2011 INFINITI QX56 air condition

P1805 BRAKE SWITCHEC-455
< DTC/CIRCUIT DIAGNOSIS > [VK56VD]
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P1805 BRAKE SWITCH
DTC LogicINFOID:0000000006217957
DTC DETECTION LOGIC
DTC CONFIRMATION PROCEDURE
1.PERFORM DTC CONFIRMATION PROCEDURE
1. Turn ignition switch ON.
2. Fully depress the brake pedal for at least 5 seconds.
3. Erase the DTC.
4. Check 1st trip DTC.
Is 1st trip DTC detected?
YES >> Go to EC-455, "Diagnosis Procedure".
NO >> INSPECTION END
Diagnosis ProcedureINFOID:0000000006217958
1.CHECK STOP LAMP SWITCH CIRCUIT
1. Turn ignition switch OFF.
2. Check for stop lamp illumination under the following conditions.
Is the inspection result normal?
YES >> GO TO 4.
NO >> GO TO 2.
2.CHECK STOP LAMP SWIT CH POWER SUPPLY CIRCUIT
1. Disconnect stop lamp switch harness connector.
2. Check the voltage between stop lamp switch harness connector and ground.
Is the inspection result normal?
YES >> GO TO 4.
NO >> GO TO 3.
3.DETECT MALFUNCTIONING PART
Check the following.
 10 A fuse (No. 7)
 Harness for open or short between stop lamp switch and battery
 Loose or poor connection for each connector and harness
>> Repair open circuit, short to ground or short to power in harness or connectors.
DTC No. Trouble diagnosis name
(Trouble diagnosis content) DTC detecting condition Possible cause
P1805 BRAKE SW/CIRCUIT
(Brake switch) A brake switch signal is not sent to ECM
for extremely long time while the vehicle
is being driven.  Harness or connectors
(Stop lamp switch circuit is open or shorted.)
 Stop lamp switch
Condition Stop lamp
Brake pedal Fully released Not illuminated
Slightly depressed Illuminated
Stop lamp switch Ground Voltage
Connector Terminal
E115 1 Ground Battery voltage
Revision: 2010 May2011 QX56

EC-456
< DTC/CIRCUIT DIAGNOSIS >[VK56VD]
P1805 BRAKE SWITCH
4.CHECK STOP LAMP SWITCH INPUT SIGNAL CIRCUIT FOR OPEN AND SHORT
1. Disconnect stop lamp switch harness connector.
2. Disconnect ECM harness connector.
3. Check the continuity between stop lamp s witch harness connector and ECM harness connector.
4. Also check harness for short to ground and short to power.
Is the inspection result normal?
YES >> GO TO 6.
NO >> GO TO 5.
5.DETECT MALFUNCTIONING PART
Check the following.
 Harness for open or short between ECM and stop lamp switch
 Loose or poor connection for each connector and harness
>> Repair open circuit, short to ground or short to power in harness or connectors.
6.CHECK STOP LAMP SWITCH
Refer to EC-456, "
Component Inspection (Stop Lamp Switch)".
Is the inspection result normal?
YES >> GO TO 7.
NO >> Replace stop lamp switch. Refer to BR-20, "
Removal and Installation".
7.CHECK INTERMITTENT INCIDENT
Refer to GI-40, "
Intermittent Incident".
>> INSPECTION END
Component Inspection (Stop Lamp Switch)INFOID:0000000006217959
1.CHECK STOP LAMP SWITCH-I
1. Turn ignition switch OFF.
2. Disconnect stop lamp switch harness connector.
3. Check the continuity between stop lamp switch terminals under the following conditions.
Is the inspection result normal?
YES >> INSPECTION END
NO >> GO TO 2.
2.CHECK STOP LAMP SWITCH-II
1. Adjust stop lamp switch installation. Refer to BR-21, "
Inspection and Adjustment".
2. Check the continuity between stop lamp switch terminals under the following conditions.
Is the inspection result normal?
Stop lamp switch ECM Continuity
Connector Terminal Connector Terminal
E115 2 E80 158 Existed
Terminals Condition Continuity
1 and 2 Brake pedal Fully released Not existed
Slightly depressed Existed
Terminals Condition Continuity
1 and 2 Brake pedal Fully released Not existed
Slightly depressed Existed
Revision: 2010 May2011 QX56

