2010 INFINITI QX56 ESP

EC-308
< COMPONENT DIAGNOSIS >[VK56DE]
P1226 TP SENSOR
P1226 TP SENSOR
Component DescriptionINFOID:0000000005149358
Electric throttle control actuator consists of throttle control motor,
throttle position sensor, etc. The throttle position sensor responds to
the throttle valve movement.
The throttle position sensor has the two sensors. These sensors are
a kind of potentiometers which transform the throttle valve position
into output voltage, and emit the voltage signal to the ECM. In addi-
tion, these sensors detect the opening and closing speed of the
throttle valve and feed the voltage signals to the ECM. The ECM
judges the current opening angle of the
throttle valve from these sig-
nals and the ECM controls the throttle control motor to make the
throttle valve opening angle properly in response to driving condi-
tion.
On Board Diagn osis LogicINFOID:0000000005149359
The MIL will not light up for this self-diagnosis.
DTC Confirmation ProcedureINFOID:0000000005149360
NOTE:
If DTC Confirmation Procedure has been previously conducted, always perform the following procedure
before conducting the next step.
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 10 V at idle.
1. Turn ignition switch ON.
2. Turn ignition switch OFF and wait at least 10 seconds.
3. Turn ignition switch ON.
4. Repeat steps 2 and 3 for 32 times.
5. Check 1st trip DTC.
6. If 1st trip DTC is detected, go to EC-308, "
Diagnosis Procedure".
Diagnosis ProcedureINFOID:0000000005149361
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.
OK or NG
OK >> GO TO 2.
NG >> Remove the foreign matter and clean the electric throttle control actuator inside.
PBIB0145E
DTC No. Trouble diagnosis name DTC detecting conditionPossible cause
P1226
1226 Closed throttle position learning
performance Closed throttle position learning is not performed
successfully, repeatedly. • Electric throttle control actuator
(TP sensor 1 and 2)
BBIA0364E
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P2101 ELECTRIC THROTTLE CONTROL FUNCTIONEC-359
< COMPONENT DIAGNOSIS > [VK56DE]
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P2101 ELECTRIC THROTTLE CONTROL FUNCTION
DescriptionINFOID:0000000005149426
NOTE:
If DTC P2101 is displayed with DTC P2100 or 2119,
first perform the trouble diagnosis for DTC P2100
or P2119. Refer to EC-356
or EC-365.
Electric throttle control actuator consists of throttle control mo tor, throttle position sensor, etc.
The throttle control motor is operated by the ECM and it opens and closes the throttle valve.
The current opening angle of the throttle valve is detected by the throttle position sensor and it provides feed-
back to the ECM to control the throttle control motor to make the throttle valve opening angle properly in
response to driving condition.
On Board Diagnosis LogicINFOID:0000000005149427
This self-diagnosis has the on e trip detection logic.
FA I L - S A F E M O D E
When the malfunction is detected, ECM ent ers fail-safe mode and the MIL lights up.
DTC Confirmation ProcedureINFOID:0000000005149428
NOTE:
If DTC Confirmation Procedure has been previously conducted, always perform the following procedure
before conducting the next step.
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 when
engine is running.
1. Turn ignition switch ON and wait at least 2 seconds.
2. Start engine and let it idle for 5 seconds.
3. Check DTC.
4. If DTC is detected, go to EC-359, "
Diagnosis Procedure".
Diagnosis ProcedureINFOID:0000000005149429
1.CHECK GROUND CONNECTIONS
1. Turn ignition switch OFF.
2. Loosen and retighten three ground screws on the body.
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P2101
2101 Electric throttle control
performance Electric throttle control function does not oper-
ate properly. • Harness or connectors
(Throttle control motor circuit is open or
shorted)
• Electric throttle control actuator
Engine operating condition in fail-safe mode
ECM stops the electric throttle control actuator control, throttle valve is maintained at a fixed opening (approx. 5 degrees) b y the return
spring.
Revision: April 20092010 QX56

P2118 THROTTLE CONTROL MOTOREC-363
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P2118 THROTTLE CONTROL MOTOR
Component DescriptionINFOID:0000000005149431
The throttle control motor is operated by the
ECM and it opens and closes the throttle valve.
The current opening angle of the throttle valve is detected by the throttle position sensor and it provides feed-
back to the ECM to control the throttle control motor to make the throttle valve opening angle properly in
response to driving condition.
On Board Diagnosis LogicINFOID:0000000005149432
This self-diagnosis has the on e trip detection logic.
FA I L - S A F E M O D E
When the malfunction is detected, the ECM enters fail-safe mode and the MIL lights up.
