ecm INFINITI QX56 2010 Factory Service Manual

HAC-16
< FUNCTION DIAGNOSIS >[AUTOMATIC AIR CONDITIONER]
AUTOMATIC AIR CONDITIONER SYSTEM
Upon receipt of compressor ON signal from ECM, IPDM E/R turns air conditioner relay ON to operate com-
pressor.
Discharge Air Flow (Front)INFOID:0000000005147677
Discharge Air Flow (Rear)INFOID:0000000005147678

Mode door positionAir outlet/distribution
Vent Foot Defroster
95% 5% —
60% 40% —
—7 0% 3 0%
—6 0% 4 0%
—1 0% 9 0%
AWIIA0818ZZ
Revision: April 20092010 QX56

HAC-68
< COMPONENT DIAGNOSIS >[AUTOMATIC AIR CONDITIONER]
MAGNET CLUTCH
MAGNET CLUTCH
System DescriptionINFOID:0000000005147713
SYSTEM DESCRIPTION
The A/C auto amp. controls compressor operation
based on ambient and intake temperature and a signal
from ECM.
Low Temperature Protection Control
The A/C auto amp. will turn the compressor ON or O FF as determined by a signal detected by the intake sen-
sor and the ambient sensor.
When intake air temperature is higher than the preset va lue, the compressor turns ON. The compressor turns
OFF when intake air temperature is lower than the pres et value. That preset value is dependent on the ambi-
ent temperature, refer to the following table.
Magnet Clutch Com ponent Function CheckINFOID:0000000005147714
INSPECTION FLOW
1.CONFIRM SYMPTOM BY PERFORMING OP ERATIONAL CHECK - MAGNET CLUTCH
1. Turn ignition switch ON.
2. Press the A/C switch.
3. Press vent switch ( ).
4. Display shows , A/C. Confirm that the compress or clutch engages (sound or visual inspection). (Dis-
charge air and blower speed will depend on ambi ent, in-vehicle and set temperatures.)
Is the inspection result normal?
YES >> Inspection End.
NO >> Go to diagnosis procedure. Refer to HAC-68, "
Magnet Clutch Diagnosis Procedure".
Magnet Clutch Diagnosis ProcedureINFOID:0000000005147715
Regarding Wiring Diagram information, refer to HAC-91, "Wiring Diagram".
DIAGNOSTIC PROCEDURE FOR MAGNET CLUTCH
Ambient temperature °C ( °F) Compressor ON intake temperature °C ( °F) Compressor OFF intake temperature °C ( °F)
0 (32) 5.5 (42) 5.0 (41)
10 (50) 5.5 (42) 5.0 (41)
20 (68) 5.5 (42) 5.0 (41)
30 (86) 4.0 (39) 3.5 (38)
40 (104) 3.5 (38) 3.0 (37)
50 (122) 3.5 (38) 3.0 (37)
Revision: April 20092010 QX56

MAGNET CLUTCHHAC-71
< COMPONENT DIAGNOSIS > [AUTOMATIC AIR CONDITIONER]
C
D
E
F
G H
J
K L
M A
B
HAC
N
O P
2. Check voltage between ECM harness connector F54 terminal 70 and ground.
Is the inspection result normal?
YES >> GO TO 9.
NO >> Refer to EC-419, "
Diagnosis Procedure".
9.CHECK BCM INPUT (FAN ON) SIGNAL
Check FAN ON/OFF signal. Refer to HAC-20, "
CONSULT-III Function (HVAC)".
Is the inspection result normal?
YES >> GO TO 12.
NO >> GO TO 10.
10.CHECK CIRCUIT CONTINUITY BETW EEN BCM AND A/C AUTO AMP.
1. Turn ignition switch OFF.
2. Disconnect BCM connector and A/C auto amp. connector.
3. Check continuity between BCM harness connector M18 (A) ter- minal 28 and A/C auto amp. harness connector M49 (B) terminal
5.
Is the inspection result normal?
YES >> GO TO 11.
NO >> Repair harness or connector.
11 .CHECK VOLTAGE FOR A/C AUTO AMP. (FAN ON SIGNAL)
1. Reconnect BCM connector and A/C auto amp. connector.
2. Turn ignition switch ON.
3. Check voltage between A/C auto amp. harness connector M49 terminal 5 and ground.
Is the inspection result normal?
YES >> GO TO 12.
NO-1 >> If the voltage is approx. 5V when blower motor is ON, replace A/C auto amp. Refer to VTL-7,
"Removal and Installation".
Te r m i n a l s
ConditionVoltage
(+)
(-)
ECM con-
nector Te r m i n a l N o .
F54 70 Ground A/C switch: ON Approx. 0.36 - 3.88V
LJIA0124E
FRONT BLOWER CONTROL
DIAL ON : FAN ON SIG ON
FRONT BLOWER CONTROL
DIAL OFF : FAN ON SIG OFF
28 - 5 Continuity should exist.
AWIIA0201ZZ
Te r m i n a l s
Condition Voltage
(+)
(-)
A/C auto amp.
connector Te r m i n a l N o .
M49 5GroundA/C switch: ON
Blower motor
operates
Approx. 0V
A/C switch: OFF Approx. 5V
AWIIA0202ZZ
Revision: April 20092010 QX56

