2007 INFINITI QX56 air condition

DTC P1554 BATTERY CURRENT SENSOR
EC-501
< SERVICE INFORMATION >
C
D
E
F
G
H
I
J
K
L
MA
EC
N
P O
DTC P1554 BATTERY CURRENT SENSOR
Component DescriptionINFOID:0000000003532032
The power generation voltage variable control enables fuel con-
sumption to be decreased by reducing the engine load which is
caused by the power generation of the generator. The battery cur-
rent sensor (1) is installed to the battery cable at the negative termi-
nal. The sensor measures the charging/discharging current of the
battery. Based on the sensor signal, ECM judges whether or not the
power generation voltage variable control is performed. When per-
forming the power generation voltage variable control, ECM calcu-
lates the target power generation voltage based on the sensor
signal. And ECM sends the calculated value as the power genera-
tion command value to IPDM E/R. For the details of the power gen-
eration voltage variable control, refer to SC section.
CAUTION:
Do not connect the electrical component or the ground wire directly to the battery terminal. The con-
nection causes the malfunction of the power generation voltage variable control, and then the battery
discharge may occur.
CONSULT-II Reference Value in Data Monitor ModeINFOID:0000000003532033
Specification data are reference values.
*: Before measuring the terminal voltage, confirm that the battery is fully charged. Refer to SC-4, "How to Handle Battery".
On Board Diagnosis LogicINFOID:0000000003532034
The MIL will not light up for this self-diagnosis.
NOTE:
If DTC P1554 is displayed with DTC P0643, first perform the trouble diagnosis for DTC P0643. Refer to
EC-447
.
Overall Function CheckINFOID:0000000003532035
Use this procedure to check the overall function of the battery current sensor circuit. During this check, a 1st
trip DTC might not be confirmed.
TESTING CONDITION:
•Before performing the following procedure, confirm that battery voltage is more than 12.8V at idle.
•Before performing the following procedure, confirm that all load switches and A/C switch are turned
OFF.
WITH CONSULT-II
1. Start engine and let it idle.
BBIA0744E
MONITOR ITEM CONDITION SPECIFICATION
BAT CUR SEN• Engine speed: Idle
• Battery: Fully charged*
• Selector lever: P or N
• Air conditioner switch: OFF
•No loadApprox. 2,600 - 3,500mV
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P1554
1554Battery current sensor performanceThe output voltage of the battery current
sensor is lower than the specified value
while the battery voltage is high enough.• Harness or connectors
(The sensor circuit is open or shorted.)
• Battery current sensor

EC-504
< SERVICE INFORMATION >
DTC P1554 BATTERY CURRENT SENSOR
*: Before measuring the terminal voltage, confirm that the battery is fully charged. Refer to SC-4, "How to Handle Battery".
Diagnosis ProcedureINFOID:0000000003532037
1.CHECK GROUND CONNECTIONS
1. Turn ignition switch OFF.
2. Loosen and retighten ground screws on the body.
Refer to EC-143, "
Ground Inspection".
OK or NG
OK >> GO TO 2.
NG >> Repair or replace ground connections.
2.CHECK BATTERY CURRENT SENSOR POWER SUPPLY CIRCUIT
1. Disconnect battery current sensor (1) harness connector.
2. Turn ignition switch ON.
TER-
MI-
NAL
NO.WIRE
COLORITEM CONDITION DATA (DC Voltage)
49 R/YSensor power supply
(Battery current sensor)[Ignition switch: ON]Approximately 5V
67 BSensor ground
(Battery current sensor)[Engine is running]
•Warm-up condition
• Idle speedApproximately 0V
71 R Battery current sensor[Engine is running]
• Battery: Fully charged*
• Idle speedApproximately 2.6 - 3.5V
BBIA0354E
BBIA0744E