DTC Confirmation ProcedureINFOID:0000000005149433
1. If DTC Confirmation Procedure has been previously conducted, always perform the following procedure
before conducting the next step.
a. Turn ignition switch OFF and wait at least 10 seconds.
b. Turn ignition switch ON.
c. Turn ignition switch OFF and wait at least 10 seconds.
2. Turn ignition switch ON and wait at least 2 seconds.
3. Start engine and let it idle for 5 seconds.
4. Check DTC.
5. If DTC is detected, go to EC-363, "
Diagnosis Procedure".
Diagnosis ProcedureINFOID:0000000005149434
1.CHECK GROUND CONNECTIONS
1. Turn ignition switch OFF.
2. Loosen and retighten three ground screws on the body. Refer to EC-85, "
Ground Inspection".
OK or NG
OK >> GO TO 2.
NG >> Repair or replace ground connections.
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P2118
2118 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)
Engine operating condition in fail-safe mode
ECM stops the electric throttle control actuator control, throttle valve is maintained at a fixed opening (approx. 5 degrees) b y the return
spring.
BBIA0354E
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P2119 ELECTRIC THROTTLE CONTROL ACTUATOREC-365
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P2119 ELECTRIC THROTTLE CONTROL ACTUATOR
Component DescriptionINFOID:0000000005149436
Electric throttle control actuator consists of throttle control mo
tor, throttle position sensor, etc.
The throttle control motor is operated by the ECM and it opens and closes the throttle valve.
The throttle position sensor detects the throttle valve position, and the opening and closing speed of the throt-
tle valve and feeds the voltage signals to the ECM. T he ECM judges the current opening angle of the throttle
valve from these signals and the ECM controls the thrott le control motor to make the throttle valve opening
angle properly in response to driving condition.
On Board Diagnosis LogicINFOID:0000000005149437
This self-diagnosis has one trip detection logic.
FA I L - S A F E M O D E
When the malfunction is detected, ECM ent ers fail-safe mode and the MIL lights up.
DTC Confirmation ProcedureINFOID:0000000005149438
NOTE:
•Perform PROCEDURE FOR MALFUNCTION A AND B first. If the DTC cannot be confirmed, perform
PROCEDURE FOR MALFUNCTION C.
• If DTC Confirmation Procedure has been previously conducted, always perform the following procedure before conducting the next step
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.
PROCEDURE FOR MALFUNCTION A AND B
1. Turn ignition switch ON and wait at least 1 second.
2. Shift selector lever to D position and wait at least 3 seconds.
3. Shift selector lever to P or N position.
4. Turn ignition switch OFF and wait at least 10 seconds.
5. Turn ignition switch ON and wait at least 1 second.
6. Shift selector lever to D position and wait at least 3 seconds.
7. Shift selector lever to P or N position.
8. Turn ignition switch OFF, wait at least 10 seconds and then turn ON.
9. Check DTC.
10. If DTC is detected, go to EC-366, "
Diagnosis Procedure".
PROCEDURE FOR MALFUNCTION C
DTC No. Trouble diagnosis name DTC detecting conditionPossible cause
P2119
2119 Electric throttle control
actuator A)
Electric throttle control actuator does not func-
tion properly due to the return spring malfunc-
tion.
• Electric throttle control actuator
B) Throttle valve opening angle in fail-safe mode is
not in specified range.
C) ECM detect the throttle valve is stuck open.
Detected items Engine operating condition in fail-safe mode
Malfunction A The ECM controls the electric throttle actuator by regulating the throttle opening around the idle position.
The engine speed will not rise more than 2,000 rpm.
Malfunction B ECM controls the electric throttle control actuator by regulating the throttle opening to 20 degrees or less.
Malfunction C While the vehicle is driving, it slows down gradually by fuel cut. After the vehicle stops, the engine stalls.
The engine can restart in N or P position, and engine speed will not exceed 1,000 rpm or more.
Revision: April 20092010 QX56

EC-374
< COMPONENT DIAGNOSIS >[VK56DE]
P2135 TP SENSOR
P2135 TP SENSOR
Component DescriptionINFOID:0000000005149450
Electric throttle control actuator consists of throttle control motor,
throttle position sensor, etc. The throttle position sensor responds to
the throttle valve movement.
The throttle position sensor has the two sensors. These sensors are
a kind of potentiometers which transform the throttle valve position
into output voltage, and emit the voltage signal to the ECM. In addi-
tion, these sensors detect the opening and closing speed of the
throttle valve and feed the voltage signals to the ECM. The ECM
judges the current opening angle of the
throttle valve from these sig-
nals and the ECM controls the throttle control motor to make the
throttle valve opening angle properly in response to driving condi-
tion.
On Board Diagn osis LogicINFOID:0000000005149451
This self-diagnosis has the one trip detection logic.
FA I L - S A F E M O D E
When the malfunction is detected, the ECM enters fail-safe mode and the MIL lights up.