EC-464
< DTC/CIRCUIT DIAGNOSIS >[VK56VD]
P2118 THROTTLE CONTROL MOTOR
P2118 THROTTLE CONTROL MOTOR
DTC LogicINFOID:0000000006217967
DTC DETECTION LOGIC
DTC CONFIRMATION PROCEDURE
1.PRECONDITIONING
If DTC Confirmation Procedure has been previously conduc ted, always turn ignition switch OFF and wait at
least 10 seconds before conducting the next test.
>> GO TO 2.
2.PERFORM DTC CONFIRMATION PROCEDURE
1. Turn ignition switch ON and wait at least 2 seconds.
2. Start engine and let it idle for 5 seconds.
3. Check DTC.
Is DTC detected?
YES >> Go to EC-464, "DTC Logic".
NO >> INSPECTION END
Diagnosis ProcedureINFOID:0000000006217968
1.CHECK THROTTLE CONTROL MOTOR OUTPUT SIGNAL CIRCUIT FOR OPEN AND SHORT
1. Disconnect electric throttle control actuator harness connector.
2. Disconnect ECM harness connector.
3. Check the continuity between electric throttle control actuator harness connector and ECM harness con-
nector.
4. Also check harness for short to ground and short to power.
Is the inspection result normal?
YES >> GO TO 2.
NO >> Repair or replace malfunctioning part.
2.CHECK THROTTLE CONTROL MOTOR
Refer to EC-465, "
Component Inspection (Electric Throttle Control Motor)".
Is the inspection result normal?
YES >> GO TO 3.
NO >> GO TO 4.
3.CHECK INTERMITTENT INCIDENT
DTC No. Trouble diagnosis name
(Trouble diagnosis content) DTC detecting condition Possible cause
P2118 ETC MOT-B1
(Throttle control motor circuit
short) ECM detects short in both circuits between
ECM and throttle control motor.  Harness or connectors
(Throttle control motor circuit is shorted.)
 Electric throttle control actuator
(Throttle control motor)
Electric throttle control actuator ECM Continuity
Connector Terminal Connector Terminal
F66 5
F110 57 Not existed
63 Existed
6 57 Existed
63 Not existed
Revision: 2010 May2011 QX56

EC-466
< DTC/CIRCUIT DIAGNOSIS >[VK56VD]
P2119 ELECTRIC THROTTLE CONTROL ACTUATOR
P2119 ELECTRIC THROTTLE CONTROL ACTUATOR
DTC LogicINFOID:0000000006217970
DTC DETECTION LOGIC
DTC CONFIRMATION PROCEDURE
1.PRECONDITIONING
If DTC Confirmation Procedure has been previously conduc ted, always turn ignition switch OFF and wait at
least 10 seconds before conducting the next test.
>> GO TO 2.
2.PERFORM DTC CONFIRMATION PROC EDURE FOR MALFUNCTION A AND B
1. Turn ignition switch ON and wait at least 1 second.
2. Selector lever position is D and wait at least 3 seconds.
3. Selector lever position is P.
4. Turn ignition switch OFF and wait at least 10 seconds.
5. Turn ignition switch ON and wait at least 1 second.
6. Selector lever position is D and wait at least 3 seconds.
7. Selector lever position is P.
8. Turn ignition switch OFF, wait at least 10 seconds, and then turn ON.
9. Check DTC.
Is DTC detected?
YES >> Go to EC-466, "Diagnosis Procedure".
NO >> GO TO 3.
3.PERFORM DTC CONFIRMATION PROCEDURE FOR MALFUNCTION C
1. Turn ignition switch ON and wait at least 1 second.
2. Selector lever position is D and wait at least 3 seconds.
3. Selector lever position is N or P.
4. Start engine and let it idle for 3 seconds.
5. Check DTC.
Is DTC detected?
YES >> Go to EC-466, "Diagnosis Procedure".
NO >> INSPECTION END
Diagnosis ProcedureINFOID:0000000006217971
1.CHECK ELECTRIC THROTTLE CONTROL ACTUATOR VISUALLY
1. Turn ignition switch OFF.
2. Remove the intake air duct.
3. Check if foreign matter is caught between the throttle valve and the housing.
Is the inspection result normal?
YES >> GO TO 2.
DTC No. Trouble diagnosis name
(Trouble diagnosis content) DTC detecting condition Possible cause
P2119 ETC ACTR-B1
(Electric throttle control actuator) A)
Electric throttle control actuator does not
function properly due to the return spring
malfunction.
 Electric throttle control actuator
B) Throttle valve opening angle in fail-safe
mode is not in specified range.
C) ECM detects that the throttle valve is stuck
open.
Revision: 2010 May2011 QX56

