2009 INFINITI QX56 engine

EC-298
< COMPONENT DIAGNOSIS >[VK56DE]
P1217 ENGINE OVER TEMPERATURE
P1217 ENGINE OVER TEMPERATURE
On Board Diagn
osis LogicINFOID:0000000003771589
NOTE:
If DTC P1217 is displayed with DTC U1000 or U1001, first perform the trouble diagnosis for DTC
U1000, U1001. Refer to EC-86
.
 If DTC P1217 is displayed with DTC P0607, first pe rform the trouble diagnosis for DTC P0607. Refer
to EC-284
.
If the cooling fan or another component in the coo ling system malfunctions, engine coolant temperature will
rise.
When the engine coolant temperature reaches an abnorma lly high temperature condition, a malfunction is
indicated.
This self-diagnosis has the one trip detection logic.
CAUTION:
When a malfunction is indicated, be su re to replace the coolant. Refer to CO-11, "Changing Engine
Coolant". Also, replace the engine oil. Refer to LU-9, "Changing Engine Oil".
1. Fill radiator with coolant up to specified level with a filling speed of 2 liters per minute. Be sure to
use coolant with the proper mixture ratio. Refer to CO-10
.
2. After refilling coolant, run engine to en sure that no water-flow noise is emitted.
Overall Function CheckINFOID:0000000003771590
Use this procedure to check the overall function of the cooling fan. During this check, a DTC might not be con-
firmed.
WARNING:
Never remove the radiator cap and/or reservoir tank cap when the engine is hot. Serious burns could
be caused by high pressure fluid escaping fr om the radiator and/or reservoir tank.
Wrap a thick cloth around cap. Carefully remove the cap by turning it a quarter turn to allow built-up
pressure to escape. Then turn the cap all the way off.
WITH CONSULT-III
1. Check the coolant level in the reservoir tank and radiator. Allow engine to cool before checking coolant level.
If the coolant level in the reservoir tank and/or radiator is below
the proper range, skip the following steps and go to EC-388,
"Diagnosis Procedure".
2. Confirm whether customer filled the coolant or not. If customer
filled the coolant, skip the following steps and go to EC-388,
"Diagnosis Procedure".
3. Turn ignition switch ON.
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P1217
1217 Engine over tempera-
ture (Overheat)  Cooling fan does not operate properly (Over-
heat).
 Cooling fan system does not operate proper-
ly (Overheat).
 Engine coolant was not added to the system using the proper filling method.
 Engine coolant is not within the specified range.  Harness or connectors
(The cooling fan circuit is open or short-
ed.)
 Cooling fan
 Cooling fan (crankshaft diven)
 IPDM E/R (Cooling fan relay)
Radiator hose
Radiator
Radiator cap
 Reservoir tank
 Reservoir tank cap
 Water pump
Thermostat
For more informat ion, refer to EC-300,
"Main 13 Causes of Overheating".
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P1217 ENGINE OVER TEMPERATUREEC-299
< COMPONENT DIAGNOSIS > [VK56DE]
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4. Perform “COOLING FAN” in “ACTIVE TEST” mode with CONSULT-III.
5. If the results are NG, go to
EC-388, "Diagnosis Procedure"
.
WITH GST
1. Check the coolant level in the reservoir tank and radiator.
Allow engine to cool befo re checking coolant level.
If the coolant level in the reservoir tank and/or radiator is below
the proper range, skip the following steps and go to EC-388,
"Diagnosis Procedure".
2. Confirm whether customer filled the coolant or not. If customer
filled the coolant, skip the following steps and go to EC-388,
"Diagnosis Procedure".
3. Disconnect engine coolant temper ature sensor harness connec-
tor.
4. Connect 150 Ω resistor to engine coolant temperature sensor
harness connector.
5. Start engine and make sure that cooling fan operates. CAUTION:
Be careful not to overheat engine.
6. If NG, go to EC-388, "Diagnosis Procedure"
.
Diagnosis ProcedureINFOID:0000000003771591
1.CHECK COOLING FAN (CRANKSHAFT DRIVEN) OPERATION
1. Start engine and let it idle.
2. Make sure that cooling fan (crankshaft driven) operates normally.
OK or NG
OK (With CONSULT-III)>>GO TO 2.
OK (Without CONSULT-III)>>GO TO 3.
NG >> Check cooling fan (crankshaft driven). Refer to CO-18, "Removal and Installation (Crankshaft
Driven Type)".
