2011 INFINITI QX56 ignition

SBC-50
< DTC/CIRCUIT DIAGNOSIS >
B2470 SYS HEAT PROTC DR
B2470 SYS HEAT PROTC DR
DescriptionINFOID:0000000006237924
When fastening and unfastening seat belt or opening and closing door is repeated continuously for a short
period of time, the system temporarily deactivates the retracting function of seat belt to prevent excessive
heating. The system recovers automatically.
DTC LogicINFOID:0000000006237925
DTC DETECTION LOGIC
DTC CONFIRMATION PROCEDURE
1.SELF-DIAGNOSIS WITH PRE-CRASH SEAT BELT CONTROL UNIT
1. Turn ignition switch ON.
2. Check “Self-diagnostic result” with CONSULT-III.
Is DTC detected?
YES >> Refer to SBC-50, "Diagnosis Procedure".
NO >> INSPECTION END
Diagnosis ProcedureINFOID:0000000006237926
1.CHECK THE VEHICLE CONDITION WITH CONSULT-III DATA MONITOR
1. Check “HEAT PROTC LH” in “D ATA MONITOR” with CONSULT-III.
2. Wait until “OFF” appears.
3. Perform the “self-diagnosis result” with CONSULT-III, after performing the check.
4. Touch “ERASE”.
5. Perform DTC Confirmation Procedure. Refer to SBC-50, "
DTC Logic".
Is DTC B2470 displayed again?
YES >> GO TO 2.
NO >> INSPECTION END
2.CHECK INTERMITTENT INCIDENT
Refer to GI-40, "
Intermittent Incident".
>> INSPECTION END
DTC No. Self-diagnosis item DTC Detection Condition Possible causes
B2470 SYS HEAT PROTC DR Deactivate s to prevent excessive heating Comfort function activates continuously in a
short period of time.
Revision: 2010 May2011 QX56

B2471 SYS HEAT PROTC ASSBC-51
< DTC/CIRCUIT DIAGNOSIS >
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B2471 SYS HEAT PROTC AS
DescriptionINFOID:0000000006237927
When fastening and unfastening seat belt or opening and cl osing door is repeated continuously for a short
period of time, the system temporar ily deactivates the retracting function of seat belt to prevent excessive
heating. The system recovers automatically.
DTC LogicINFOID:0000000006237928
DTC DETECTION LOGIC
DTC CONFIRMATION PROCEDURE
1.SELF-DIAGNOSIS WITH PRE-CRASH SEAT BELT CONTROL UNIT
1. Turn ignition switch ON.
2. Check “Self-diagnostic result” with CONSULT-III.
Is DTC detected?
YES >> Refer to SBC-51, "Diagnosis Procedure".
NO >> INSPECTION END
Diagnosis ProcedureINFOID:0000000006237929
1.CHECK THE VEHICLE CONDITION WITH CONSULT-III DATA MONITOR
1. Check “HEAT PROTC RH” in “DATA MONITOR” with CONSULT-III.
2. Wait until “OFF” appears.
3. Perform the “self-diagnosis results” wit h CONSULT-III, after performing the check.
4. Touch “ERASE”.
5. Perform DTC Confirmation Procedure. Refer to SBC-51, "
DTC Logic".
Is DTC B2471 displayed again?
YES >> GO TO 2.
NO >> INSPECTION END
2.CHECK INTERMITTENT INCIDENT
Refer to GI-40, "
Intermittent Incident".
>> INSPECTION END
DTC No. Self-diagnosis item DTC Detection Condition Possible causes
B2471 SYS HEAT PROTC AS Deactivate s to prevent excessive heating Belt retracting function activates continuously in
the short period of time
Revision: 2010 May2011 QX56

