Mitsubishi Electric Lancer Evolution-VII Workshop Manual page 1183

13A-46
Code No. P0551 Power steering fluid pressure switch
system
Range of Check
D Intake air temperature is - 10_C or higher.
D Barometric pressure is 76 kPa or more.
D Engine coolant temperature is 30_C or more.
D Repeat the *1 drive and *2 stop ten times or more.
*1: Engine speed is 2500 r/min or higher, volumetric efficiency is 55 % or higher and
vehicle speed is 5 km/h or higher for 4 seconds or more.
*2: Vehicle speed is 1.5 km/h or lower.
Set Conditions
D Power steering fluid pressure switch remains on.
Check the following connector: A-48
OK
Measure at the A-48 power steering
fluid pressure switch connector.
D Disconnect the connector to
measure at the harness side.
D Ignition switch: ON
D Voltage between terminal No. 1
and earth
OK: System voltage
OK
Measure at the C-122 engine-ECU connector.
D Measure the engine-ECU terminal voltage.
D Engine: Idling
D Voltage between terminal No. 37 and earth
D Steering wheel: Stationary state
OK: System voltage
D Steering wheel: Steered state
OK: 1 V or less
OK
Check the following connector: C-122
OK
MUT-II Data list
D No. 27: Power steering fluid pressure switch (Refer to
P.13A-103.)
NG
Replace the engine-ECU.
MPI -
Troubleshooting
NG
Repair
NG
Measure at the C-122 engine-ECU
connector.
D Measure the engine-ECU terminal
voltage.
D Ignition switch: ON
D Voltage between terminal No. 37
and earth
OK: System voltage
Check the following connectors:
C-122, C-136
Check the harness between the
power steering fluid pressure switch
and engine-ECU.
D Check for short-circuit of the
output cable.
MUT-II Data list
D No. 27: Power steering fluid
pressure switch (Refer to
P.13A-103.)
Replace the engine-ECU.
NG
NG
OK
Probable cause
D Power steering fliud pressure switch failed
D Open or short circuit in the power steering fluid
pressure switch circuit or loose conector contact
D Mulfunction of engine-ECU
OK
NG
NG
OK
NG
OK
OK
NG
Check the following connector:
C-122
OK
Check the harness between the
power steering fluid pressure switch
and engine-ECU.
D Check for damage of the output
cable.
OK
Replace the power steering fluid
pressure switch.
Repair
Intermittent malfunction (Refer to GROUP 00 - Points to Note
for Intermittent Malfunctions.)
Check the following connector:
C-126, C-136
NG
OK
Check and repair the harness
between the power steering fluid
pressure switch and engine-ECU.
D Check for disconnection of the
output cable.
Repair
Repair
Intermittent malfunction (Refer to
GROUP 00 - Points to Note for
Intermittent Malfunctions.)
NG
Repair
NG
Repair
Repair