Infiniti M35/M45 Y50. Manual - part 518

DTC P1554 BATTERY CURRENT SENSOR

EC-545

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DTC P1554 BATTERY CURRENT SENSOR

PFP:294G0

Component Description

NBS0054C

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 Mode

NBS0054D

Specification data are reference values.

*: Before measuring the terminal voltage, confirm that the battery is fully charged. Refer to 

SC-5, "SPECIFIC GRAVITY CHECK"

 .

On Board Diagnosis Logic

NBS0054E

The MIL will not light up for this diagnosis.

NOTE:
If DTC P1554 is displayed with DTC P0643, first perform the trouble diagnosis for DTC P0643. Refer to

EC-486, "DTC P0643 SENSOR POWER SUPPLY"

 .

PBIB2685E

MONITOR ITEM

CONDITION

SPECIFICATION

BAT CUR SEN

●

Engine speed: Idle

●

Battery: Fully charged*

●

Selector lever: P or N

●

Air conditioner switch: OFF

●

No load

Approx. 2,600 - 3,500mV

DTC No.

Trouble diagnosis name

DTC detecting condition

Possible cause

P1554
1554

Battery current sensor perfor-
mance

The 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-546

[VQ35DE]

DTC P1554 BATTERY CURRENT SENSOR

Overall Function Check

NBS0054F

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.

2.

Select “BAT CUR SEN” in “DATA MONITOR” mode with CON-
SULT-II.

3.

Check “BAT CUR SEN” indication for 10 seconds.
“BAT CUR SEN” should be above 2,300mV at least once.

4.

If NG, go to 

EC-548, "Diagnostic Procedure"

 .

 WITH GST

1.

Start engine and let it idle.

2.

Check voltage between ECM terminal 71 (battery current sensor
signal) and ground for 10 seconds.
The voltage should be above 2.3V at least once.

3.

If NG, go to 

EC-548, "Diagnostic Procedure"

 .

PBIB2615E

PBIB2616E

DTC P1554 BATTERY CURRENT SENSOR

EC-547

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Wiring Diagram

NBS0054G

TBWT0995E

EC-548

[VQ35DE]

DTC P1554 BATTERY CURRENT SENSOR

Specification data are reference values and are measured between each terminal and ground.

CAUTION:

Do not use ECM ground terminals when measuring input/output voltage. Doing so may result in dam-
age to the ECM's transistor. Use a ground other than ECM terminals, such as the ground.

*: Before measuring the terminal voltage, confirm that the battery is fully charged. Refer to 

SC-5, "SPECIFIC GRAVITY CHECK"

 .

Diagnostic Procedure

NBS0054H

1. 

CHECK GROUND CONNECTIONS

1.

Turn ignition switch OFF.

2.

Loosen and retighten two ground screws on the body. 
Refer to 

EC-160, "Ground Inspection"

 .

OK or NG

OK

>> GO TO 2.

NG

>> Repair or replace ground connections.

TER-

MINAL 

NO.

WIRE 

COLOR

ITEM

CONDITION

DATA (DC Voltage)

49

B/Y

Sensor power supply
(Refrigerant pressure sen-
sor, Battery current sensor)

[Ignition switch: ON]

Approximately 5V

67

B/W

Sensor ground

[Engine is running]

●

Warm-up condition

●

Idle speed

Approximately 0V

71

L/R

Battery current sensor

[Engine is running]

●

Battery: Fully charged*

●

Idle speed

Approximately 2.6 - 3.5V

1.

Body ground M70

2.

Body ground M16

PBIB2782E