SBC-52
< DTC/CIRCUIT DIAGNOSIS >
POWER SUPPLY AND GROUND CIRCUIT
POWER SUPPLY AND GROUND CIRCUIT
Diagnosis ProcedureINFOID:0000000006237930
1.CHECK GROUND CIRCUIT
1. Turn ignition switch OFF.
2. Disconnect pre-crash seat belt control unit (driver side and passenger side) harness connector.
3. Check continuity between pre-crash seat belt c ontrol unit (driver side and passenger side) harness con-
nector and ground.
Is the measurement value normal?
YES >> GO TO 2.
NO >> Repair or replace harness or connector.
2.CHECK POWER SUPPLY CIRCUIT-I
Check voltage between pre-crash seat belt control unit (driver side and passenger side) harness connector
and ground.
Is the measurement value normal?
YES >> INSPECTION END
NO >> GO TO 3.
3.CHECKPOWER SUPPLY CIRCUIT-II
1. Disconnect fuse block (J/B) harness connector.
2. Check continuity between pre-crash seat belt c ontrol unit (driver side and passenger side) harness con-
nector and fuse block (J/B) harness connector.
3. Check continuity between pre-crash seat belt c ontrol unit (driver side and passenger side) harness con-
nector and ground.
Is the measurement value normal?
YES >> Check 10 A fuse (No. 6).
NO >> Repair or replace harness or connector.
Pre-crash seat belt control unit GroundContinuity
Connector Terminal
B9 (Driver side) 18
Existed
20
B231 (Passenger side) 18
20
Pre-crash seat belt control unit
GroundVo l ta g e
(Approx.)
Connector Terminal
B9 (Driver side) 1 Battery voltage
B231 (Passenger side)
Pre-crash seat belt control unit Fuse block (J/B) Continuity
Connector Terminal Connector Terminal
B9 (Driver side) 1 M2 6B Existed
B231 (Passenger side)
Pre-crash seat belt control unit GroundContinuity
Connector Terminal
B9 (Driver side) 1 Not existed
B231 (Passenger side)
Revision: 2010 May2011 QX56

SEAT BELT BUCKLE SWITCH (DRIVER SIDE)
SBC-53
< DTC/CIRCUIT DIAGNOSIS >
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SEAT BELT BUCKLE SW ITCH (DRIVER SIDE)
Component Function CheckINFOID:0000000006237931
1.CHECK SEAT BELT WARNING LAMP FUNCTION
1. Turn ignition switch ON.
2. Sits in the passenger seat.
3. Fasten the seat belt (passenger side).
4. Check seat belt warning lamp function.
Is the inspection results normal?
YES >> GO TO 2.
NO >> Check seat belt warning lamp circuit. Refer to SBC-57, "
Diagnosis Procedure".
2.CHECK PRE-CRASH SEAT BELT CONTROL UNIT (DRIVER SIDE) FUNCTION
With CONSULT-III
When checking “BUCKLE SW LH” on DATA MONITOR scr een, check that ON/OFF display changes synchro-
nized with the insertion operat ion to the seat belt buckle.
Is the inspection result normal?
YES >> Seat belt buckle switch (driver side) circuit is normal.
NO >> Check seat belt buckle switch (driver side). Refer to SBC-53, "
Diagnosis Procedure".
Diagnosis ProcedureINFOID:0000000006237932
1.CHECK PRE-CRASH SEAT BELT CONTROL UNIT (DRIVER SIDE) OUTPUT SIGNAL
1. Turn ignition switch OFF.
2. Disconnect seat belt assembly (driver side) harness connector.
3. Turn ignition switch ON.
4. Check voltage between seat belt assembly (driver side) harness connector and ground.
Is the inspection result normal?
YES >> GO TO 3.
NO >> GO TO 2.
2.CHECK SEAT BELT ASSEMB LY (DRIVER SIDE) CIRCUIT
1. Turn ignition switch OFF.
2. Disconnect pre-crash seat belt control unit (driver side) harness connector.
3. Check continuity between pre-crash seat belt cont rol unit (driver side) harness connector and seat belt
assembly (driver side) harness connector.
Condition Seat belt warning lamp
Seat belt (driver side) is fastened Not illuminated
Seat belt (driver side) is unfastened Illuminated
Monitor item Condition
BUCKLE SW LH When driver side seat belt is not fastened: OFF
When driver side seat belt is fastened: ON
(+)
(–)Voltage (V)
(Approx.)
Seat belt assembly (driver side)
Connector Terminal B76 5 Ground 5
Pre-crash seat belt control unit (driver side) Seat belt assembly (driver side) Continuity
Connector Terminal Connector Terminal
B9 6 B76 5 Existed
Revision: 2010 May2011 QX56