2.CHECK COOLING FAN MOTOR OPERATION
With CONSULT-III
1. Start engine and let it idle.
2. Select “COOLING FAN” in “A CTIVE TEST” mode with CONSULT-III.
3. Make sure that cooling fan operates.
OK or NG
OK >> GO TO 4.
NG >> Check cooling fan control ci rcuit. (Go to "PROCEDURE A".)
3.CHECK COOLING FAN MOTOR OPERATION
Without CONSULT-III
1. Disconnect engine coolant temperature sensor harness connector.
2. Connect 150 Ω resistor to engine coolant temperature sensor harness connector.
3. Start engine and let it idle.
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SEF882V
Revision: December 20092009 QX56

EC-300
< COMPONENT DIAGNOSIS >[VK56DE]
P1217 ENGINE OVER TEMPERATURE
4. Make sure that cooling fan operates.
OK or NG
OK >> GO TO 4.
NG >> Check cooling fan control circuit. (Go to "PROCEDURE
A".)
4.CHECK COOLING SYSTEM FOR LEAK
Refer to CO-10, "Inspection"
.
OK or NG
OK >> GO TO 5.
NG >> Check the following for leak. Hose
 Radiator
 Radiator cap
 Water pump
 Reservoir tank
5.CHECK COMPONENT PARTS
Check the following.
 RESERVOIR TANK CAP (Refer to CO-10, "Inspection"
.)
 Thermostat. (Refer to CO-22, "Removal and Installation"
.)
 Engine coolant temperature sensor. (Refer to EC-122, "Component Inspection"
.)
OK or NG
OK >> GO TO 7.
NG >> Replace malfunctioning component.
6.CHECK MAIN 13 CAUSES
If the cause cannot be isolated, go to EC-300, "Main 13 Causes of Overheating"
.
>> INSPECTION END
Main 13 Causes of OverheatingINFOID:0000000003771592
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Engine Step Inspection item Equipment Standard Reference page
OFF 1  Blocked radiator  Blocked condenser
 Blocked radiator grille
 Blocked bumper  Visual No blocking —
2  Coolant mixture  Coolant tester 50 - 50% coolant mixture CO-10
3  Coolant level  Visual Coolant up to MAX level in
reservoir tank and radiator
filler neckCO-11, "Changing Engine
Coolant"
4  Reservoir tank cap  Pre
ssure tester 95 - 125 kPa
(0.97 - 1.28 kg/cm2, 14 -
18 psi) (Limit) CO-10, "Inspection"
ON*25  Coolant leaks  Visual No leaks
CO-10, "Inspection"
ON*26  Thermostat  Touch the upper and
lower radiator hosesBoth hoses should be hot
CO-22, "Removal and In-
stallation"
ON*17  Cooling fan  CONSULT-III Operating See trouble diagnosis for
DTC P1217 (EC-36
).
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P1217 ENGINE OVER TEMPERATUREEC-301
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*1: Turn the ignition switch ON.
*2: Engine running at 3,000 rpm for 10 minutes.
*3: Drive at 90 km/h (55 MPH) for 30 minutes and then let idle for 10 minutes.
*4: After 60 minutes of cool down time.
For more information, refer to
CO-8, "Troubleshooting Chart"
.
OFF 8  Combustion gas leak  Color checker chemical
tester 4 Gas analyzerNegative —
ON*
39  Coolant temperature gauge  Visual Gauge less than 3/4 when
driving —
 Coolant overflow to res- ervoir tank  Visual No overflow during driving
and idling CO-11, "Changing Engine
Coolant"
OFF*410  Coolant return from res-
ervoir tank to radiator  Visual Should be initial level in
reservoir tank CO-11, "Changing Engine
Coolant"
OFF 12  Cylinder head  Straight gauge feeler
gauge0.1 mm (0.004 in) Maxi-
mum distortion (warping) EM-72, "Inspection After
Disassembly"
13  Cylinder block and pis-
tons  Visual No scuffing on cylinder
walls or piston EM-90, "Inspection After
Disassembly"
Engine Step Inspection item Equipment Standard Reference page
Revision: December 20092009 QX56

EC-306
< COMPONENT DIAGNOSIS >[VK56DE]
P1421 COLD START CONTROL
P1421 COLD START CONTROL
DescriptionINFOID:0000000003771601
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.
On Board Diagnosis LogicINFOID:0000000003771602
DTC Confirmation ProcedureINFOID:0000000003771603
NOTE:
 If DTC Confirmation Procedure has been previously conducted, always perform the following before con-
ducting the next step.