EC-510
< SERVICE INFORMATION >
DTC P1564 ICC STEERING SWITCH
Diagnosis Procedure
INFOID:0000000003532044
1.CHECK GROUND CONNECTIONS
1. Turn ignition switch OFF.
2. Loosen and retighten three ground screws on the body.
Refer to EC-143, "
Ground Inspection".
OK or NG
OK >> GO TO 2.
NG >> Repair or replace ground connections.
2.CHECK ICC STEERING SWITCH CIRCUIT
With CONSULT-II
1. Turn ignition switch ON.
2. Select “MAIN SW”, “CANCEL SW”, “RESUME/ACC SW”, “SET
SW” and “DIST SW” in “DATA MONITOR” mode with CON-
SULT-II.
3. Check each item indication under the following conditions.
TER-
MI-
NAL
NO.WIRE
COLORITEM CONDITION DATA (DC Voltage)
67 B Sensor ground[Engine is running]
•Warm-up condition
• Idle speedApproximately 0V
99 G/Y ICC steering switch[Ignition switch: ON]
• ICC steering switch: OFFApproximately 4.3V
[Ignition switch: ON]
• MAIN switch: PressedApproximately 0V
[Ignition switch: ON]
• CANCEL switch: PressedApproximately 1.3V
[Ignition switch: ON]
• RESUME/ACCELERATE switch: PressedApproximately 3.7V
[Ignition switch: ON]
• SET/COAST switch: PressedApproximately 3V
[Ignition switch: ON]
• DISTANCE switch: PressedApproximately 2.2V
BBIA0354E
Switch Monitor item Condition Indication
MAIN switch MAIN SWPressed ON
Released OFF
CANCEL switch CANCEL SWPressed ON
Released OFF
RESUME/ACCELERATE
switchRESUME/ACC SWPressed ON
Released OFF
MBIB0064E

DTC P1564 ICC STEERING SWITCH
EC-511
< SERVICE INFORMATION >
C
D
E
F
G
H
I
J
K
L
MA
EC
N
P O
Without CONSULT-II
1. Turn ignition switch ON.
2. Check voltage between ECM terminal 99 and ground with press-
ing each button.
OK or NG
OK >> GO TO 8.
NG >> GO TO 3.
3.CHECK ICC STEERING SWITCH GROUND CIRCUIT FOR OPEN AND SHORT
1. Turn ignition switch OFF.
2. Disconnect ECM harness connector.
3. Disconnect combination switch harness connector.
4. Check harness continuity between combination switch terminal 15 and ECM terminal 67.
Refer to Wiring Diagram.
5. Also check harness for short to ground and short to power.
OK or NG
OK >> GO TO 5.
NG >> GO TO 4.
4.DETECT MALFUNCTIONING PART
Check the following.
• Harness connectors M31, E152
• Harness connectors E5, F14
• Combination switch (spiral cable)
• Harness for open and short between ECM and combination switch
>> Repair open circuit or short to ground or short to power in harness or connectors.
5.CHECK ICC STEERING SWITCH INPUT SIGNAL CIRCUIT FOR OPEN AND SHORT
1. Check harness continuity between ECM terminal 99 and combination switch terminal 14.
Refer to Wiring Diagram.
SET/COAST switch SET SWPressed ON
Released OFF
DISTANCE switch DIST SWPressed ON
Released OFF Switch Monitor item Condition Indication
Switch Condition Voltage [V]
MAIN switchPressed Approx. 0
Released Approx. 4.3
CANCEL switchPressed Approx. 1.3
Released Approx. 4.3
RESUME/ACCELERATE
switchPressed Approx. 3.7
Released Approx. 4.3
SET/COAST switchPressed Approx. 3.0
Released Approx. 4.3
DISTANCE switchPressed Approx. 2.2
Released Approx. 4.3
PBIB0311E
Continuity should exist.
Continuity should exist.

EC-512
< SERVICE INFORMATION >
DTC P1564 ICC STEERING SWITCH
2. Also check harness for short to ground and short to power.
OK or NG
OK >> GO TO 7.
NG >> GO TO 6.
6.DETECT MALFUNCTIONING PART
Check the following.
• Harness connectors M31, E152
• Combination switch (spiral cable)
• Harness for open and short between ECM and combination switch
>> Repair open circuit or short to ground or short to power in harness or connectors.
7.CHECK ICC STEERING SWITCH
Refer to EC-512, "
Component Inspection".
OK or NG
OK >> GO TO 8.
NG >> Replace ICC steering switch.
8.CHECK INTERMITTENT INCIDENT
Refer to EC-138
.
>>INSPECTION END
Component InspectionINFOID:0000000003532045
ICC STEERING SWITCH
1. Disconnect combination switch (spiral cable) harness connector M102.
2. Check continuity between combination switch terminals 1 and 2
with pushing each switch.
If NG, replace ICC steering switch.
Switch Condition Resistance [Ω]
MAIN switchPressed Approx. 0
Released Approx. 5,500
CANCEL switchPressed Approx. 310
Released Approx. 5,500
RESUME/ACCELERATE
switchPressed Approx. 2,600
Released Approx. 5,500
SET/COAST switchPressed Approx. 1,400
Released Approx. 5,500
DISTANCE switchPressed Approx. 740
Released Approx. 5,500
PBIB0967E