HAC-72
< COMPONENT DIAGNOSIS >[AUTOMATIC AIR CONDITIONER]
MAGNET CLUTCH
NO-2 >> If the voltage is approx. 0V when blower motor is OFF, replace BCM. Refer to
BCS-59, "Removal
and Installation".
12.CHECK CAN COMMUNICATION
Check CAN communication. Refer to LAN-4, "
System Description".
•BCM – ECM
• ECM – IPDM E/R
• ECM – A/C auto amp.
Is the inspection result normal?
YES >> Inspection End.
NO >> Repair or replace malfunctioning part(s).
Revision: April 20092010 QX56

INL-72
< ECU DIAGNOSIS >
BCM (BODY CONTROL MODULE)
DTC Inspection Priority Chart
INFOID:0000000005337693
If some DTCs are displayed at the same time, perform inspections one by one based on the following priority
chart.
DTC IndexINFOID:0000000005337694
NOTE: Details of time display
• CRNT: Displays when there is a malfunction now or after returning to the normal condition until turning igni- tion switch OFF → ON again.
• 1 - 39: Displayed if any previous malfunction is present when current condition is normal. It increases like 1
→ 2 → 3...38 → 39 after returning to the normal condition whenever ignition switch OFF → ON. The counter
remains at 39 even if the number of cycles exceeds it. It is counted from 1 again when turning ignition switch
OFF → ON after returning to the normal condition if the malfunction is detected again.
Display contents of CONS ULTFail-safe Cancellation
U1000: CAN COMM CIRCUIT I nhibit engine crankingWhen the BCM re-establishes communication with the other mod-
ules.
Priority
DTC
1 • U1000: CAN COMM CIRCUIT
2 • B2190: NATS ANTENNA AMP
• B2191: DIFFERENCE OF KEY
• B2192: ID DISCORD BCM-ECM
• B2193: CHAIN OF BCM-ECM
• B2013: STRG COMM 1
• B2552: INTELLIGENT KEY
• B2590: NATS MALFUNCTION
3 • C1729: VHCL SPEED SIG ERR
• C1735: IGNITION SIGNAL
4 • C1708: [NO DATA] FL
• C1709: [NO DATA] FR
• C1710: [NO DATA] RR
• C1711: [NO DATA] RL
• C1712: [CHECKSUM ERR] FL
• C1713: [CHECKSUM ERR] FR
• C1714: [CHECKSUM ERR] RR
• C1715: [CHECKSUM ERR] RL
• C1716: [PRESSDATA ERR] FL
• C1717: [PRESSDATA ERR] FR
• C1718: [PRESSDATA ERR] RR
• C1719: [PRESSDATA ERR] RL
• C1720: [CODE ERR] FL
• C1721: [CODE ERR] FR
• C1722: [CODE ERR] RR
• C1723: [CODE ERR] RL
• C1724: [BATT VOLT LOW] FL
• C1725: [BATT VOLT LOW] FR
• C1726: [BATT VOLT LOW] RR
• C1727: [BATT VOLT LOW] RL
CONSULT display
Fail-safeIntelligent Key
warning lamp ON Tire pressure
monitor warning lamp ON Reference page
No DTC is detected.
further testing
may be required. ————
U1000: CAN COMM CIRCUIT ———BCS-32
B2190: NATS ANTENNA AMP ———SEC-31
Revision: April 20092010 QX56

