air condition INFINITI QX56 2011 Factory Service Manual

EC-408
< DTC/CIRCUIT DIAGNOSIS >[VK56VD]
P1421 COLD START CONTROL
P1421 COLD START CONTROL
DescriptionINFOID:0000000006288263
ECM controls ignition timing and engine idle speed when engine is started with prewarming up condition.
This control promotes the activation of three way ca
talyst by heating the catalyst and reduces emissions.
DTC LogicINFOID:0000000006288264
DTC DETECTION LOGIC
NOTE:
If DTC P1421 is displayed with other DTC, firs t perform the trouble diagnosis for other DTC.
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, confirm that battery voltage is more than 11 V at idle.
>> GO TO 2.
2.PERFORM DTC CONFIRMATION PROCEDURE
1. Turn ignition switch OFF and wait at least 10 seconds.
2. Turn ignition switch ON.
3. Select “DATA MONITOR” mode with CONSULT-III.
4. Check the indication of “COOLAN TEMP/S”. If it is between 7 °C (45 °F) and 36 °C (97 °F), go to the following steps.
If it is below 7 °C (45 °F), warm engine up to more than 7 °C (45 °F) and retry from step 1.
If it is above 36 °C (97 °F), cool engine down to less than 36 °C (97 °F) and retry from step 1.
5. Start engine and let it idle for 5 minutes.
6. Check 1st trip DTC.
Is 1st trip DTC detected?
YES >> Go to EC-408, "Diagnosis Procedure".
NO >> INSPECTION END
Diagnosis ProcedureINFOID:0000000006288265
1.PERFORM IDLE AIR VOLUME LEARNING
Perform EC-148, "
Work Procedure".
Is Idle Air Volume Learning carried out successfully?
YES >> GO TO 2.
NO >> Follow the instruction of Idle Air Volume Learning.
2.CHECK INTAKE SYSTEM
Check for the cause of intake air volume lacking. Refer to the following.
 Crushed intake air passage
 Intake air passage clogging
Is the inspection result normal?
YES >> GO TO 3.
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P1421 Cold start emission reduction
strategy monitoring ECM does not control ignition timing and engine
idle speed properly when engine is started with
prewarming up condition.  Lack of intake air volume
 Fuel injection system
ECM
Revision: 2010 May2011 QX56

P1554 BATTERY CURRENT SENSOREC-427
< DTC/CIRCUIT DIAGNOSIS > [VK56VD]
C
D
E
F
G H
I
J
K L
M A
EC
NP
O
1. Check the continuity between battery current
sensor harness connector and ECM harness connector.
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 battery current sensor and ECM
 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 BATTERY CURRENT SENSOR
Refer to EC-427, "
Component Inspection (Battery Current Sensor)".
Is the inspection result normal?
YES >> GO TO 13.
NO >> Replace battery negative cable assembly.
13.CHECK INTERMITTENT INCIDENT
Refer to GI-40, "
Intermittent Incident".
>> INSPECTION END
Component Inspection (B attery Current Sensor)INFOID:0000000006217931
1.CHECK BATTERY CURRENT SENSOR
1. Turn ignition switch OFF.
2. Reconnect harness connectors disconnected.
3. Disconnect battery negative cable.
4. Install jumper cable between battery negative terminal and body ground.
5. Turn ignition switch ON.
6. Check the voltage between ECM harness connector terminals under the following conditions.
Before measuring the terminal voltage, confirm that the battery is fully charged. Refer to PG-159, "How to Handle Battery".
Is the inspection result normal?
YES >> INSPECTION END
NO >> Replace battery negative cable assembly.
Battery current sensor ECM
Continuity
Connector Terminal Connector Terminal
E63 3 E80 138 Existed
: To body ground
ECM Voltage (V)
Connector +–
Te r m i n a l Te r m i n a l
E80 138
(Battery current sensor signal) 150 Approx. 2.5
JPBIA3287ZZ
Revision: 2010 May2011 QX56