DTC Confirmation ProcedureINFOID:0000000005149452
NOTE:
If DTC Confirmation Procedure has been previously conducted, always perform the following procedure
before conducting the next step.
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 8 V at idle.
1. Start engine and let it idle for 1 second.
2. Check DTC.
3. If DTC is detected, go to EC-374, "
Diagnosis Procedure".
Diagnosis ProcedureINFOID:0000000005149453
1.CHECK GROUND CONNECTIONS
1. Turn ignition switch OFF.
2. Loosen and retighten three ground screws on the body.
PBIB0145E
DTC No. Trouble diagnosis name DTC detecting conditionPossible cause
P2135
2135 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 and 2 circuit is open or
shorted.)
(APP sensor 2 circuit is shorted.)
• Electric throttle control actuator (TP sensor 1 and 2)
• Accelerator pedal position sensor
(APP sensor 2)
Engine operation condition in fail-safe mode
The ECM controls the electric throttle control actuator in regulating the throttle opening in order for the idle position to be within +10
degrees.
The ECM regulates the opening speed of the throttle valve to be slower than the normal condition.
So, the acceleration will be poor.
Revision: April 20092010 QX56

EC-464
< ECU DIAGNOSIS >[VK56DE]
ECM
Data which are stored in the ECM memory, along with the
1st trip DTC, are called 1st trip freeze frame data.
The data, stored together with the DTC data, are ca lled freeze frame data and displayed on CONSULT-III or
GST. The 1st trip freeze frame data can only be disp layed on the CONSULT-III screen, not on the GST. For
details, see EC-63, "
CONSULT-III Function (ENGINE)".
Only one set of freeze frame data (either 1st trip freez e frame data or freeze frame data) can be stored in the
ECM. 1st trip freeze frame data is stored in the ECM memory along with the 1st trip DTC. There is no priority
for 1st trip freeze frame data and it is updated each time a different 1st trip DTC is detected. However, once
freeze frame data (2nd trip detection/MIL on) is stored in the ECM memory, 1st trip freeze frame data is no
longer stored. Remember, only one set of freeze frame data can be stored in the ECM. The ECM has the fol-
lowing priorities to update the data.
For example, the EGR malfunction (Priority: 2) was detected and the fr eeze frame data was stored in the 2nd
trip. After that when the misfire (Priority: 1) is detected in another trip, the freeze frame data will be updated
from the EGR malfunction to the misfire. The 1st trip freeze frame data is updated each time a different mal-
function is detected. There is no priority for 1st trip freeze frame data. However, once freeze frame data is
stored in the ECM memory, 1st trip freeze data is no longer stored (because only one freeze frame data or 1st
trip freeze frame data can be stored in the ECM). If fr eeze frame data is stored in the ECM memory and freeze
frame data with the same priority occurs later, t he first (original) freeze frame data remains unchanged in the
ECM memory.
Both 1st trip freeze frame data and freeze frame dat a (along with the DTCs) are cleared when the ECM mem-
ory is erased. Procedures for clearing the ECM me mory are described in "HOW TO ERASE EMISSION-
RELATED DIAGNOSTIC INFORMATION".
SYSTEM READINESS TEST (SRT) CODE
System Readiness Test (SRT) code is specified in Service $01 of SAE J1979.
As part of an enhanced emissions test for Inspection & Ma intenance (I/M), certain states require the status of
SRT be used to indicate whether the ECM has completed self-diagnosis of major emission s\
ystems and com-
ponents. Completion must be verified in order for the emissions inspection to proceed.
If a vehicle is rejected for a State emissions inspec tion due to one or more SRT items indicating “INCMP”, use
the information in this Service Manual to set the SRT to “CMPLT”.
In most cases the ECM will automatically complete its self-diagnosis cycle during normal usage, and the SRT
status will indicate “CMPLT” for each application system. Once set as “CMPLT”, the SRT status remains
“CMPLT” until the self-diagnosis memory is erased.
Occasionally, certain portions of the self-diagnostic test may not be completed as a result of the customer's
normal driving pattern; the SRT will indicate “INCMP” for these items.
NOTE:
The SRT will also indicate “INCMP” if the self-diagnosis memory is erased for any reason or if the ECM mem-
ory power supply is interrupted for several hours.
If, during the state emissions inspection, the SRT indicates “CMPLT” for all test items, the inspector will con-
tinue with the emissions test. However, if the SRT indi cates “INCMP” for one or more of the SRT items the
vehicle is returned to the customer untested.
NOTE:
If MIL is ON during the state emissions inspection, the vehicle is also returned to the customer untested even
though the SRT indicates “CMPLT” for all test items. Therefore, it is important to check SRT (“CMPLT”) and
DTC (No DTCs) before the inspection.
