2009 INFINITI QX56 check engine

DLN-76
< COMPONENT DIAGNOSIS >[ATX14B]
P1829 THROTTLE POSITION SIGNAL (ECM)
P1829 THROTTLE POSITION SIGNAL (ECM)
DescriptionINFOID:0000000003772146
Malfunction is detected in accelerator pedal position si
gnal that is output from ECM through CAN communica-
tion. Also, the signal voltage from accelerator pedal position sensor may be abnormally high or low.
DTC LogicINFOID:0000000003772147
DTC DETECTION LOGIC
DTC CONFIRMATION PROCEDURE
1.DTC CONFIRMATION PROCEDURE
1. Turn ignition switch ON.
2. Perform self-diagnosis.
Is DTC P1829 displayed?
YES >> Perform diagnosis procedure. Refer to DLN-76, "Diagnosis Procedure".
NO >> Inspection End.
Diagnosis ProcedureINFOID:0000000003772148
1.CHECK DTC WITH ECM
Perform self-diagnosis with ECM. Refer to EC-63, "CONSULT-III Function (ENGINE)"
.
Is any malfunction detec ted by self-diagnosis?
YES >> Check the malfunctioning system.
NO >> GO TO 2.
2.CHECK TRANSFER CONTROL UNIT
Check transfer control unit input/output signal. Refer to DLN-81, "Reference Value"
.
Are inspection results normal?
YES >> GO TO 3.
NO >> Check transfer control unit pin terminals fo r damage or loose connection with harness connector.
If any items are damaged, repair or replace damaged parts.
3.CHECK DTC
Perform the self-diagnosis, after driving a vehicle for a while.
Are inspection results normal?
YES >> Inspection End.
NO >> Perform self-diagnosis with ECM again.
DTC CONSULT-III Diagnostic item is detected when... Reference
[P1829] THROTTLE POSI SEN  Malfunction is detected in accelerator
pedal position signal that is output
from ECM through CAN communica-
tion.
 Signal voltage from accelerator pedal position sensor is abnormally high or
low. Refer to
DLN-76
.
Revision: December 20092009 QX56

TRANSFER CONTROL UNITDLN-81
< ECU DIAGNOSIS > [ATX14B]
C
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G H
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B
DLN
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ECU DIAGNOSIS
TRANSFER CONTROL UNIT
Reference ValueINFOID:0000000003772158
VALUE ON THE DIAGNOSIS TOOL
CONSULT-III data monitor item
Monitored item [Unit] Content Condition Display value
VHCL/S SEN·FR [km/h]
or [mph] Wheel speed (Front
wheel) Vehicle stopped 0 km/h (0 mph)
Vehicle running
CAUTION:
Check air pressure of tire under standard condition.
Approximately
equal to the indica-
tion on speedome-
ter (Inside of
±
10%)
VHCL/S SEN·RR [km/h]
or [mph] Wheel speed (Rear
wheel) Vehicle stopped 0 km/h (0 mph)
Vehicle running
CAUTION:
Check air pressure of tire under standard condition.
