2011 INFINITI QX56 ignition

B2517 VEHICLE SPEED SIGNALEXL-75
< DTC/CIRCUIT DIAGNOSIS > [XENON TYPE]
C
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G H
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M A
B
EXL
N
O P
B2517 VEHICLE SPEED SIGNAL
DTC LogicINFOID:0000000006213938
DTC DETECTION LOGIC
DTC CONFIRMATION PROCEDURE
1.DTC ERASE
Erase the DTC memory of AFS with CONSULT-III.
>> GO TO 2.
2.DTC CONFIRMATION
1. Turn ignition ON.
2. Select the self-diagnos is with CONSULT-III.
3. Check the self-diagnosis result. Refer to EXL-39, "
DTC Index".
Is DTC
“B2517” detected?
YES >> Refer to EXL-75, "Diagnosis Procedure".
NO >> Refer to GI-40, "
Intermittent Incident".
Diagnosis ProcedureINFOID:0000000006213939
1.COMBINATION METER SELF-DIAGNOSIS
Check the self-diagnosis result wit h CONSULT-III. Check that the co mbination meter does not detect any
DTCs.
Is any DTC detected?
YES >> Check the combination meter Refer to MWI-43, "DTC Index".
NO >> GO TO 2.
2.DTC ERASE
Erase the DTC memory of AFS with CONSULT-III.
Is the memory erased?
YES >> INSPECTION END.
NO >> Replace AFS control unit. Refer to EXL-135, "
Removal and Installation"
DTC No. Trouble diagnosis name DTC detection condition Possible causes
B2517 Vehicle speed signal The vehicle speed signal is not re-
ceived. Combination meter
 AFS control unit
Revision: 2010 May2011 QX56

B2521 ECU CIRCUITEXL-77
< DTC/CIRCUIT DIAGNOSIS > [XENON TYPE]
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EXL
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B2521 ECU CIRCUIT
DTC LogicINFOID:0000000006213942
DTC DETECTION LOGIC
DTC CONFIRMATION PROCEDURE
1.DTC ERASE
Erase the DTC memory of AFS with CONSULT-III.
>> GO TO 2.
2.DTC CONFIRMATION PROCEDURE
1. Turn ignition ON.
2. Select the self-diagnos is with CONSULT-III.
3. Check the self-diagnosis result. Refer to EXL-39, "
DTC Index".
Is DTC
“B2521” detected?
YES >> Refer to EXL-77, "Diagnosis Procedure".
NO >> Refer to GI-40, "
Intermittent Incident".
Diagnosis ProcedureINFOID:0000000006213943
1.CHECK EACH SENSOR POWER SUPPLY
1. Turn ignition switch ON.
2. Check voltage between AFS cont rol unit harness connector and ground.
Is the measurement value within the standard value?
YES >> GO TO 2.
Less than the standard value >>GO TO 3.
Higher than the standard value>>GO TO 4.
2.CHECK EACH SENSOR SIGNAL
Check voltage between AFS control unit harness connector and ground.
DTC No. Trouble diagnosis name Error detection condition Possible cause
B2512 ECU circuit  AFS control unit indicates an applicable
DTC when detecting any of the following
conditions continuously for 2 seconds or
more.
- The swivel position sensor is shorted to
the power supply or the ground.
- The swivel position sensor signal is shorted to the ground.
- The height sensor power supply is short- ed to the power supply or the ground.
- The height sensor signal is shorted to
the ground.
 AFS control unit RAM/ROM error Swivel position sensor
 Swivel position sensor
 Harness and connector
 AFS control unit
Height sensor
 Height sensor
 Harness and connector
 AFS control unit
AFS control unit (RAM/
ROM)
 AFS control unit
(+)
(− ) Vol tag e
(Approx.)
AFS control unit
Connector Terminal
M135 4
Ground 5 V
5
6
24
Revision: 2010 May2011 QX56

