Infiniti M35/M45 Y50. Manual - part 691

DTC P1550 BATTERY CURRENT SENSOR

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DTC P1550 BATTERY CURRENT SENSOR

PFP:294G0

Component Description

NBS005LF

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

NBS005LG

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

NBS005LH

The MIL will not light up for this diagnosis.

NOTE:
If DTC P1550 is displayed with DTC P0643, first perform the trouble diagnosis for DTC P0643. Refer to

EC-1193, "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

P1550
1550

Battery current sensor circuit 
range/performance

The output voltage of the battery current 
sensor remains within the specified 
range while engine is running.

●

Harness or connectors
(The sensor circuit is open or shorted.)

●

Battery current sensor

EC-1238

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DTC P1550 BATTERY CURRENT SENSOR

DTC Confirmation Procedure

NBS005LI

If DTC Confirmation Procedure has been previously conducted, always turn ignition switch OFF and wait at
least 10 seconds before conducting the next test.
TESTING CONDITION:
Before performing the following procedure, confirm that battery voltage is more than 8V at idle.

 WITH CONSULT-II

1.

Turn ignition switch ON.

2.

Select “DATA MONITOR” mode with CONSULT-II.

3.

Start engine and wait at least 10 seconds.

4.

If 1st trip DTC is detected, go to 

EC-1240, "Diagnostic Proce-

dure"

 .

 WITH GST

Follow the procedure “WITH CONSULT-II” above.

SEF058Y

DTC P1550 BATTERY CURRENT SENSOR

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Wiring Diagram

NBS005LJ

TBWT1064E

EC-1240

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DTC P1550 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

NBS005LK

1. 

CHECK GROUND CONNECTIONS

1.

Turn ignition switch OFF.

2.

Loosen and retighten ground screws on the body. 
Refer to 

EC-864, "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
(Battery current sensor)

[Ignition switch: ON]

Approximately 5V

67

B/W

Sensor ground
(Battery current sensor)

[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