Approximately
equal to the indica-
tion on speedome-
ter (Inside of
±
10%)
ENGINE SPEED [rpm ] Engine speed Engine stopped
(Engine speed: Less than 400 rpm)
0 rpm
Engine running
(Engine speed: 400 rpm or more) Approximately
equal to the indica-
tion on tachometer
THRTL POS SEN [V] Accelertor pedal position
(APP) sensor signal volt-
age Accelerator pedal: Released Approx. 0.5V
Accelerator pedal: Fully depressed Approx. 4.0V
FLUID TEMP SE [V] Transfer fluid tempera-
ture signal voltage Transfer fluid temperature approx. 20 - 80
°C (68 - 176 °F) Approx. 1.1 - 0.3V
BATTERY VOLT [V] Power supply voltage for
transfer control unit Ignition switch: ON Battery voltage
2WD SWITCH [ON/OFF] Input condition from 4WD
shift switch 4WD shift switch: 2WD ON
4WD shift switch: AUTO, 4H or 4LO OFF
AUTO SWITCH [ON/
OFF] Input condition from 4WD
shift switch 4WD shift switch: AUTO ON
4WD shift switch: 2WD, 4H or 4LO OFF
LOCK SWITCH [ON/
OFF] Input condition from 4WD
shift switch 4WD shift switch: 4H ON
4WD shift switch: 2WD, AUTO or 4LO OFF
4L SWITCH [ON/OFF] Input condition from 4WD
shift switch 4WD shift switch: 4LO ON
4WD shift switch: 2WD, AUTO or 4H OFF
N POSI SW TF [ON/
OFF] Condition of neutral-4LO
switch  Vehicle stopped
 Engine running
 A/T selector lever N posi-
tion
 Brake pedal depressed 4WD shift switch: 2WD,
AUTO or 4H
OFF
4WD shift switch: 4H to
4LO (While actuator mo-
tor is operating.) OFF
→ON
4WD shift switch: 4LO to
4H (While actuator motor
is operating.) ON
→OFF
4WD shift switch: 4LO ON
Revision: December 20092009 QX56

TRANSFER CONTROL UNITDLN-83
< ECU DIAGNOSIS > [ATX14B]
C
EF
G H
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K L
M A
B
DLN
N
O P
VHCL/S COMP [km/h] or
[mph] Vehicle speed Vehicle stopped 0 km/h (0 mph)
Vehicle running
CAUTION:
Check air pressure of tire under standard condition. Approximately
equal to the indica-
tion on speedome-
ter (Inside of
±
10%)
COMP CL TORQ [kgm] Condition of control
torque  Vehicle stopped
 Engine running
 A/T selector lever N posi-
tion
 Brake pedal depressed 4WD shift switch: 2WD 0 kg-m
4WD shift switch: AUTO
39 - 1,353 N·m
(4 - 138 kg-m, 29 - 998 ft-lb)
4WD shift switch: 4H or
4LO 1,353 N·m
(138 kg-m, 998 ft-
lb)
DUTY SOLENOID [%] Condition of clutch pres-
sure solenoid  Vehicle stopped
 Engine running
 A/T selector lever N posi-
tion
 Brake pedal depressed 4WD shift switch: 2WD 4%
4WD shift switch: AUTO 96 - 4%
4WD shift switch: 4H or
4LO
4%
2-4WD SOL [ON/OFF] Condition of 2-4WD shift
solenoid valve  Vehicle stopped
 Engine running
 A/T selector lever N posi-
tion
 Brake pedal depressed 4WD shift switch: 2WD OFF
4WD shift switch: AUTO
ON
4WD shift switch: 4H
4WD shift switch: 4LO
4WD shift switch: AUTO
(Wait function is operat-
ing.) OFF
4WD shift switch: 4H
(Wait function is operat-
ing.) OFF
2-4WD SOL MON [ON/
OFF] Check signal for transfer
control unit signal output  Vehicle stopped
 Engine running
 A/T selector lever N posi-
tion
 Brake pedal depressed 4WD shift switch: 2WD OFF
4WD shift switch: AUTO
ON
4WD shift switch: 4H
4WD shift switch: 4LO
4WD shift switch: AUTO
(Wait function is operat-
ing.) OFF
4WD shift switch: 4H
(Wait function is operat-
ing.) OFF
MOTOR RELAY [ON/
OFF] Condition of transfer mo-
tor relay  Accelerator pedal de-
pressed
 Vehicle stopped
 Engine running
 Brake pedal depressed 4WD shift switch: 2WD OFF
4WD shift switch: AUTO
or 4LO (A/T selector lever
P or N position)
OFF
(ON for approx. 2 sec. after shifting to P and N.)
4WD shift switch: AUTO
or 4LO (Except for A/T se-
lector lever P or N posi-
tion) ON
4WD shift switch: 4H (A/T
selector lever P position) OFF
(ON for approx. 2 sec. after shifting to P.)