P2135 TP SENSOREC-475
< DTC/CIRCUIT DIAGNOSIS > [VK56VD]
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P2135 TP SENSOR
DTC LogicINFOID:0000000006217978
DTC DETECTION LOGIC
NOTE:
If DTC P2135 is displayed with DTC P0643, perfo
rm the trouble diagnosis for DTC P0643. Refer to EC-
381, "DTC Logic".
DTC CONFIRMATION PROCEDURE
1.PRECONDITIONING
1. Turn ignition switch OFF and wait at least 10 seconds.
2. Turn ignition switch ON.
3. Turn ignition switch OFF and wait at least 10 seconds.
TESTING CONDITION:
Before performing the following procedure, confi rm that battery voltage is 8 V or more at idle.
>> GO TO 2.
2.PERFORM DTC CONFIRMATION PROCEDURE
1. Start engine and let it idle for 1 second.
2. Check DTC.
Is DTC detected?
YES >> Go to EC-475, "Diagnosis Procedure".
NO >> INSPECTION END
Diagnosis ProcedureINFOID:0000000006217979
1.CHECK THROTTLE POSITION SEN SOR POWER SUPPLY CIRCUIT-I
1. Disconnect electric throttle c ontrol actuator harness connector.
2. Turn ignition switch ON.
3. Check the voltage between electric throttle control actuator harness connector and ground.
Is the inspection result normal?
YES >> GO TO 2.
NO >> Repair open circuit, short to ground or short to power in harness or connectors.
2.CHECK THROTTLE POSITI ON SENSOR GROUND CIRCUIT FOR OPEN AND SHORT
1. Turn ignition switch OFF.
2. Disconnect ECM harness connector.
3. Check the continuity between electric throttle control actuator harness connector and ECM harness con-
nector.
DTC No. Trouble diagnosis name
(Trouble diagnosis content) DTC detecting condition Possible cause
P2135 TP SENSOR-B1
(Throttle position sensor circuit
range/performance) Rationally incorrect voltage is sent to
ECM compared with the signals from
TP sensor 1 and TP sensor 2.  Harness or connector
(TP sensor 1 or 2 circuit is open or shorted.)
 Electric throttle control actuator
(TP sensor 1 or 2)
Electric throttle control actuator Ground Voltage (V)
Connector Terminal
F66 2 Ground Approx. 5
Revision: 2010 May2011 QX56

EC-476
< DTC/CIRCUIT DIAGNOSIS >[VK56VD]
P2135 TP SENSOR
4. Also check harness for short to ground and short to power.
Is the inspection result normal?
YES >> GO TO 3.
NO >> Repair open circuit, short to ground or short to power in harness or connectors.
3.CHECK THROTTLE POSITION
SENSOR INPUT SIGNAL CIRCUIT FOR OPEN AND SHORT
1. Check the continuity between electric throttle control actuator harness connector and ECM harness con-
nector.
2. Also check harness for short to ground and short to power.
Is the inspection result normal?
YES >> GO TO 4.
NO >> Repair open circuit, short to ground or short to power in harness or connectors.
4.CHECK THROTTLE POSITION SENSOR
Refer to EC-476, "
Component Inspection (Throttle Position Sensor)".
Is the inspection result normal?
YES >> GO TO 6.
NO >> GO TO 5.
5.REPLACE ELECTRIC THROTTLE CONTROL ACTUATOR
Replace electric throttle control actuator. Refer to EM-30, "
Removal and Installation".
>> INSPECTION END
6.CHECK INTERMITTENT INCIDENT
Refer to GI-40, "
Intermittent Incident".
>> INSPECTION END
Component Inspection (Throttle Position Sensor)INFOID:0000000006217980
1.CHECK THROTTLE POSITION SENSOR
1. Turn ignition switch OFF.
2. Reconnect all harness connectors disconnected.
3. Perform EC-147, "
Work Procedure".
4. Turn ignition switch ON.
5. Set selector lever position to D.
6. Check the voltage between ECM harness connector terminals under the following conditions.
Electric throttle control actuator ECM Continuity
Connector Terminal Connector Terminal
F66 4 F110 97 Existed
Electric throttle control actuator ECM Continuity
Connector Terminal Connector Terminal
F66 1
F110 91
Existed
379
Revision: 2010 May2011 QX56