EC-432
< DTC/CIRCUIT DIAGNOSIS >[VK56VD]
P1564 ASCD STEERING SWITCH
WITHOUT CONSULT-III
1. Turn ignition switch ON.
2. Check the voltage between ECM harness connector terminals under the following conditions.
Is the inspection result normal?
YES >> GO TO 7.
NO >> GO TO 2.
2.CHECK ASCD STEERING SWITCH GRO UND CIRCUIT FOR OPEN AND SHORT
1. Turn ignition switch OFF.
2. Disconnect ECM harness connector.
3. Disconnect combination switch harness connector.
4. Check the continuity between combination switch and ECM harness connector.
5. Also check harness for short to ground and short to power.
Is the inspection result normal?
YES >> GO TO 4.
NO >> GO TO 3.
3.DETECT MALFUNCTIONING PART
Check the following.
 Combination switch (spiral cable)
 Harness for open and short between ECM and combination switch
>> Repair open circuit, short to ground or short to power in harness or connectors.
4.CHECK ASCD STEERING SWITCH INPUT SI GNAL CIRCUIT FOR OPEN AND SHORT
1. Check the continuity between combination switch and ECM harness connector.
2. Also check harness for short to ground and short to power.
Is the inspection result normal?
YES >> GO TO 6.
NO >> GO TO 5.
SET SW SET/COAST switch Pressed ON
Released OFF
ECM Condition Voltage (V)
Connector +–
Te r m i n a l Te r m i n a l
E80 128
(ASCD steering switch signal) 130MAIN switch: Pressed Approx. 0
CANCEL switch: Pressed Approx. 1
SET/COAST switch: Pressed Approx. 2
RESUME/ACCELERATE switch: Pressed Approx. 3
All ASCD steering switches: Released Approx. 4
Monitor item Condition Indication
Combination switch ECM
Continuity
Connector Terminal Connector Terminal
— 32 E80 130 Existed
Combination switch ECM Continuity
Connector Terminal Connector Terminal
— 25 E80 128 Existed
Revision: 2010 May2011 QX56

P1564 ASCD STEERING SWITCHEC-433
< DTC/CIRCUIT DIAGNOSIS > [VK56VD]
C
D
E
F
G H
I
J
K L
M A
EC
NP
O
5.DETECT MALFUNCTIONING PART
Check the following.
 Combination switch (spiral cable)
 Harness for open and short between ECM and combination switch
>> Repair open circuit, short to ground or short to power in harness or connectors.
6.CHECK ASCD STEERING SWITCH
Refer to EC-433, "
Component Inspection (ASCD Steering Switch)".
Is the inspection result normal?
YES >> GO TO 7.
NO >> Replace ASCD steering switch. Refer to ST-33, "
Removal and Installation".
7.CHECK INTERMITTENT INCIDENT
Refer to GI-40, "
Intermittent Incident".
>> INSPECTION END
Component Inspection (A SCD Steering Switch)INFOID:0000000006217937
1.CHECK ASCD STEERING SWITCH
1. Turn ignition switch OFF.
2. Disconnect combination switch (spiral cable) harness connector M302.
3. Check resistance between combination switch har ness connector terminals under the following condi-
tions.
Is the inspection result normal?
YES >> INSPECTION END
NO >> Replace ASCD steering switch. Refer to ST-33, "
Removal and Installation".
Combination switch
Condition Resistance ( Ω)
Connector Terminals
M302 13 and 16 MAIN switch: Pressed Approx. 0
CANCEL switch: Pressed Approx. 250
SET/COAST switch: Pressed Approx. 660
RESUME/ACCELERATE switch: Pressed Approx. 1,480
All ASCD steering switches: Released Approx. 4,000
Revision: 2010 May2011 QX56