SRT Item
The table below shows required self-diagnostic items to set the SRT to “CMPLT”.
Priority Items
1 Freeze frame data Misfire — DTC: P0300 - P0308
Fuel Injection System Function — DTC: P0171, P0172, P0174, P0175
2 Except the above items (Includes A/T related items)
3 1st trip freeze frame data
SRT item
(CONSULT-III indication) Performance
Priority* Required self-diagnostic items to set the SRT to “CMPLT”
Corresponding
DTC No.
CATALYST 2 Three way catalyst function P0420, P0430
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ECM
EC-465
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*: If completion of several SRTs is required, perform driving patterns (DTC confirmation procedure), one by one based on the pr
iority for
models with CONSULT-III.
SRT Set Timing
SRT is set as “CMPLT” after self-diagnosis has been performed one or more times. Completion of SRT is
done regardless of whether the result is OK or NG. T he set timing is different between OK and NG results and
is shown in the table below.
OK: Self-diagnosis is carried out and the result is OK.
NG: Self-diagnosis is carried out and the result is NG.
—: Self-diagnosis is not carried out.
When all SRT related self-diagnoses showed OK results in a single cycle (Ignition OFF-ON-OFF), the SRT will
indicate “CMPLT”. → Case 1 above
When all SRT related self-diagnoses showed OK results through several different cycles, the SRT will indicate
“CMPLT” at the time the respective se lf-diagnoses have at least one OK result. → Case 2 above
If one or more SRT related self-diagnoses showed NG results in 2 consecutive cycles, the SRT will also indi-
cate “CMPLT”. → Case 3 above
The table above shows that the minimum number of cyc les for setting SRT as “INCMP” is one (1) for each
self-diagnosis (Case 1 & 2) or two (2) for one of self-di agnoses (Case 3). However, in preparation for the state
emissions inspection, it is unnecessary for each self-di agnosis to be executed twice (Case 3) for the following
reasons:
• The SRT will indicate “CMPLT” at the time the respective self-diagnoses have one (1) OK result.
• The emissions inspection requires “CMPLT” of the SRT only with OK self-diagnosis results.
• When, during SRT driving pattern, 1st trip DTC (NG) is detected prior to “CMPLT” of SRT, the self-diagnosis
memory must be erased from ECM after repair.
EVAP SYSTEM 2 EVAP control system purge flow monitoring P0441
1 EVAP control system P0442
2 EVAP control system P0456
HO2S 2 Air fuel ratio (A/F) sensor 1 P0133, P0153
Heated oxygen sensor 2 P0137, P0157
Heated oxygen sensor 2 P0138, P0158
Heated oxygen sensor 2 P0139, P0159
SRT item
(CONSULT-III indication) Performance
Priority* Required self-diagnostic items to set the SRT to “CMPLT” Corresponding
DTC No.
Self-diagnosis result Example
Diagnosis Ignition cycle
← ON → OFF ← ON → OFF ← ON → OFF ← ON →
All OK Case 1 P0400OK (1) — (1)OK (2) — (2)
P0402 OK (1) — (1)— (1)OK (2)
P1402 OK (1) OK (2) — (2)— (2)
SRT of EGR “CMPLT” “CMPLT” “CMPLT” “CMPLT”
Case 2 P0400OK (1) — (1)— (1) — (1)
P0402 — (0)— (0)OK (1) — (1)
P1402 OK (1) OK (2) — (2)— (2)
SRT of EGR “INCMP” “INCMP” “CMPLT” “CMPLT”
NG exists Case 3 P0400OKOK ——
P0402 ——— —
P1402 NG—NG NG
(Consecutive NG)
(1st trip) DTC 1st trip DTC
—1st trip DTC DTC
(= MIL ON)
SRT of EGR “INCMP” “INCMP” “INCMP” “CMPLT”
Revision: April 20092010 QX56

ECM
EC-467
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NO TOOLS
A SRT code itself can not be displayed while only SRT status can be.
1. Turn ignition switch ON and wait 20 seconds.
2. SRT status is indicated as shown below. • When all SRT codes are set, MIL lights up continuously.
• When any SRT codes are not set, MIL will flash periodically for 10 seconds.
How to Set SRT Code
To set all SRT codes, self-diagnosis for the items indicated above must be performed one or more times. Each
diagnosis may require a long period of actual driving under various conditions.
WITH CONSULT-III
Perform corresponding DTC Confirmation Procedure one by one based on Performance Priority in the table
on "SRT Item".
WITHOUT CONSULT-III
The most efficient driving pattern in which SRT codes can be properly set is explained on the next page. The
driving pattern should be performed one or more times to set all SRT codes.
PBIB2317E
Revision: April 20092010 QX56