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EC-642Revision: October 2005
FUEL PUMP CIRCUIT
2005 QX56
11 . DETECT MALFUNCTIONING PART
Check the following.
Harness connectors E41, C1
Harness for open or short between fuel pump and IPDM E/R
Harness for open or short between fuel pump and ground
>> Repair open circuit or short to ground or short to power in harness or connectors.
12. CHECK FUEL PUMP
Refer to EC-642, "
Component Inspection" .
OK or NG
OK >> GO TO 13.
NG >> Replace “fuel level sensor unit and fuel pump”.
13. CHECK INTERMITTENT INCIDENT
Refer to EC-156, "
TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT" .
OK or NG
OK >> Replace IPDM E/R.
NG >> Repair or replace harness or connectors.
Component InspectionUBS00HDF
FUEL PUMP
1. Disconnect “fuel level sensor unit and fuel pump” harness connector.
2. Check resistance between fuel level sensor unit and fuel pump
terminals 1 and 3.
CONDENSER
1. Turn ignition switch OFF.
2. Disconnect condenser harness connector.
3. Check resistance between condenser terminals as 1 and 2.
Removal and InstallationUBS00HDG
FUEL PUMP
Refer to FL-5, "FUEL LEVEL SENSOR UNIT, FUEL FILTER AND FUEL PUMP ASSEMBLY" . Resistance: 0.2 - 5.0Ω [at 25°C (77°F)]
SEC9 18 C
Resistance Above 1 MΩ at 25°C (77°F)
PBIB0794E
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REFRIGERANT PRESSURE SENSOR
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REFRIGERANT PRESSURE SENSORPFP:92136
Component DescriptionUBS00HDH
The refrigerant pressure sensor is installed at the liquid tank of the
air conditioner system. The sensor uses an electrostatic volume
pressure transducer to convert refrigerant pressure to voltage. The
voltage signal is sent to ECM, and ECM controls cooling fan system.
BBIA0445E
SEF 0 99 XA
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EC-644Revision: October 2005
REFRIGERANT PRESSURE SENSOR
2005 QX56
Wiring DiagramUBS00HDI
BBWA1715E
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REFRIGERANT PRESSURE SENSOR
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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 ProcedureUBS00HDJ
1. CHECK REFRIGERANT PRESSURE SENSOR OVERALL FUNCTION
1. Start engine and warm it up to normal operating temperature.
2. Turn A/C switch and blower switch ON.
3. Check voltage between ECM terminal 70 and ground with CON-
SULT-II or tester.
OK or NG
OK >>INSPECTION END
NG >> GO TO 2.
2. CHECK GROUND CONNECTIONS
1. Turn A/C switch and blower switch OFF.
2. Turn ignition switch OFF.
3. Loosen and retighten three ground screws on the body.
Refer to EC-162, "
Ground Inspection" .
OK or NG
OK >> GO TO 3.
NG >> Repair or replace ground connections.
TER-
MINAL
NO.WIRE
COLORITEM CONDITION DATA (DC Voltage)
49 R/YSensor power supply
(Refrigerant pressure sen-
sor)[Ignition switch: ON]Approximately 5V
67 B Sensor ground[Engine is running]
Warm-up condition
Idle speedApproximately 0V
70 B/W Refrigerant pressure sensor[Engine is running]
Warm-up condition
Both A/C switch and blower switch: ON
(Compressor: Operates)1.0 - 4.0V
Voltage: 1.0 - 4.0V
PBIB11 88 E
BBIA0354E
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EC-646Revision: October 2005
REFRIGERANT PRESSURE SENSOR
2005 QX56
3. CHECK REFRIGERANT PRESSURE SENSOR POWER SUPPLY CIRCUIT
1. Disconnect refrigerant pressure sensor harness connector.
2. Turn ignition switch ON.
3. Check voltage between refrigerant pressure sensor terminal 1
and ground with CONSULT-II or tester.
OK or NG
OK >> GO TO 5.
NG >> GO TO 4.
4. DETECT MALFUNCTIONING PART
Check the following.
Harness connectors E5, F14
Harness for open or short between ECM and refrigerant pressure sensor
>> Repair harness or connectors.
5. CHECK REFRIGERANT PRESSURE SENSOR GROUND CIRCUIT FOR OPEN AND SHORT
1. Turn ignition switch OFF.
2. Disconnect ECM harness connector.
3. Check harness continuity between refrigerant pressure sensor terminal 3 and ECM terminal 67.
Refer to Wiring Diagram.