4WD shift switch: 4H (Ex-
cept for A/T selector lever
P position) ON
Monitored item [Unit] Content Condition Display value
Revision: December 20092009 QX56

DLN-84
< ECU DIAGNOSIS >[ATX14B]
TRANSFER CONTROL UNIT
MOTOR RELAY MON
[ON/OFF]Check signal for transfer
control unit signal output  Accelerator pedal de-
pressed
 Vehicle stopped
 Engine running
 Brake pedal depressed 4WD shift switch: 2WD OFF
4WD shift switch: AUTO
or 4LO (A/T selector lever
P or N position)
OFF
(ON for approx. 2
sec. after shifting to P and N.)
4WD shift switch: AUTO
or 4LO (Except for A/T se-
lector lever P or N posi-
tion) ON
4WD shift switch: 4H (A/T
selector lever P position) OFF
(ON for approx. 2
sec. after shifting to P.)
4WD shift switch: 4H (Ex-
cept for A/T selector lever
P position) ON
4WD FAIL LAMP [ON/
OFF] Condition of 4WD warn-
ing lamp 4WD warning lamp: ON ON
4WD warning lamp: OFF OFF
2WD IND [ON/OFF] Condition of 4WD shift in-
dicator lamp (2WD indi-
cator lamp) 2WD indicator lamp of 4WD shift indicator lamp: OFF OFF
2WD indicator lamp of 4WD shift indicator lamp: ON ON
AUTO IND [ON/OFF] Condition of 4WD shift in-
dicator lamp
(AUTO indi-
cator lamp) AUTO indicator lamp of 4WD shift indicator lamp: OFF OFF
AUTO indicator lamp of 4WD shift indicator lamp: ON ON
LOCK IND [ON/OFF] Condition of 4WD shift in-
dicator lamp (Lock indi-
cator lamp) Lock indicator lamp of 4WD shift indicator lamp: OFF OFF
Lock indicator lamp of 4WD shift indicator lamp: ON ON
4L IND [ON/OFF] Condition of 4LO indica-
tor lamp condition 4LO indicator lamp: OFF OFF
4LO indicator lamp: ON ON
ATP IND [ON/OFF] Condition of ATP indica-
tor lamp ATP indicator lamp: ON ON
AT P i n d i c a t o r l a m p : O F F O F F
SHIFT POS SW1 [ON/
OFF] Condition of actuator po-
sition switch 1
(Low)  Vehicle stopped
 Engine running
 A/T selector lever N posi-
tion
 Brake pedal depressed 4WD shift switch: 4LO ON
4WD shift switch: 2WD,
AUTO or 4H
OFF
SHIFT POS SW2 [ON/
OFF] Condition of actuator po-
sition switch 2
(High)  Vehicle stopped
 Engine running
 A/T selector lever N posi-
tion
 Brake pedal depressed 4WD shift switch: 4H,
AUTO or 2WD
ON
4WD shift switch: 4LO OFF
SHIFT ACT1 [ON/OFF] Output condition to actu-
ator motor (High)  Vehicle stopped
 Engine running
 A/T selector lever N posi-
tion
 Brake pedal depressed
4WD shift switch: 4H to
4LO (Wait function is op-
erating.) ON
Except the above OFF
SHIFT AC MON1 [ON/
OFF] Check signal for transfer
control unit signal output  Vehicle stopped
 Engine running
 A/T selector lever N posi-
tion
 Brake pedal depressed 4WD shift switch: 4H to
4LO (Wait function is op-
erating.)
ON
Except the above OFF
SHIFT ACT2 [ON/OFF] Output condition to actu-
ator motor (Low)  Vehicle stopped
 Engine running
 A/T selector lever N posi-
tion
 Brake pedal depressed 4WD shift switch: 4LO to
4H (Wait function is oper-
ating.)