SBC-54
< DTC/CIRCUIT DIAGNOSIS >
SEAT BELT BUCKLE SWITCH (DRIVER SIDE)
4. Check continuity between pre-crash seat belt control unit (driver side) harness connector and ground.
Is the inspection result normal?
YES >> Replace pre-crash seat belt control unit (driver side). Refer to SB-6, "SEAT BELT RETRACTOR :
Removal and Installation".
NO >> Repair or replace harness or connector.
3.CHECK SEAT ASSEMBLY SWITCH GROUND CIRCUIT
Check continuity between seat belt assembly (driver side) and ground.
Is the inspection result normal?
YES >> GO TO 4.
NO >> Repair or replace harness or connector.
4.CHECK SEAT BELT ASSEMBLY (DRIVER SIDE)
Check seat belt assembly (driver side). Refer to SBC-54, "
Component Inspection [Seat Belt Assembly (Driver
Side)]".
Is the inspection result normal?
YES >> Check intermittent incident. Refer to GI-40, "Intermittent Incident".
NO >> Replace seat belt assembly (driver side). Refer to SB-6, "
SEAT BELT RETRACTOR : Removal
and Installation".
Component Inspection [Seat Belt Assembly (Driver Side)]INFOID:0000000006237933
1.CHECK SEAT BELT ASSEMBLY (DRIVER SIDE)
1. Turn ignition switch OFF.
2. Disconnect seat belt assembly (driver side) harness connector.
3. Check continuity between seat belt assembly (driver side) terminals.
Is the inspection result normal?
YES >> INSPECTION END
NO >> Replace seat belt assembly (driver side). Refer to SB-6, "
SEAT BELT RETRACTOR : Removal
and Installation".
Pre-crash seat belt control unit (driver side)
GroundContinuity
Connector Terminal
B9 6 Not existed
Seat belt assembly (driver side) GroundContinuity
Connector Terminal
B76 4 Existed
Seat belt assembly (driver side) Condition Continuity
Te r m i n a l
3 4When driver side seat belt is fastened Not existed
When driver side seat belt is not fastened Existed
5 When driver side seat belt is fastened Existed
When driver side seat belt is not fastened Not existed
Revision: 2010 May2011 QX56

SEAT BELT BUCKLE SWITCH (PASSENGER SIDE)SBC-55
< DTC/CIRCUIT DIAGNOSIS >
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SEAT BELT BUCKLE SW ITCH (PASSENGER SIDE)
Component Function CheckINFOID:0000000006237934
1.CHECK SEAT BELT WARNING LAMP FUNCTION
1. Turn ignition switch ON.
2. Sits in the passenger seat.
3. Fasten the seat belt (passenger side).
4. Check seat belt warning lamp function.
Is the inspection results normal?
YES >> GO TO 2.
NO >> Check seat belt warning lamp circuit. Refer to SBC-57, "
Diagnosis Procedure".
2.CHECK PRE-CRASH SEAT BELT CONTROL UNIT FUNCTION
With CONSULT-III
When checking “BUCKLE SW RH” on DATA MONITOR scr een, check that ON/OFF display changes are syn-
chronized with the insertion operation to the seat belt buckle.
Is the inspection result normal?
YES >> Seat belt buckle switch (passenger side) circuit is normal.
NO >> Check seat belt buckle switch (passenger side). Refer to SBC-55, "
Diagnosis Procedure".
Diagnosis ProcedureINFOID:0000000006237935
1.CHECK PRE-CRASH SEAT BELT CONTROL UNIT (PASSENGER SIDE) OUTPUT SIGNAL
1. Turn ignition switch OFF.
2. Disconnect seat belt assembly (passenger side) harness connector.
3. Turn ignition switch ON.
4. Check voltage between seat belt assembly (passenger side) and ground.
Is the inspection result normal?
YES >> GO TO 3.
NO >> GO TO 2.
2.CHECK SEAT BELT ASSEMBLY (PASSENGER SIDE) CIRCUIT
1. Turn ignition switch OFF.
2. Disconnect pre-crash seat belt contro l unit (passenger side) harness connector.
3. Check continuity between pre-crash seat belt c ontrol unit (passenger side) harness connector and seat
belt assembly (passenger side) harness connector.
Condition Seat belt warning lamp
Seat belt (driver side) is fastened Not illuminated
Seat belt (driver side) is unfastened Illuminated
Monitor item Condition
BUCKLE SW RH When driver side seat belt is not fastened: OFF
When driver side seat belt is fastened: ON
(+)
(–)Voltage (V)
(Approx.)
Seat belt assembly (passenger side)
Connector Terminal B245 5 Ground 5
Pre-crash seat belt control unit (passenger side) Seat belt assembly (passenger side) Continuity
Connector Terminal Connector Terminal
B2316B2455Existed
Revision: 2010 May2011 QX56

