Mitsubishi Lancer Evolution 8. Manual — part 171
MPI – TROUBLESHOOTING
13A-70
Checking Procedure 26
C-51 Engine ECU connector
measurement
• Engine ECU terminal voltage
measurement
• Engine idling
• A/C set temp
When cabin temp. 25ºC or more:
Max. Cool
When cabin temp. 25ºC or less:
Max. Hot
• Voltage across 45 - earth
• A/C switch: ON
(A/C compressor operating)
OK: Battery voltage
• A/C switch OFF
OK: 0.5V or less
Check connector C-51
MUT-II/III Service Data
• No.28: A/C switch
• Engine idling
• A/C set temp
When cabin temp. 25ºC or more:
Max. Cool
When cabin temp. 25ºC or less:
Max. Hot
• A/C switch: ON
OK: ON
• A/C switch OFF
OK: OFF
Check A/C system
(ref. Chapter 55 – Troubleshooting)
Intermittent malfunction (ref.
Chapter 00 – Intermittent
Malfunctions)
Replace engine ECU
A/C Switch System
Probable causes
When the control panel A/C switch is turned ON, the A/C switch ON signal
is input to the engine ECU. As a result, the engine ECU turns the A/C
compressor ON.
• Control panel A/C switch malfunction
• A/C system malfunction
• Engine ECU malfunction
NG
NG
NG
OK
OK
OK
Repair
MPI – TROUBLESHOOTING
13A-71
Checking Procedure 27
Check connector B20-X
Check A/C compressor relay
(ref. Chapter 55A – Vehicle Servicing)
Replace A/C compressor relay
B-20X A/C compressor relay
connector measurement
• Take measurement on
connector side from which relay
was taken out
(1) Voltage across 2 - earth
(Ignition switch: ON)
OK: Battery voltage
(2) Voltage across 1 – earth
OK: Battery voltage
Check connector A -39
A-39 A/C compressor connector
measurement
• Undo connector, then take
measurement on harness side
• Remove B-20X A/C compressor
relay, then create a short circuit
between harness side connector
terminals 1 - 4
• Ignition switch: ON
• Voltage across 1 – earth
OK: Battery voltage
C-49 Engine ECU connector
measurement
• Engine ECU terminal voltage
measurement
• Ignition switch: ON
• Voltage across 20 – earth
OK: Battery voltage
To next page
Check connector C-20, C-119,
C-209, C-210, C-201
Check and repair harness
between ignition switch and A/C
compressor relay
• Check to see if power supply cable
is broken or has a short circuit
Check connector C-34
Check and repair harness
between battery and radiator fan
control relay
• Check to see if power supply
cable is broken or has short circuit
Check connector C-34
Check harness between A/C
compressor relay and A/C
compressor
• Check output wire cable for any
damage
Check connector C-49
Check harness between A/C
compressor relay and engine
ECU
• Check to see if earth wire is
broken or damaged
MUT-II/III Service Data
• No.49: A/C relay
• Engine idling
• A/C set temp
When cabin temp. 25°C or
more:
Max. Cool
When cabin temp. 25°C or less:
Max. Hot
• A/C switch: ON
OK: ON
• A/C switch OFF
OK: OFF
Intermittent malfunction (ref.
Chapter 00 – Intermittent
Malfunctions)
Replace engine ECU
A/C Compressor System
Probable causes
When the A/C switch ON signal is input to the engine ECU,
the engine ECU turns the A/C compressor relay ON.
As a result, the A/C compressor magnet clutch operates.
• A/C compressor relay malfunction
• A/C compressor magnet clutch malfunction
• Engine ECU malfunction
OK
OK
OK
OK
OK
OK
OK
OK
OK
OK
OK
NG
NG
(1) NG
OK
NG
NG
NG
NG
OK
NG
(
1) NG
(
2) NG
NG
NG
Repair
Repair
Repair
Repair
Repair
Repair
Repair
MPI – TROUBLESHOOTING
13A-72
From previous page
Check connectors C-20, C-119, C-209, C-210, C-201
Check harness between ignition switch and A/C
compressor relay
• Check power supply cable for any damage
Check connector C-34
Check harness between fan controller and engine ECU
• Check power supply cable for any damage
Check harness between A/C compressor relay and
engine ECU
• Check for any damage to earth wire
Check harness between A/C compressor relay and A/C
compressor
• Check for any damage to output cable
Replace A/C compressor magnet clutch
OK
NG
NG
NG
NG
NG
NG
OK
OK
OK
OK
OK
OK
Repair
Repair
Repair
Repair
Repair
Repair
MPI – TROUBLESHOOTING
13A-73
Checking Procedure 28
C-50 Engine ECU connector
measurement
• Engine ECU terminal voltage
measurement
• Engine: idling
• A/C switch: ON
(A/C compressor operating
condition)
• Voltage across 65 – earth
• A/C set temperature:
Minimum temperature
Air flow: Maximum (Max. cool)
Atmospheric air temp. sensor
ambient temp.: at least 18°C
OK: 1V or less
• A/C set temp.: Cabin
temperature
Air flow: Minimum
OK: battery voltage
Check connector C-50
C-16 A/C-ECU connector
< manual A/C > or C-18 A/C-ECU
connector <auto-A/C)
measurement
• A/C-ECU terminal voltage
measurement
• Engine: idling
• A/C set temp
When cabin temp. 25ºC or more:
Max. Cool
When cabin temp. 25ºC or less:
Max. Hot
• A/C switch: ON
• Voltage across 2 – earth
<Manual A/C>
• Voltage across 32 - earth
<Auto A/C>
OK: Battery voltage
Check connector C-16 <Manual
A/C>, C-18 <Auto A/C>, C-20
Check and repair harness
between engine ECU and A/C-
ECU
• Check to see if output wire is
broken
Check connector C-50
Confirm fault symptoms
Replace Engine ECU
Check connector C-16 <Manual
A/C>, C-18 <Auto A/C>, C-20
Check harness between engine
ECU and A/C-ECU
• Check output wire for short
circuits
Check A/C system
(ref. Chapter 55A –
Troubleshooting)
Intermittent fault (ref. Chapter 00
– Intermittent Malfunctions)
A/C Load Signal System
Probable causes
Detects the size of the A/C compressor load, which depends
on differences in the set temperature. When a high A/C load
signal is input to the engine ECU, the engine ECU decides
that the A/C compressor load is high and operates the throttle
valve control servo so that idling speed increases.
• A/C-ECU malfunction
• Engine ECU malfunction
NG
NG
NG
NG
NG
NG
NG
OK
OK
OK
OK
OK
OK
OK
NG
OK
Repair
Repair
Repair
Repair
Repair
Нет комментариевНе стесняйтесь поделиться с нами вашим ценным мнением.
Текст