ON
Except the above OFF
Monitored item [Unit] Content Condition Display value
Revision: December 20092009 QX56

TRANSFER CONTROL UNITDLN-85
< ECU DIAGNOSIS > [ATX14B]
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B
DLN
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PHYSICAL VALUES
Terminal Layout
SHIFT AC MON2 [ON/
OFF] Check signal for transfer
control unit signal output  Vehicle stopped
 Engine running
 A/T selector lever N posi-
tion
 Brake pedal depressed 4WD shift switch: 4LO to
4H (Wait function is oper-
ating.)
ON
Except the above OFF
T/F F SPEED [km/h] or
[mph] Displayed, but do not use.
A/T R SPEED [km/h] or
[mph] Condition of vehicle
speed sensor A/T (output
speed sensor)
During driving Approximately
matches the out-
put shaft speed.
AT GEAR POSI [1/2/3/4/
5] Condition of A/T selector
lever position
Displays actual A/T gear position. 1
2
3
4
5
Monitored item [Unit] Content Condition Display value
WDIA0378E
Te r m i n a l
Wire
color Item Condition Data (Approx.)
1 GR 2-4WD shift solenoid valve  Vehicle stopped
 Engine running
 A/T selector lever
“N” position
 Brake pedal de- pressed 4WD shift switch: 2WD 0V
4WD shift switch: AUTO, 4H or 4LO Battery voltage
2 B/W 4WD shift indicator lamp
(2WD indicator lamp) 2WD indicator lamp: OFF Battery voltage
2WD indicator lamp: ON 0V
3 B Ground Always 0V
4 Y/L Transfer shift high relay  Vehicle stopped
 Engine running
 A/T selector lever
“N” position
 Brake pedal de-
pressed 4WD shift switch: 4H to 4LO (“Wait” func-
tion is operating.)
Battery voltage
Except the above 0V
5 W/B 4WD warning lamp 4WD warning lamp: ON 0V
4WD warning lamp: OFF Battery voltage
6 B Ground Always 0V
7 L CAN-H — —
8 P CAN-L — —
9G/W 4WD shift switch
(2WD) Ignition switch: ON4WD shift switch: 2WD Battery voltage
4WD shift switch: AUTO, 4H or 4LO 0V
Revision: December 20092009 QX56

DLN-102
< SYMPTOM DIAGNOSIS >[ATX14B]
4WD SYSTEM SYMPTOMS
SYMPTOM DIAGNOSIS
4WD SYSTEM SYMPTOMS
Symptom TableINFOID:0000000003772161
If 4WD warning lamp turns ON, perform self-diagnosis. Refer to
DLN-18, "CONSULT-III Function (ALL MODE AWD/4WD)".
NOTE:
 Light tight-corner braking symptom may occur depending on driving conditions in AUTO mode. This is not a
malfunction.
 Heavy tight-corner braking symptom occurs when vehicle is driven in the following conditions: 4WD shift
switch is 4H or 4LO, steering wheel is turned fully to either side.
Symptom Condition Reference page
4WD shift indicator lamp and 4LO indicator lamp do not turn ON
(4WD shift indicator lamp and 4LO indicator lamp check) Ignition switch: ON
DLN-103
4WD warning lamp does not turn ON
(4WD warning lamp check) Ignition switch: ON
DLN-105
4WD shift indicator lamp or 4LO indicator lamp does not change Engine running DLN-107
ATP warning lamp does not turn ON Engine runningDLN-109
4WD shift indicator lamp keeps flashing Engine running DLN-111
4WD warning lamp flashes rapidly (2 times/second) While drivingDLN-112
4WD warning lamp flashes slowly
(1 time/2 seconds)While driving
DLN-113
Heavy tight-corner braking symptom occurs
(See NOTE.)  While driving
AUTO mode
 Steering wheel is turned fully
to either side DLN-114
ATP switch does not operate Engine running
DLN-116
4WD system does not operate While drivingDLN-118
Revision: December 20092009 QX56

4WD WARNING LAMP DOES NOT TURN ONDLN-105
< SYMPTOM DIAGNOSIS > [ATX14B]
C
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G H
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M A
B
DLN
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4WD WARNING LAMP DOES NOT TURN ON
DescriptionINFOID:0000000003772164
4WD warning lamp does not turn ON when turning ignition switch to ON.