1. Turn ignition swich OFF and wait at least 10 seconds.
2. Turn ignition swich ON.
3. Turn ignition swich OFF and wait at least 10 seconds.
 If DTC P1421 is displayed with other DTC, firs t perform the trouble diagnosis for other DTC.
TESTING CONDITION:
Before performing the following procedure, confirm that battery voltage is more than 11V at idle.
1. Turn ignition switch OFF and wait at least 10 seconds.
2. Turn ignition switch ON.
3. Select “DATA MONITOR” mode with CONSULT-IIl.
4. Check that the “COOLAN TEMP/S” indication is between 4 °C (39 °F) and 36 °C (97 °F).
If “COOLAN TEMP/S” indication is within t he specified value, go to the following step.
If “COOLANT TEMP/S” indication is out of the s pecified value, cool engine down or warm engine up and
go to step 1.
5. Start engine and let it idle for 5 minutes.
6. Check 1st trip DTC.
7. If 1st trip DTC is detected, go to EC-306, "Diagnosis Procedure"
.
Diagnosis ProcedureINFOID:0000000003771604
1.PERFORM IDLE AIR VOLUME LEARNING
Perform EC-18, "Idle Air Volume Learning"
.
Is Idle Air Volume Lear ning carried out successfully?
Ye s o r N o
Ye s > > G O T O 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
OK or NG
OK >> GO TO 3.
NG >> Repair or replace malfunctioning part
3.CHECK FUEL INJECTION SYSTEM FUNCTION
Perform EC-169, "DTC Confirmation Procedure"
in DTC P0171, P0174 FUEL INJECTION SYSTEM FUNC-
TION.
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P1421
1421 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: December 20092009 QX56

EC-308
< COMPONENT DIAGNOSIS >[VK56DE]
P1550 BATTERY CURRENT SENSOR
P1550 BATTERY CURRENT SENSOR
Component DescriptionINFOID:0000000003771605
The power generation voltage variable control enables fuel con-
sumption to be decreased by reducing the engine load which is
caused by the power generation of the generator. The battery cur-
rent sensor (1) is installed to the battery cable at the negative termi-
nal. The sensor measures the charging/discharging current of the
battery. Based on the sensor signal, ECM judges whether or not the
power generation voltage variable control is performed. When per-
forming the power generation voltage variable control, ECM calcu-
lates the target power generation voltage based on the sensor
signal. And ECM sends the calculated value as the power genera-
tion command value to IPDM E/R. For the details of the power gen-
eration voltage variable control, refer to
CHG-7, "System
Description".
: Vehicle front
CAUTION:
Do not connect the electrical compon ent or the ground wire directly to the battery terminal. The con-
nection causes the malfunction of th e power generation voltage variable control, and then the battery
discharge may occur.
On Board Diagn osis LogicINFOID:0000000003771606
The MIL will not light up for this self-diagnosis.
NOTE:
If DTC P1550 is displayed with DTC P0643, first pe rform the trouble diagnosis for DTC P0643. Refer to
EC-285
.
DTC Confirmation ProcedureINFOID:0000000003771607
If DTC Confirmation Procedure has been previously conducted, always perform the following before conduct-
ing the next step.
1. Turn ignition swich OFF and wait at least 10 seconds.
2. Turn ignition swich ON.
3. Turn ignition swich OFF and wait at least 10 seconds.
TESTING CONDITION:
Before performing the following procedure, confirm that battery voltage is more than 8V at idle.
1. Start engine and wait at least 10 seconds.
2. Check 1st trip DTC.
3. If 1st trip DTC is detected, go to EC-308, "Diagnosis Procedure"
.
Diagnosis ProcedureINFOID:0000000003771608
1.CHECK GROUND CONNECTIONS
1. Turn ignition switch OFF.
2. Loosen and retighten ground screws on the body.
BBIA0744E
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P1550
1550 Battery current sensor circuit
range/performance The output voltage of the battery current
sensor remains within the specified
range while engine is running.  Harness or connectors
(The sensor circuit is open or shorted.)
 Battery current sensor
Revision: December 20092009 QX56

EC-312
< COMPONENT DIAGNOSIS >[VK56DE]
P1551, P1552 BATTERY CURRENT SENSOR
P1551, P1552 BATTERY CURRENT SENSOR
Component DescriptionINFOID:0000000003771610
The power generation voltage variable control enables fuel con-
sumption to be decreased by reducing the engine load which is
caused by the power generation of the generator. The battery cur-
rent sensor (1) is installed to the battery cable at the negative termi-
nal. The sensor measures the charging/discharging current of the
battery. Based on the sensor signal, ECM judges whether or not the
power generation voltage variable control is performed. When per-
forming the power generation voltage variable control, ECM calcu-
lates the target power generation voltage based on the sensor
signal. And ECM sends the calculated value as the power genera-
tion command value to IPDM E/R. For the details of the power gen-
eration voltage variable control, refer to
CHG-7, "System
Description".