SBC-56
< DTC/CIRCUIT DIAGNOSIS >
SEAT BELT BUCKLE SWITCH (PASSENGER SIDE)
4. Check continuity between pre-crash seat belt control unit (passenger side) harness connector and
ground.
Is the inspection result normal?
YES >> Replace pre-crash seat belt control unit (passenger side). Refer to SB-6, "SEAT BELT RETRAC-
TOR : Removal and Installation".
NO >> Repair or replace harness or connector.
3.CHECK SEAT BELT ASSEMBLY (PA SSENGER SIDE) GROUND CIRCUIT
Check continuity between seat belt assembly (passenger side) and ground.
Is the inspection result normal?
YES >> GO TO 4.
NO >> Repair or replace harness or connector.
4.CHECK SEAT BELT ASSEMBLY (PASSENGER SIDE)
Check seat belt assembly (passenger side). Refer to SBC-56, "
Component Inspection [Seat Belt Assembly
(Passenger Side)]".
Is the inspection result normal?
YES >> Check intermittent incident. Refer to GI-40, "Intermittent Incident".
NO >> Replace seat belt assembly (passenger side). Refer to SB-6, "
SEAT BELT RETRACTOR :
Removal and Installation".
Component Inspection [Seat Belt Assembly (Passenger Side)]INFOID:0000000006237936
1.CHECK SEAT BELT ASSEMBLY (PASSENGER SIDE)
1. Turn ignition switch OFF.
2. Disconnect seat belt assembly (passenger side) harness connector.
3. Check continuity between seat belt assembly (passenger side) terminals.
Is the inspection result normal?
YES >> INSPECTION END
NO >> Replace seat belt assembly (passenger side). Refer to SB-6, "
SEAT BELT RETRACTOR :
Removal and Installation".
Pre-crash seat belt control unit (passenger side)
GroundContinuity
Connector Terminal
B231 6 Not existed
Seat belt assembly (passenger side) GroundContinuity
Connector Terminal
B245 4 Existed
Seat belt assembly (passenger side) Condition Continuity
Te r m i n a l
3 4When passenger side seat belt is fastened Not existed
When passenger side seat belt is not fastened Existed
5 When passenger side seat belt is fastened Existed
When passenger side seat belt is not fastened Not existed
Revision: 2010 May2011 QX56

SEAT BELT WARNING LAMP CIRCUITSBC-57
< DTC/CIRCUIT DIAGNOSIS >
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SEAT BELT WARNING LAMP CIRCUIT
Component Function CheckINFOID:0000000006237937
1.CHECK SEAT BELT WARNI NG LAMP FUNCTION-I
1. Turn ignition switch ON.
2. Check seat belt warning lamp function.
Is the inspection results normal?
YES >> GO TO 2.
NO >> Check combination meter circuit. Refer to MWI-57, "
Work flow".
2.CHECK SEAT BELT WARNING LAMP FUNCTION-II
1. Sits in the passenger seat.
2. Fasten the seat belt (passenger side).
3. Check seat belt warning lamp function.
Is the inspection results normal?
YES >> Seat belt warning lamp circuit is normal.
NO >> Check seat belt warning lamp circuit. Refer to SBC-57, "
Diagnosis Procedure".
Diagnosis ProcedureINFOID:0000000006237938
WARNING:
 Before servicing, turn ignition switch OFF, disconnect battery negative terminal and wait at least 3
minutes. (To discharge backup capacitor.)
 Never use unspecified tester or other measuring device.
1.CHECK SEAT BELT ASSEMBLY (PASSENGER SIDE) CIRCUIT-I
1. Turn ignition switch OFF.
2. Disconnect air bag diagnosis sensor unit harness connec tor and seat belt assembly (passenger side) har-
ness connector.
3. Check continuity between air bag diagnosis sensor unit harness connector and seat belt assembly (pas-
senger side) harness connector.
4. Check continuity between air bag diagnosis sensor unit harness connector and ground.
Is the inspection result normal?
YES >> GO TO 2.
NO >> Replace harness or connector.
2.CHECK SEAT BELT ASSEMBLY (PASSENGER SIDE) CIRCUIT-II
Check continuity between seat belt assemb ly (passenger side) harness connector and ground.
Condition Seat belt warning lamp
Seat belt (driver side) is fastened Not illuminated
Seat belt (driver side) is unfastened Illuminated
Condition Seat belt warning lamp
Seat belt (passenger side) is fastened Not illuminated
Seat belt (passenger side) is unfastened Illuminated
Air bag diagnosis sensor unit Seat belt assembly (passenger side) Continuity
Connector Terminal Connector Terminal
B228 29 B245 3 Existed
Air bag diagnosis sensor unit GroundContinuity
Connector Terminal
B228 29 Not existed
Revision: 2010 May2011 QX56