Diagnosis ProcedureINFOID:0000000003772165
1.CHECK TRANSFER CONTROL UNIT PO WER SUPPLY AND GROUND CIRCUITS
Refer to DLN-22, "Diagnosis Procedure"
.
Are the inspection results normal?
YES >> GO TO 2.
NO >> Repair as necessary.
2.CHECK COMBINATION METER POWER SUPPLY AND GROUND CIRCUITS
Refer to MWI-30, "COMBINATION METER : Diagnosis Procedure"
.
Are the inspection results normal?
YES >> GO TO 3.
NO >> Perform repairs as necessary.
3.CHECK HARNESS BETWEEN TR ANSFER CONTROL UNIT AND COMBINATION METER
1. Turn ignition switch OFF. (Stay for at least 5 seconds.)
2. Disconnect transfer control unit and combination meter harness connectors.
3. Check continuity between the following terminals.
- Transfer control unit harness connector E142 (A) terminal 5 and combination meter harness connector M23 (B) terminal 49.
Also check harness for short to ground and short to power.
Are the inspection results normal?
YES >> GO TO 4.
NO >> Repair or replace damaged parts.
4.CHECK INDICATOR LAMP CIRCUIT
1. Connect combination meter harness connector.
2. Turn ignition switch ON. (Do not start engine.)
3. Ground the following terminal using suitable wiring.
- Transfer control unit harness connector E142 terminal 5 and ground.
Does 4WD warning lamp turn on?
YES >> GO TO 5.
NO >> Replace combination meter. Refer to MWI-102,
"Removal and Installation".
5.SYMPTOM CHECK
Check again.
Are the inspection results normal?
YES >> Inspection End.
NO >> GO TO 6.
6.CHECK TRANSFER CONTROL UNIT
Check transfer control unit input/output signal. Refer to DLN-81, "Reference Value"
.
Continuity should exist.
AWDIA0187ZZ
SDIA2774E
Revision: December 20092009 QX56

DLN-110
< SYMPTOM DIAGNOSIS >[ATX14B]
ATP WARNING LAMP DOES NOT TURN ON
- Transfer control unit harness
connector E143 (B) terminal 40
and combination meter harness connector M23 (A) terminal 44.
Also check harness for short to ground and short to power.
Are the inspection results normal?
YES >> GO TO 6.
NO >> Repair or replace damaged parts.
6.CHECK ATP WARNING LAMP CIRCUIT
1. Place A/T selector lever in P position.
2. Connect combination meter harness connector and transfer control unit harness connector.
3. Disconnect ATP switch harness connector.
4. Ground the following terminal using suitable wiring.
- ATP switch harness connector F55 terminal 8 and ground.
5. Turn ignition switch ON. (Do not start engine.)
Does indicator lamp turn on?
YES >> GO TO 7.
NO >> Replace combination meter. Refer to MWI-102,
"Removal and Installation".
7.SYMPTOM CHECK
Check again.
Are the inspection results normal?
YES >> Inspection End.
NO >> GO TO 8.
8.CHECK TRANSFER CONTROL UNIT
Check transfer control unit input/output signal. Refer to DLN-81, "Reference Value"
.
Are the inspection results normal?
YES >> GO TO 9.
NO >> Check transfer control unit pin terminals fo r damage or loose connection with harness connector.
If any items are damaged, repair or replace damaged parts.
9.CHECK TRANSFER INNER PARTS
1. Disassemble transfer assembly. Refer to DLN-142, "Disassembly and Assembly"
.
2. Check transfer inner parts.
Are the inspection results normal?
YES >> Inspection End.
NO >> Repair or replace damaged parts. 40 to 44: Continuity should not exist.
44 to 40: Continuity should exist.
AWDIA0186ZZ
SDIA2769E
Revision: December 20092009 QX56