P1564 ICC STEERING SWITCHEC-435
< DTC/CIRCUIT DIAGNOSIS > [VK56VD]
C
D
E
F
G H
I
J
K L
M A
EC
NP
O
Is the inspection result normal?
YES >> GO TO 7.
NO >> GO TO 2.
2.CHECK ICC STEERING SWITCH GRO
UND CIRCUIT FOR OPEN AND SHORT
1. Turn ignition switch OFF.
2. Disconnect ECM harness connector.
3. Disconnect combination switch harness connector.
4. Check the continuity between combination switch and ECM harness connector.
5. Also check harness for short to ground and short to power.
Is the inspection result normal?
YES >> GO TO 4.
NO >> GO TO 3.
3.DETECT MALFUNCTIONING PART
Check the following.
 Combination switch (spiral cable)
 Harness for open and short between ECM and combination switch
>> Repair open circuit, short to ground or short to power in harness or connectors.
4.CHECK ICC STEERING SWITCH INPUT SI GNAL CIRCUIT FOR OPEN AND SHORT
1. Check the continuity between combination switch and ECM harness connector.
2. 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.
 Combination switch (spiral cable)
 Harness for open and short between ECM and combination switch
ECM
Condition Voltage (V)
Connector +–
Te r m i n a l Te r m i n a l
E80 128
(ICC steering switch signal) 130MAIN switch: Pressed Approx. 0
DYNAMIC DRIVER ASSISTANCE switch: Pressed Approx. 1.0
CANCEL switch: Pressed Approx. 1.9
DISTANCE switch: Pressed Approx. 2.6
SET/COAST switch: Pressed Approx. 3.2
RESUME/ACCELERATE switch: Pressed Approx. 3.7
All ICC steering switches: Released Approx. 4.2
Combination switch ECM
Continuity
Connector Terminal Connector Terminal
— 32 E80 130 Existed
Combination switch ECM Continuity
Connector Terminal Connector Terminal
— 25 E80 130 Existed
Revision: 2010 May2011 QX56

EC-436
< DTC/CIRCUIT DIAGNOSIS >[VK56VD]
P1564 ICC STEERING SWITCH
>> Repair open circuit, short to ground or short to power in harness or connectors.
6.CHECK ICC STEERING SWITCH
Refer to EC-436, "
Component Inspection (ICC Steering Switch)".
Is the inspection result normal?
YES >> GO TO 7.
NO >> Replace ICC steering switch. Refer to ST-33, "
Removal and Installation".
7.CHECK INTERMITTENT INCIDENT
Refer to GI-40, "
Intermittent Incident".
>> INSPECTION END
Component Inspection (ICC Steering Switch)INFOID:0000000006217940
1.CHECK ICC STEERING SWITCH
1. Turn ignition switch OFF.
2. Disconnect combination switch (spiral cable) harness connector M302.
3. Check resistance between combination switch harness connector terminals under the following condi-
tions.
Is the inspection result normal?
YES >> INSPECTION END
NO >> Replace ICC steering switch. Refer to ST-33, "
Removal and Installation".
Combination switch
Condition Resistance ( Ω)
Connector Terminals
M302 13 and 16 MAIN switch: Pressed Approx. 0
DYNAMIC DRIVER ASSISTANCE switch: Pressed Approx. 270
CANCEL switch: Pressed Approx. 620
DISTANCE switch: Pressed Approx. 1,100
SET/COAST switch: Pressed Approx. 1,810
RESUME/ACCELERATE switch: Pressed Approx. 3,000
All ICC steering switches: Released Approx. 5,420
Revision: 2010 May2011 QX56