BCM (BODY CONTROL MODULE)INL-73
< ECU DIAGNOSIS >
C
DE
F
G H
I
J
K
M A
B
INL
N
O P
B2191: DIFFERENCE OF KEY ———SEC-34
B2192: ID DISCORD BCM-ECM ———SEC-35
B2193: CHAIN OF BCM-ECM ———SEC-37
B2552: INTELLIGENT KEY ———SEC-39
B2590: NATS MALFUNCTION ———SEC-40
C1708: [NO DATA] FL ———WT-14
C1709: [NO DATA] FR ———WT-14
C1710: [NO DATA] RR ———WT-14
C1711: [NO DATA] RL ———WT-14
C1712: [CHECKSUM ERR] FL ———WT-16
C1713: [CHECKSUM ERR] FR ———WT-16
C1714: [CHECKSUM ERR] RR ———WT-16
C1715: [CHECKSUM ERR] RL ———WT-16
C1716: [PRESSDATA ERR] FL ———WT-18
C1717: [PRESSDATA ERR] FR ———WT-18
C1718: [PRESSDATA ERR] RR ———WT-18
C1719: [PRESSDATA ERR] RL ———WT-18
C1720: [CODE ERR] FL ———WT-16
C1721: [CODE ERR] FR ———WT-16
C1722: [CODE ERR] RR ———WT-16
C1723: [CODE ERR] RL ———WT-16
C1724: [BATT VOLT LOW] FL ———WT-16
C1725: [BATT VOLT LOW] FR ———WT-16
C1726: [BATT VOLT LOW] RR ———WT-16
C1727: [BATT VOLT LOW] RL ———WT-16
C1729: VHCL SPEED SIG ERR ———WT-19
C1735: IGNITION SIGNAL ———WT-20
CONSULT display Fail-safeIntelligent Key
warning lamp ON Tire pressure
monitor warning
lamp ON Reference page
Revision: April 20092010 QX56

LAN-2
MAIN LINE BETWEEN TCM AND LASER
CIRCUIT .............................................................
63
Diagnosis Procedure ........................................... ...63
MAIN LINE BETWEEN LASER AND ICC CIR-
CUIT ...................................................................
64
Diagnosis Procedure ........................................... ...64
MAIN LINE BETWEEN ICC AND ADP CIR-
CUIT ...................................................................
65
Diagnosis Procedure ........................................... ...65
MAIN LINE BETWEEN ADP AND AV CIR-
CUIT ...................................................................
66
Diagnosis Procedure ........................................... ...66
MAIN LINE BETWEEN AV AND DLC CIR-
CUIT ...................................................................
67
Diagnosis Procedure ........................................... ...67
MAIN LINE BETWEEN DLC AND M&A CIR-
CUIT ...................................................................
68
Diagnosis Procedure ........................................... ...68
MAIN LINE BETWEEN M&A AND ABS CIR-
CUIT ...................................................................
69
Diagnosis Procedure ........................................... ...69
MAIN LINE BETWEEN M&A AND 4WD CIR-
CUIT ...................................................................
70
Diagnosis Procedure ........................................... ...70
MAIN LINE BETWEEN 4WD AND ABS CIR-
CUIT ...................................................................
71
Diagnosis Procedure ........................................... ...71
ECM BRANCH LINE CIRCUIT ..........................72
Diagnosis Procedure ........................................... ...72
TCM BRANCH LINE CIRCUIT ..........................73
Diagnosis Procedure ........................................... ...73
LASER BRANCH LINE CIRCUIT ......................74
Diagnosis Procedure ............................................ ...74
ICC BRANCH LINE CIRCUIT ............................75
Diagnosis Procedure ............................................ ...75
ADP BRANCH LINE CIRCUIT ..........................76
Diagnosis Procedure ............................................ ...76
AV BRANCH LINE CIRCUIT .............................77
Diagnosis Procedure ............................................ ...77
BCM BRANCH LINE CIRCUIT ..........................78
Diagnosis Procedure ............................................ ...78
DLC BRANCH LINE CIRCUIT ..........................79
Diagnosis Procedure ............................................ ...79
HVAC BRANCH LINE CIRCUIT ........................80
Diagnosis Procedure ............................................ ...80
I-KEY BRANCH LINE CIRCUIT ........................81
Diagnosis Procedure ............................................ ...81
M&A BRANCH LINE CIRCUIT ..........................82
Diagnosis Procedure ............................................ ...82
STRG BRANCH LINE CIRCUIT ........................83
Diagnosis Procedure ............................................ ...83
4WD BRANCH LINE CIRCUIT ..........................84
Diagnosis Procedure ............................................ ...84
ABS BRANCH LINE CIRCUIT ..........................85
Diagnosis Procedure ............................................ ...85
IPDM-E BRANCH LINE CIRCUIT .....................86
Diagnosis Procedure ............................................ ...86
CAN COMMUNICATION CIRCUIT ...................87
Diagnosis Procedure ............................................ ...87
Revision: April 20092010 QX56