: Vehicle front
CAUTION:
Do not connect the electrical compon ent or the ground wire directly to the battery terminal. The con-
nection causes the malfunction of th e power generation voltage variable control, and then the battery
discharge may occur.
On Board Diagn osis LogicINFOID:0000000003771611
The MIL will not light up for these self-diagnoses.
NOTE:
If DTC P1551 or P1552 is displayed with DTC P0643, first perform the trouble diagnosis for DTC P0643.
Refer to EC-285, "On Board Diagnosis Logic"
.
DTC Confirmation ProcedureINFOID:0000000003771612
If DTC Confirmation Procedure has been previously conducted, always perform the following before conduct-
ing the next step.
1. Turn ignition swich OFF and wait at least 10 seconds.
2. Turn ignition swich ON.
3. Turn ignition swich OFF and wait at least 10 seconds.
TESTING CONDITION:
Before performing the following procedure, confirm th at battery voltage is more than 8V with ignition
switch ON
1. Turn ignition switch ON.
2. Wait at least 10 seconds.
3. Check 1st trip DTC.
4. If 1st trip DTC is detected, go to EC-312, "Diagnosis Procedure"
.
Diagnosis ProcedureINFOID:0000000003771613
1.CHECK GROUND CONNECTIONS
1. Turn ignition switch OFF.
2. Loosen and retighten ground screws on the body.
BBIA0744E
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P1551
1551 Battery current sensor circuit
low input An excessively low voltage from the sensor
is sent to ECM.
 Harness or connectors
(The sensor circuit is open or shorted.)
 Battery current sensor
P1552
1552 Battery current sensor circuit
high input An excessively high voltage from the sensor
is sent to ECM.
Revision: December 20092009 QX56

EC-316
< COMPONENT DIAGNOSIS >[VK56DE]
P1553 BATTERY CURRENT SENSOR
P1553 BATTERY CURRENT SENSOR
Component DescriptionINFOID:0000000003771615
The power generation voltage variable control enables fuel con-
sumption to be decreased by reducing the engine load which is
caused by the power generation of the generator. The battery cur-
rent sensor (1) is installed to the battery cable at the negative termi-
nal. The sensor measures the charging/discharging current of the
battery. Based on the sensor signal, ECM judges whether or not the
power generation voltage variable control is performed. When per-
forming the power generation voltage variable control, ECM calcu-
lates the target power generation voltage based on the sensor
signal. And ECM sends the calculated value as the power genera-
tion command value to IPDM E/R. For the details of the power gen-
eration voltage variable control, refer to
CHG-7, "System
Description".
: Vehicle front
CAUTION:
Do not connect the electrical compon ent or the ground wire directly to the battery terminal. The con-
nection causes the malfunction of th e power generation voltage variable control, and then the battery
discharge may occur.
On Board Diagn osis LogicINFOID:0000000003771616
The MIL will not light up for this self-diagnosis.
NOTE:
If DTC P1553 is displayed with DTC P0643, first pe rform the trouble diagnosis for DTC P0643. Refer to
EC-285
.
DTC Confirmation ProcedureINFOID:0000000003771617
If DTC Confirmation Procedure has been previously conducted, always perform the following before conduct-
ing the next step.
1. Turn ignition swich OFF and wait at least 10 seconds.
2. Turn ignition swich ON.
3. Turn ignition swich OFF and wait at least 10 seconds.
TESTING CONDITION:
Before performing the following procedure, confirm that battery voltage is more than 8V at idle.
1. Start engine and wait at least 10 seconds.
2. Check 1st trip DTC.
3. If 1st trip DTC is detected, go to EC-316, "Diagnosis Procedure"
.
Diagnosis ProcedureINFOID:0000000003771618
1.CHECK GROUND CONNECTIONS
1. Turn ignition switch OFF.
2. Loosen and retighten ground screws on the body.
BBIA0744E
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P1553
1553 Battery current sensor performance The signal voltage transmitted from the
sensor to ECM is higher than the amount
of the maximum power generation.  Harness or connectors
(The sensor circuit is open or shorted.)
 Battery current sensor
Revision: December 20092009 QX56