EC-440
< DTC/CIRCUIT DIAGNOSIS >[VK56VD]
P1572 ASCD BRAKE SWITCH
Is the inspection result normal?
YES >> GO TO 13.
NO >> GO TO 8.
3.CHECK ASCD BRAKE SWITCH POWER SUPPLY CIRCUIT
1. Turn ignition switch OFF.
2. Disconnect ASCD brake switch harness connector.
3. Turn ignition switch ON.
4. Check the voltage between ASCD brake switch harness connector and ground.
Is the inspection result normal?
YES >> GO TO 5.
NO >> GO TO 4.
4.DETECT MALFUNCTIONING PART
Check the following.
 10 A fuse (No. 3)
 Harness for open or short between ASCD brake switch and fuse
 Loose or poor connection for each connector and harness
>> Repair open circuit or short to ground in harness or connectors.
5.CHECK ASCD BRAKE SWITCH INPUT SIGNAL CIRCUIT FOR OPEN AND SHORT
1. Turn ignition switch OFF.
2. Disconnect ECM harness connector.
3. Check the continuity between ASCD brake 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 7.
NO >> GO TO 6.
6.DETECT MALFUNCTIONING PART
Check the following.
 Harness for open or short between ECM and ASCD brake switch
 Loose or poor connection for each connector and harness
>> Repair open circuit, short to ground or short to power in harness or connectors.
7.CHECK ASCD BRAKE SWITCH
Refer to EC-442, "
Component Inspection (ASCD Brake Switch)"
Is the inspection result normal?
ECM
Condition Voltage (V)
Connector +–
Terminal Terminal
E80 158
(Stop lamp switch signal) 175 Brake pedalSlightly depressed Battery voltage
Fully released Approx. 0
ASCD brake switch
Ground Voltage
Connector Terminal
E109 1 Ground Battery voltage
ASCD brake switch ECM Continuity
Connector Terminal Connector Terminal
E109 2 E80 147 Existed
Revision: 2010 May2011 QX56

P1572 ICC BRAKE SWITCHEC-445
< DTC/CIRCUIT DIAGNOSIS > [VK56VD]
C
D
E
F
G H
I
J
K L
M A
EC
NP
O
Is the inspection result normal?
YES >> GO TO 5.
NO >> GO TO 4.
4.DETECT MALFUNCTIONING PART
Check the following.
 10 A fuse (No. 3)
 Harness for open or short between ICC brake switch and fuse
 Loose or poor connection for each connector and harness
>> Repair open circuit or short to ground in harness or connectors.
5.CHECK ICC BRAKE SWITCH INPUT SIGN AL CIRCUIT FOR OPEN AND SHORT
1. Turn ignition switch OFF.
2. Disconnect ECM harness connector.
3. Check the continuity between ICC brake sw itch 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 7.
NO >> GO TO 6.
6.DETECT MALFUNCTIONING PART
Check the following.
 Harness for open or short between ICC brake switch and ECM
 Loose or poor connection for each connector and harness
>> Repair open circuit, short to ground or short to power in harness or connectors.
7.CHECK ICC BRAKE SWITCH
Refer to EC-445, "
Component Inspection (ICC Brake Switch)".
Is the inspection result normal?
YES >> GO TO 8.
NO >> Replace ICC brake switch.
8.CHECK INTERMITTENT INCIDENT
Refer to GI-40, "
Intermittent Incident".
>> INSPECTION END
Component Inspection (ICC Brake Switch)INFOID:0000000006217949
1.CHECK ICC BRAKE SWITCH-I
1. Turn ignition switch OFF.
2. Disconnect ICC brake switch harness connector.
3. Check the continuity between ICC brake switch terminals under the following conditions.
Is the inspection result normal?
YES >> INSPECTION END
ICC brake switch ECM Continuity
Connector Terminal Connector Terminal
E68 2 E80 147 Existed
Terminals Condition Continuity
1 and 2 Brake pedal Fully released Existed
Slightly depressed Not existed
Revision: 2010 May2011 QX56

P1805 BRAKE SWITCHEC-455
< DTC/CIRCUIT DIAGNOSIS > [VK56VD]
C
D
E
F
G H
I
J
K L
M A
EC
NP
O
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