagnostic tool.
8. Turn the ignition switch to the "ON" position and
check that the reading on the voltmeter is equal to
the battery positive voltage.
NOTE: If the voltage is 0 V, the cause is probably
an open circuit in the wire or fusible link between
the alternator "S" terminal and the battery positive
terminal or malfunctioning voltmeter.
9. Check to be sure that all lights and accessories
are off.
10.Start the engine.

CHARGING SYSTEM
ENGINE ELECTRICAL16-12
NOTE: The voltage waveform of the alternator "B" terminal can
undulate as shown at left. This waveform is produced when the
regulator operates according to fluctuations in the alternator
load (current), and is normal for the alternator.
If the ripple height is abnormally high (approximately 2 V or
more during idling), the wires between the alternator "B" termi-
nal and the battery have broken due to fuse blowing, etc. The
alternator is usually operating properly.
.
ABNORMAL WAVEFORMS EXAMPLES
NOTE: The size of the waveform patterns can differ greatly,
depending on the adjustment of the variable knob on the oscil-
loscope.
NOTE: Identification of abnormal waveforms is easier when
there is a large output current (regulator is not operating).
(Waveforms can be observed when the headlights are illumi-
nated.)
NOTE: Check the conditions of the alternator malfunction light
(illuminated/not illuminated) also, and carry out a total check.
ABNORMAL WAVEFORMS
Example 1
PROBABLE CAUSE: Open circuit in diode