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EC-346Revision: August 2007
DTC P0550 PSP SENSOR
2004 QX56
DTC P0550 PSP SENSORPFP:49763
Component DescriptionUBS00H6P
Power steering pressure (PSP) sensor is installed to the power
steering high-pressure tube and detects a power steering load. This
sensor is a potentiometer which transforms the power steering load
into output voltage, and emits the voltage signal to the ECM. The
ECM controls the electric throttle control actuator and adjusts the
throttle valve opening angle to increase the engine speed and
adjusts the idle speed for the increased load.
CONSULT-II Reference Value in Data Monitor ModeUBS00H6Q
Specification data are reference values.
On Board Diagnosis LogicUBS00H6R
The MIL will not light up for this diagnosis.
NOTE:
If DTC P0550 is displayed with DTC P1229, first perform the trouble diagnosis for DTC P1229. Refer to
EC-424, "
DTC P1229 SENSOR POWER SUPPLY" .
DTC Confirmation ProcedureUBS00H6S
NOTE:
If DTC Confirmation Procedure has been previously conducted, always turn ignition switch OFF and wait at
least 10 seconds before conducting the next test.
WITH CONSULT-II
1. Turn ignition switch ON.
2. Select “DATA MONITOR” mode with CONSULT-II.
3. Start engine and let it idle for at least 5 seconds.
4. If 1st trip DTC is detected, go to EC-348, "
Diagnostic Procedure"
.
WITH GST
Follow the procedure “WITH CONSULT-II” above.
BBIA0365E
MONITOR ITEM CONDITION SPECIFICATION
PW/ST SIGNAL
Engine: After warming up, idle
the engineSteering wheel is in neutral position.
(Forward direction)OFF
Steering wheel is turned. ON
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P0550
0550Power steering pressure
sensor circuitAn excessively low or high voltage from the
sensor is sent to ECM.
Harness or connectors
(The sensor circuit is open or shorted)
Power steering pressure sensor
SEF 0 58 Y
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DTC P0550 PSP SENSOR
EC-347
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Wiring DiagramUBS00H6T
BBWA11 76 E
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EC-348Revision: August 2007
DTC P0550 PSP SENSOR
2004 QX56
Specification data are reference values and are measured between each terminal and ground.
CAUTION:
Do not use ECM ground terminals when measuring input/output voltage. Doing so may result in dam-
age to the ECM's transistor. Use a ground other than ECM terminals, such as the ground.
Diagnostic ProcedureUBS00H6U
1. CHECK GROUND CONNECTIONS
1. Turn ignition switch OFF.
2. Loosen and retighten three ground screws on the body.
Refer to EC-133, "
Ground Inspection" .
OK or NG
OK >> GO TO 2.
NG >> Repair or replace ground connections.
TER-
MINAL
NO.WIRE
COLORITEM CONDITION DATA (DC Voltage)
12 RPower steering pressure
sensor[Engine is running]
Steering wheel is being turned.0.5 - 4.5V
[Engine is running]
Steering wheel is not being turned.0.4 - 0.8V
67 B Sensor ground[Engine is running]
Warm-up condition
Idle speedApproximately 0V
68 W/LSensor power supply
(Power steering pressure
sensor)[Ignition switch: ON]Approximately 5V
BBIA0354E
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DTC P0550 PSP SENSOR
EC-349
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2. CHECK PSP SENSOR POWER SUPPLY CIRCUIT
1. Disconnect PSP sensor harness connector.
2. Turn ignition switch ON.
3. Check voltage between PSP sensor terminal 1 and ground with
CONSULT-II or tester.
OK or NG
OK >> GO TO 3.
NG >> Repair harness or connectors.
3. CHECK PSP SENSOR GROUND CIRCUIT FOR OPEN AND SHORT
1. Turn ignition switch OFF.
2. Disconnect ECM harness connector.
3. Check harness continuity between PSP sensor terminal 3 and ECM terminal 67.
Refer to Wiring Diagram.
4. Also check harness for short to ground or short to power.
OK or NG
OK >> GO TO 4.
NG >> Repair open circuit or short to ground or short to power in harness or connectors.
4. CHECK PSP SENSOR INPUT SIGNAL CIRCUIT FOR OPEN AND SHORT
1. Check harness continuity between ECM terminal 12 and PSP sensor terminal 2.
2. Also check harness for short to ground and short to power.
OK or NG
OK >> GO TO 5.
NG >> Repair open circuit or short to ground or short to power in harness or connectors.
5. CHECK PSP SENSOR
Refer to EC-350, "
Component Inspection" .
OK or NG
OK >> GO TO 6.
NG >> Replace PSP sensor.
BBIA0365E
Voltage: Approximately 5V
PBIB0188E
Continuity should exist.
Continuity should exist.