4. Also check harness for short to ground and short to power.
OK or NG
OK >> GO TO 7.
NG >> GO TO 6.
6. DETECT MALFUNCTIONING PART
Check the following.
Harness connectors E5, F14
Harness for open or short between ECM and refrigerant pressure sensor
>> Repair open circuit or short to ground or short to power in harness or connectors.
BBIA0445E
Voltage: Approximately 5V
PBIB0188E
Continuity should exist.
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REFRIGERANT PRESSURE SENSOR
EC-647
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7. CHECK REFRIGERANT PRESSURE SENSOR INPUT SIGNAL CIRCUIT FOR OPEN AND SHORT
1. Check harness continuity between ECM terminal 70 and refrigerant pressure sensor terminal 2.
Refer to Wiring Diagram.
2. Also check harness for short to ground and short to power.
OK or NG
OK >> GO TO 9.
NG >> GO TO 8.
8. DETECT MALFUNCTIONING PART
Check the following.
Harness connectors E5, F14
Harness for open or short between ECM and refrigerant pressure sensor
>> Repair open circuit or short to ground or short to power in harness or connectors.
9. CHECK INTERMITTENT INCIDENT
Refer to EC-156, "
TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT" .
OK or NG
OK >> Replace refrigerant pressure sensor.
NG >> Repair or replace.
Removal and InstallationUBS00HDK
REFRIGERANT PRESSURE SENSOR
Refer to ATC-185, "Removal and Installation for Refrigerant Pressure Sensor" . Continuity should exist.
Page 1839 of 3419

EC-648Revision: October 2005
ELECTRICAL LOAD SIGNAL
2005 QX56
ELECTRICAL LOAD SIGNALPFP:25350
DescriptionUBS00HDL
The electrical load signal (Headlamp switch signal, rear window defogger switch signal, etc.) is transferred
through the CAN communication line from BCM to ECM via IPDM E/R.
CONSULT-II Reference Value in Data Monitor ModeUBS00HDM
Specification data are reference values.
Diagnostic ProcedureUBS00HDN
1. CHECK LOAD SIGNAL CIRCUIT OVERALL FUNCTION-I
1. Turn ignition switch ON.
2. Connect CONSULT-II and select “DATA MONITOR” mode.
3. Select “LOAD SIGNAL” and check indication under the following
conditions.
OK or NG
OK >> GO TO 2.
NG >> GO TO 3.
2. CHECK LOAD SIGNAL CIRCUIT OVERALL FUNCTION-II
Check “LOAD SIGNAL” indication under the following conditions.
OK or NG
OK >>INSPECTION END
NG >> GO TO 4.
3. CHECK REAR WINDOW DEFOGGER SYSTEM
Refer to GW-77, "
REAR WINDOW DEFOGGER" .
>>INSPECTION END
4. CHECK HEADLAMP SYSTEM
Refer to LT- 6 , "
HEADLAMP (FOR USA)" , or LT- 3 3 , "HEADLAMP (FOR CANADA) - DAYTIME LIGHT SYS-
TEM -" .
>>INSPECTION END
MONITOR ITEM CONDITION SPECIFICATION
LOAD SIGNAL
Ignition switch: ONRear window defogger switch is ON
and/or lighting switch is in 2nd.ON
Rear window defogger switch is OFF
and lighting switch is OFF.OFF
Condition Indication
Rear window defogger switch: ON ON
Rear window defogger switch: OFF OFF
PBIB0103E
Condition Indication
Lighting switch: ON at 2nd position ON
Lighting switch: OFF OFF
PBIB0103E
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ICC BRAKE SWITCH
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ICC BRAKE SWITCHPFP:25320
Component DescriptionUBS00L23
When depress on the brake pedal, ICC brake switch is turned OFF
and stop lamp switch is turned ON. ECM detects the state of the
brake pedal by this input of two kinds (ON/OFF signal)
Refer to ACS-6, "
DESCRIPTION" for the ICC function.
CONSULT-II Reference Value in Data Monitor ModeUBS00L24
Specification data are reference values.
BBIA0470E
MONITOR ITEM CONDITION SPECIFICATION
BRAKE SW 1
(ICC brake switch)
Ignition switch: ONBrake pedal: Fully released ON
Brake pedal: Slightly depressed OFF
BRAKE SW 2
(Stop lamp switch)
Ignition switch: ONBrake pedal: Fully released OFF
Brake pedal: Slightly depressed ON