LAN-8
< FUNCTION DIAGNOSIS >[CAN FUNDAMENTAL]
TROUBLE DIAGNOSIS
Example: TCM branch line open circuit
Example: Data link connector branch line open circuit
SKIB8738E
Unit name
Symptom
ECM Engine torque limiting is affected, and shift harshness increases.
BCM Reverse warning chime does not sound.
EPS control unit Normal operation.
Combination meter • Shift position indicator and OD OFF indicator turn OFF.
• Warning lamps turn ON.
ABS actuator and electric unit (control unit) Normal operation.
TCM No impact on operation.
IPDM E/R Normal operation.
SKIB8739E
Revision: April 20092010 QX56

LAN
TROUBLE DIAGNOSISLAN-9
< FUNCTION DIAGNOSIS > [CAN FUNDAMENTAL]
C
D
E
F
G H
I
J
K L
B A
O P
N
NOTE:
• When data link connector branch line is open, transmi
ssion and reception of CAN communication signals
are not affected. Therefore, no symptoms occur. However, be sure to repair malfunctioning circuit.
• When data link connector branch line is open, “ECU list ” displayed on the CONSULT-III “CAN DIAG SUP-
PORT MNTR” may be the same as when the CAN comm unication line has short-circuit. However, symp-
toms differ depending on the case. See below chart for the differences.
Example: Main Line Between Data Link Connector and ABS Actuator and Electr ic Unit (Control Unit) Open Circuit
Unit name Symptom
ECM
Normal operation.
BCM
EPS control unit
Combination meter
ABS actuator and electric
unit (control unit)
TCM
IPDM E/R
“ECU list” on the “CAN DIAG SUPPORT MNTR”(CONSULT-III) Difference of symptom
Data link connector branch line open circuit All Diag on CAN units are not
indicated.Normal operation.
CAN-H, CAN-L harness short-circuit Most of the units which are connected to the CAN
communication system enter fail-safe mode or are
deactivated.
SKIB8740E
Unit name
Symptom
ECM Engine torque limiting is affected, and shift harshness increases.
BCM • Reverse warning chime does not sound.
• The front wiper moves under continuous operation mode even though the front wip-
er switch being in the intermittent position.
EPS control unit The steering effort increases.
Combination meter • The shift position indicator and OD OFF indicator turn OFF.
• The speedometer is inoperative.
• The odo/trip meter stops.
ABS actuator and electric unit (control unit) Normal operation.
Revision: April 20092010 QX56

LAN-10
< FUNCTION DIAGNOSIS >[CAN FUNDAMENTAL]
TROUBLE DIAGNOSIS
Example: CAN-H, CAN-L Harness Short Circuit
TCM
No impact on operation.
IPDM E/R When the ignition switch is ON,
• The headlamps (Lo) turn ON.
• The cooling fan continues to rotate.
Unit name
Symptom
SKIB8741E
Unit nameSymptom
ECM • Engine torque limiting is affected, and shift harshness increases.
• Engine speed drops.
BCM • Reverse warning chime does not sound.
• The front wiper moves under continuous operation mode even though the front
wiper switch being in the intermittent position.
• The room lamp does not turn ON.
• The engine does not start (if an error or malfunction occurs while turning the igni- tion switch OFF.)
• The steering lock does not release (if an error or malfunction occurs while turning the ignition switch OFF.)
EPS control unit The steering effort increases.
Combination meter • The tachometer and the speedometer do not move.
• Warning lamps turn ON.
• Indicator lamps do not turn ON.
ABS actuator and electric unit (control unit) Normal operation.
TCM No impact on operation.
IPDM E/R When the ignition switch is ON,
• The headlamps (Lo) turn ON.
• The cooling fan continues to rotate.
Revision: April 20092010 QX56