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EC-350Revision: August 2007
DTC P0550 PSP SENSOR
2004 QX56
6. CHECK INTERMITTENT INCIDENT
Refer to EC-127, "
TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT" .
>>INSPECTION END
Component InspectionUBS00H6V
POWER STEERING PRESSURE SENSOR
1. Reconnect all harness connectors disconnected.
2. Start engine and let it idle.
3. Check voltage between ECM terminal 12 and ground under the
following conditions.
Removal and Installation UBS00H6W
POWER STEERING PRESSURE SENSOR
Refer to PS-31, "HYDRAULIC LINE" .
Condition Voltage
Steering wheel is being turned. 0.5 - 4.5V
Steering wheel is not being turned. 0.4 - 0.8V
MBIB0126E
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DTC P0605 ECM
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DTC P0605 ECMPFP:23710
Component DescriptionUBS00H6X
The ECM consists of a microcomputer and connectors for signal
input and output and for power supply. The ECM controls the engine.
On Board Diagnosis LogicUBS00H6Y
This self-diagnosis has one or two trip detection logic.
FAIL-SAFE MODE
ECM enters fail-safe mode when the malfunction A is detected.
DTC Confirmation ProcedureUBS00H6Z
Perform PROCEDURE FOR MALFUNCTION A first. If the 1st trip DTC cannot be confirmed, perform
PROCEDURE FOR MALFUNCTION B. If there is no malfunction on PROCEDURE FOR MALFUNCTION
B, perform PROCEDURE FOR MALFUNCTION C.
NOTE:
If DTC Confirmation Procedure has been previously conducted, always turn ignition switch OFF and wait at
least 10 seconds before conducting the next test.
PROCEDURE FOR MALFUNCTION A
With CONSULT-II
1. Turn ignition switch ON.
2. Select “DATA MONITOR” mode with CONSULT-II.
3. If 1st trip DTC is detected, go to EC-352, "
Diagnostic Procedure"
.
With GST
Follow the procedure “With CONSULT-II” above.
PBIB11 64 E
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P0605
0605Engine control moduleA) ECM calculation function is malfunctioning.
ECM B) ECM EEP-ROM system is malfunctioning.
C) ECM self shut-off function is malfunctioning.
Detected items Engine operation condition in fail-safe mode
Malfunction A
ECM stops the electric throttle control actuator control, throttle valve is maintained at a fixed opening (approx.
5 degrees) by the return spring.
ECM deactivates ASCD operation.
SEF 0 58 Y
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EC-352Revision: August 2007
DTC P0605 ECM
2004 QX56
PROCEDURE FOR MALFUNCTION B
With CONSULT-II
1. Turn ignition switch ON and wait at least 1 second.
2. Select “DATA MONITOR” mode with CONSULT-II.
3. Turn ignition switch OFF, wait at least 10 seconds and then turn
ON.
4. If 1st trip DTC is detected, go to EC-352, "
Diagnostic Procedure"
.
With GST
Follow the procedure “With CONSULT-II” above.
PROCEDURE FOR MALFUNCTION C
With CONSULT-II
1. Turn ignition switch ON and wait at least 1 second.
2. Select “DATA MONITOR” mode with CONSULT-II.
3. Turn ignition switch OFF, wait at least 10 seconds and then turn
ON.
4. Repeat step 3 for 32 times.
5. If 1st trip DTC is detected, go to EC-352, "
Diagnostic Procedure"
.
With GST
Follow the procedure “With CONSULT-II” above.
Diagnostic ProcedureUBS00H70
1. INSPECTION START
With CONSULT-II
1. Turn ignition switch ON.
2. Select “SELF DIAG RESULTS” mode with CONSULT-II.
3. Touch “ERASE”.
4.Perform DTC Confirmation Procedure.
See EC-351, "
DTC Confirmation Procedure" .
5. Is the 1st trip DTC P0605 displayed again?
With GST
1. Turn ignition switch ON.
2. Select MODE 4 with GST.
3. Touch “ERASE”.
4.Perform DTC Confirmation Procedure.
See EC-351, "
DTC Confirmation Procedure" .
5. Is the 1st trip DTC P0605 displayed again?
Ye s o r N o
Yes >> GO TO 2.
No >>INSPECTION END
SEF 0 58 Y
SEF 0 58 Y
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DTC P0605 ECM
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2. REPLACE ECM
1. Replace ECM.
2. Perform initialization of IVIS(NATS) system and registration of all IVIS(NATS) ignition key IDs. Refer to
BL-140, "
ECM Re-communicating Function" .
3. Perform EC-44, "
Accelerator Pedal Released Position Learning" .
4. Perform EC-44, "
Throttle Valve Closed Position Learning" .
5. Perform EC-44, "
Idle Air Volume Learning" .
>>INSPECTION END