P2138 APP SENSOREC-481
< DTC/CIRCUIT DIAGNOSIS > [VK56VD]
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2. Also check harness for short to ground and short to power.
Is the inspection result normal?
YES >> GO TO 12.
NO >> GO TO 11.
11 .DETECT MALFUNCTIONING PART
Check the following.
 Harness for open or short between ECM and accelerator pedal position sensor
 Loose or poor connection for each connector and harness
>> Repair open circuit, short to ground or short to power in harness or connectors.
12.CHECK APP SENSOR
Refer to EC-481, "
Component Inspection (Accelerator Pedal Position Sensor)".
Is the inspection result normal?
YES >> GO TO 14.
NO >> GO TO 13.
13.REPLACE ACCELERATOR PEDAL ASSEMBLY
Replace accelerator pedal assembly. Refer to ACC-3, "
MODELS WITHOUT DISTANCE CONTROL ASSIST
SYSTEM : Removal and Installation" (Without distance control assist system) or ACC-4, "MODELS WITH
DISTANCE CONTROL ASSIST SYSTEM : Removal and Installation" (With distance control assist system).
>> INSPECTION END
14.CHECK INTERMITTENT INCIDENT
Refer to GI-40, "
Intermittent Incident".
>> INSPECTION END
Component Inspection (Accele rator Pedal Position Sensor)INFOID:0000000006217983
1.CHECK ACCELERATOR PEDAL POSITION SENSOR
1. Turn ignition switch OFF.
2. Reconnect all harness connectors disconnected.
3. Turn ignition switch ON.
4. Check the voltage ECM harness connector terminals under the following conditions.
Is the inspection result normal?
APP sensor ECM Continuity
Connector Terminal Connector Terminal
E110
(Without ICC) 3
E80 136
Existed
6126
E67
(With ICC) 10
E80 136
Existed
7126
ECM
Condition Voltage (V)
Connector +–
Te r m i n a l Te r m i n a l
E80 136 (APP sensor 1) 140
Accelerator pedalFully released 0.65 - 0.87
Fully depressed 4.3 - 4.8
126 (APP sensor 2) 129 Fully released 0.28 - 0.48
Fully depressed 2.0 - 2.5
Revision: 2010 May2011 QX56

P2539, P2541, P2542 LOW FUEL PRESSURE SENSOR
EC-485
< DTC/CIRCUIT DIAGNOSIS > [VK56VD]
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NO >> Repair or replace error-detected parts.
6.CHECK LOW FUEL PRESSURE SENSOR SIGNAL CIRCUIT
1. Turn ignition switch OFF.
2. Disconnect ECM harness connector.
3. Check the continuity between low fuel pressu re sensor harness connector and ECM harness connector.
4. Also check harness for short to ground and to power.
Is inspection result normal?
YES >> GO TO 7.
NO >> Repair or replace error-detected parts.
7.CHECK LOW FUEL PRESSURE SENSOR
Refer to EC-485, "
Component Inspection".
Is inspection result normal?
YES >> Check intermittent incident. Refer to GI-40, "Intermittent Incident".
NO >> Replace low fuel pressure sensor.
Component InspectionINFOID:0000000006289706
1.CHECK LOW FUEL PRESSURE SENSOR
WITH CONSULT-III
1. Turn ignition switch OFF.
2. Reconnect harness connector disconnected.
3. Start the engine.
4. Select “DATA MONITOR” mode with CONSULT-III.
5. Check that the “L/FUEL PRES SEN V” value.
WITHOUT CONSULT-III
1. Turn ignition switch OFF.
2. Reconnect harness connector disconnected.
3. Start the engine.
4. Check low fuel pressure sensor signal voltage.
+ −
Continuity
Low fuel pressure sensor ECM
Connector Terminal Connector Terminal F25 2 F111 23 Existed
Data monitor item Condition Va l u e
(Approx.)
L/FUEL PRES SEN V Engine speed: idle
3,000 –3,300 mV
Engine speed: 3,000 rpm (no load)
Revision: 2010 May2011 QX56