MPI <4G9> -
Troubleshooting
13A-123
Code No. P0551 Power Steering fluid Pressure Switch
System
Probable cause
Check Area
D
Intake air temperature is -10
_
C or higher.
D
Barometric pressure is 76 kPa or higher.
D
Engine coolant temperature is 30
_
C or more.
D
Repeat *1 drive and *2 stop ten times or more.
*1: Engine speed is 2,500 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.
Judgment Criteria
D
Power steering pressure switch remains on.
D
Power steering fluid pressure switch failed.
D
Open or shorted power steering fluid pressure
switch circuit or loose connector
D
Malfunction of engine-ECU <M/T>
D
Malfunction of engine-A/T-ECU <A/T>
NG
Repair
Replace the engine-ECU
<M/T> or engine-A/T-
ECU <A/T>.
OK
NG
Check the harness wire
between engine-ECU
<M/T> or engine-A/T-
ECU <A/T> and power
steering pressure switch
connector.
OK
Check the trouble
symptom.
OK
Replace the engine-ECU <M/T> or engine-A/T-ECU <A/T>.
OK
Check the trouble
symptom.
Repair
NG
OK
Check the following
connector:
A-78
NG
Repair
NG
Check the following
connectors:
A-10, A-78,
B-36 <M/T>, B-94 <A/T>
OK
Measure at the power steering pressure switch connector
A-78.
D
Disconnect the connector and measure at the harness
side.
D
Voltage between 1 and ground (Ignition switch: ON)
OK:
Battery positive voltage
OK
Check the following connector:
A-10
NG
Repair
OK
Transient malfunction (Refer to GROUP 00 - Points to Note
for Intermittent Malfunctions.)
NG
Check the power steering pressure switch.
(Refer to GROUP 37A - On-vehicle Service.)
NG
Replace
MUT-
II
Data list
27 Power steering fluid pressure switch
(Refer to P.13A-153, DATA LIST REFERENCE TABLE.)