EC-516
< SERVICE INFORMATION >
DTC P1564 ASCD STEERING SWITCH
Diagnosis Procedure
INFOID:0000000003532051
1.CHECK GROUND CONNECTIONS
1. Turn ignition switch OFF.
2. Loosen and retighten three ground screws on the body.
Refer to EC-143, "
Ground Inspection".
OK or NG
OK >> GO TO 2.
NG >> Repair or replace ground connections.
2.CHECK ASCD STEERING SWITCH CIRCUIT
With CONSULT-II
1. Turn ignition switch ON.
2. Select “MAIN SW”, “CANCEL SW”, RESUME/ACC SW” and “SET SW” in “DATA MONITOR” mode with
CONSULT-II.
3. Check each item indication under the following conditions.
TER-
MI-
NAL
NO.WIRE
COLORITEM CONDITION DATA (DC Voltage)
67 B Sensor ground[Engine is running]
•Warm-up condition
• Idle speedApproximately 0V
99 G/Y ASCD steering switch[Ignition switch: ON]
• ASCD steering switch: OFFApproximately 4V
[Ignition switch: ON]
• MAIN switch: ONApproximately 0V
[Ignition switch: ON]
• CANCEL switch: ONApproximately 1V
[Ignition switch: ON]
• RESUME/ACCELERATTTE switch: ONApproximately 3V
[Ignition switch: ON]
• SET/COAST switch: ONApproximately 2V
BBIA0354E
Switch Monitor item Condition Indication
MAIN switch MAIN SWPressed ON
Released OFF
CANCEL switch CANCEL SWPressed ON
Released OFF
RESUME/ACCELERATE
switchRESUME/ACC SWPressed ON
Released OFF
SET/COAST switch SET SWPressed ON
Released OFF
SEC006D

DTC P1564 ASCD STEERING SWITCH
EC-517
< SERVICE INFORMATION >
C
D
E
F
G
H
I
J
K
L
MA
EC
N
P O
Without CONSULT-II
1. Turn ignition switch ON.
2. Check voltage between ECM terminal 99 and ground with press-
ing each button.
OK or NG
OK >> GO TO 8.
NG >> GO TO 3.
3.CHECK ASCD STEERING SWITCH GROUND CIRCUIT FOR OPEN AND SHORT
1. Turn ignition switch OFF.
2. Disconnect combination switch harness connector M102.
3. Disconnect ECM harness connector.
4. Check harness continuity between combination switch terminal
15 and ECM terminal 67.
Refer to Wiring Diagram.
5. Also check harness for short to ground and short to power.
OK or NG
OK >> GO TO 5.
NG >> GO TO 4.
4.DETECT MALFUNCTIONING PART
Check the following.
• Harness connectors M31, E152
• Harness connectors E5, F14
• Combination switch (spiral cable)
• Harness for open and short between ECM and combination switch
>> Repair open circuit or short to ground or short to power in harness or connectors.
5.CHECK ASCD STEERING SWITCH INPUT SIGNAL CIRCUIT FOR OPEN AND SHORT
1. Check harness continuity between ECM terminal 99 and combination switch terminal 14.
Refer to Wiring Diagram.
2. Also check harness for short to ground and short to power.
OK or NG
OK >> GO TO 7.
NG >> GO TO 6.
6.DETECT MALFUNCTIONING PART
Check the following.
• Harness connectors M31, E152
Switch Condition Voltage [V]
MAIN switchPressed Approx. 0
Released Approx. 4
CANCEL switchPressed Approx. 1
Released Approx. 4
RESUME/ACCELERATE
switchPressed Approx. 3
Released Approx. 4
SET/COAST switchPressed Approx. 2
Released Approx. 4
PBIB0311E
Continuity should exist.
BBIA0362E
Continuity should exist.

EC-518
< SERVICE INFORMATION >
DTC P1564 ASCD STEERING SWITCH
• Combination switch (spiral cable)
• Harness for open and short between ECM and combination switch
>> Repair open circuit or short to ground or short to power in harness or connectors.
7.CHECK ASCD STEERING SWITCH
Refer to EC-518, "
Component Inspection".
OK or NG
OK >> GO TO 8.
NG >> Replace ASCD steering switch. Refer to PS-13, "
Disassembly and Assembly".
8.CHECK INTERMITTENT INCIDENT
Refer to EC-138
.
>>INSPECTION END
Component InspectionINFOID:0000000003532052
ASCD STEERING SWITCH
1. Disconnect combination switch (spiral cable) harness connector M102.
2. Check continuity between combination switch (spiral cable) ter-
minals 14 and 15 with pushing each switch.
Switch Condition Resistance [Ω]
MAIN switchPressed Approx. 0
Released Approx. 4,000
CANCEL switchPressed Approx. 250
Released Approx. 4,000
RESUME/ACCELERATE
switchPressed Approx. 1,480
Released Approx. 4,000
SET/COAST switchPressed Approx. 660
Released Approx. 4,000
PBIB0967E