EXL-78
< DTC/CIRCUIT DIAGNOSIS >[XENON TYPE]
B2521 ECU CIRCUIT
Is the measurement value within the standard value?
YES >> Replace AFS control unit. Refer to
EXL-135, "Removal and Installation"
Less than the standard value >>GO TO 5.
Higher than the standard value>>GO TO 6.
3.CHECK EACH SENSOR POWER SUPPLY SHORT CIRCUIT
1. Turn ignition switch OFF.
2. Disconnect AFS control unit connector.
3. Check continuity between AFS control unit harness connector and ground.
Is the inspection result normal?
YES >> Replace AFS control unit. Refer to EXL-135, "Removal and Installation"
NO >> Repair or replace harness.
4.CHECK EACH SENSOR POWER SUPPLY SHORT CIRCUIT
1. Turn ignition switch OFF.
2. Disconnect AFS control unit connector.
3. Check voltage between AFS control unit harness connector and ground.
Is the inspection result normal?
YES >> Replace AFS control unit. Refer to EXL-135, "Removal and Installation"
NO >> Repair or replace harness.
5.CHECK EACH SENSOR SIGNAL SHORT CIRCUIT
1. Turn ignition switch OFF.
2. Disconnect AFS control unit connector.
3. Check continuity between AFS control unit harness connector and ground.
(+)
(− ) Vo l ta g e
(Approx.)
AFS control unit
Connector Terminal
M135 9
Ground 0.25 - 4.75 V
23
28
29
AFS control unit
GroundContinuity
Connector Terminal
M135 4
Not existed
5
6
24
(+) (− ) Vo l ta g e
(Approx.)
AFS control unit
Connector Terminal
M135 4
Ground 0 V
5
6
24
Revision: 2010 May2011 QX56

B2521 ECU CIRCUITEXL-79
< DTC/CIRCUIT DIAGNOSIS > [XENON TYPE]
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G H
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EXL
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Is the inspection result normal?
YES >> Replace AFS control unit. Refer to EXL-135, "Removal and Installation"
NO >> Repair or replace harness.
6.CHECK EACH SENSOR SIGNAL SHORT CIRCUIT
1. Turn ignition switch OFF.
2. Disconnect AFS control unit connector.
3. Turn ignition switch ON.
4. Check voltage between AFS cont rol unit harness connector and ground.
Is the inspection result normal?
YES >> Replace AFS control unit. Refer to EXL-135, "Removal and Installation"
NO >> Repair or replace harness.
AFS control unit
GroundContinuity
Connector Terminal
M135 9
Not existed
23
28
29
(+)
(− ) Vol tag e
(Approx.)
AFS control unit
Connector Terminal
M135 9
Ground 0 V
23
28
29
Revision: 2010 May2011 QX56

EXL-82
< DTC/CIRCUIT DIAGNOSIS >[XENON TYPE]
U1000 CAN COMM CIRCUIT
U1000 CAN COMM CIRCUIT
DescriptionINFOID:0000000006213948
CAN (Controller Area Network) is the serial transmissi
on for real time application. CAN is the multiplex com-
munication for the vehicle with superior data transmi ssion speed and error detection ability. Many electronic
control units are equipped on the vehicle. These control units do not operate individually, but associates with
other control units by sharing information. In CA N communication, each control unit is connected with two
communication lines (CAN-H and CAN-L). Much inform ation is transmitted with fewer communication lines
than before. Each control unit transmits/rec eives data and reads the necessary data only.
CAN Communication Signal Chart. Refer to LAN-27, "
CAN COMMUNICATION SYSTEM : CAN System Spec-
ification Chart".
DTC LogicINFOID:0000000006213949
DTC DETECTION LOGIC
Diagnosis ProcedureINFOID:0000000006213950
1.PERFORM SELF DIAGNOSTIC
1. Turn ignition switch ON and wait for 2 seconds or more.
2. Check “Self Diagnostic Result”.
Is
“CAN COMM CIRCUIT” displayed?
YES >> Refer to LAN-18, "Trouble Diagnosis Flow Chart".
NO >> Refer to GI-40, "
Intermittent Incident".
DTC No. Trouble diagnosis name DTC detection condition Possible causes
U1000 CAN communication circuit When AFS control unit does not trans-
mit/receive CAN communication signal
continuously for 2 seconds or more
CAN communication system
Revision: 2010 May2011 QX56

EXL-84
< DTC/CIRCUIT DIAGNOSIS >[XENON TYPE]
POWER SUPPLY AND GROUND CIRCUIT
POWER SUPPLY AND GROUND CIRCUIT
AFS CONTROL UNIT
AFS CONTROL UNIT : Diagnosis ProcedureINFOID:0000000006213953
1.FUSE INSPECTION
Check that the following fuses are not fusing.
Is the inspection result normal?
YES >> GO TO 2.
NO >> Repair the applicable circuit. And then replace the fuse.
2.CHECK POWER SUPPLY CIRCUIT
1. Turn ignition switch OFF.
2. Disconnect AFS control unit harness connector.
3. Turn ignition switch ON.
4. Check voltage between AFS control unit harness connector and ground.
Is the inspection result normal?
YES >> GO TO 3.
NO >> Repair harness or connector.
3.CHECK GROUND CIRCUIT
1. Turn ignition switch OFF.
2. Check continuity between AFS control unit harness connectors and ground.
Is the inspection result normal?
YES >> Power supply and ground circuit are normal.
NO >> Repair harness or connector.
Signal name Connection position Fuse No. Capacity
Ignition power supply FUSE BLOCK (J/B) 3 10 A
(+)
(− ) Voltag e
(Approx.)
AFS control unit
Connector Terminal M135 1 Ground Battery voltage
AFS control unit GroundContinuity
Connector Terminal
M135 25 Existed
Revision: 2010 May2011 QX56

EXL-86
< DTC/CIRCUIT DIAGNOSIS >[XENON TYPE]
HEADLAMP (HI) CIRCUIT
HEADLAMP (HI) CIRCUIT
Component Function CheckINFOID:0000000006213955
1.CHECK HEADLAMP (HI) OPERATION
CONSULT-III ACTIVE TEST
1. Select “EXTERNAL LAMPS” of IPDM E/R active test item.
2. With operating the test items, che ck that the headlamp (HI) is turned ON.
NOTE:
ON/OFF is repeated 1 second each.
Is the inspection result normal?
YES >> Headlamp (HI) circuit is normal.
NO >> Refer to EXL-86, "
Diagnosis Procedure".
Diagnosis ProcedureINFOID:0000000006213956
1.CHECK HEADLAMP (HI) OUTPUT VOLTAGE
CONSULT-III ACTIVE TEST
1. Turn ignition switch OFF.
2. Disconnect front combination lamp connector.
3. Turn ignition switch ON.
4. Select “EXTERNAL LAMPS” of IPDM E/R active test item.
5. With operating the test items, check vo ltage between IPDM E/R harness connector and ground.
Is the inspection result normal?
YES >> GO TO 2.
NO >> GO TO 3.
2.CHECK HEADLAMP (HI) OPEN CIRCUIT
1. Turn ignition switch OFF.
2. Disconnect IPDM E/R connector.
3. Check continuity between IPDM E/R harness connec tor and front combination lamp harness connector.
Is the inspection result normal?
YES >> GO TO 5.
NO >> Repair or replace harness.
3.CHECK HEADLAMP (HI) FUSE
1. Turn ignition switch OFF. Hi : Headlamp (HI) ON
Off : Headlamp (HI) OFF
(+)
(− ) Test item Vo l ta g e
(Approx.)
IPDM E/R
Connector Terminal
RH E1549
GroundEXTERNAL
LAMPS Hi Battery voltage
Off 0 V
LH 50 Hi Battery voltage
Off 0 V
IPDM E/R Front combination lamp Continuity
Connector Terminal Connector Terminal
RH E1549 E119
6 Existed
LH 50 E118
Revision: 2010 May2011 QX56

HEADLAMP (HI) CIRCUITEXL-87
< DTC/CIRCUIT DIAGNOSIS > [XENON TYPE]
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EXL
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2. Check that the following fuses are not fusing.
Is the inspection result normal?
YES >> Replace IPDM E/R.
NO >> GO TO 4.
4.CHECK HEADLAMP HIGH (HI) SHORT CIRCUIT
1. Disconnect IPDM E/R connector.
2. Check continuity between IPDM E/R harness connector and ground.
Is the inspection result normal?
YES >> Replace fuse. (Replace IPDM E/R if the fuse is fusing again.)
NO >> Repair or replace harness. And then replace the fuse.
5.CHECK HEADLAMP (HI) GROUND OPEN CIRCUIT
1. Turn ignition switch OFF.
2. Disconnect front combination lamp connector.
3. Check continuity between front combination lamp harness connector and ground.
Is the inspection result normal?
YES >> Replace front combination lamp.
NO >> Repair or replace harness.
Unit Location Fuse No. Capacity
Headlamp HI (RH) IPDM E/R #51
10 A
Headlamp HI (LH) #52
IPDM E/R
GroundContinuity
Connector Terminal
RH E1549
Not existed
LH 50
Front combination lamp
GroundContinuity
Connector Terminal
RH E119 2Existed
LH E118
Revision: 2010 May2011 QX56