Infiniti M35/M45 Y50. Manual - part 514

DTC P1550 BATTERY CURRENT SENSOR

EC-529

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6. 

CHECK BATTERY CURRENT SENSOR INPUT SIGNAL CIRCUIT FOR OPEN AND SHORT

1.

Check harness continuity between battery current sensor terminal 3 and ECM terminal 71.
Refer to Wiring Diagram.

2.

Also check harness for short to ground and short to power.

OK or NG

OK

>> GO TO 8.

NG

>> GO TO 7.

7. 

DETECT MALFUNCTIONING PART

Check the following.

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Harness connectors E10, F1

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Harness for open or short between battery current sensor and ECM

>> Repair open circuit or short to ground or short to power in harness or connectors.

8. 

CHECK BATTERY CURRENT SENSOR

Refer to 

EC-529, "Component Inspection"

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OK or NG

OK

>> GO TO 9.

NG

>> Replace battery negative cable assembly.

9. 

CHECK INTERMITTENT INCIDENT

Refer to 

EC-153, "TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT"

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>> INSPECTION END

Component Inspection

NBS0053X

BATTERY CURRENT SENSOR

1.

Reconnect harness connectors disconnected.

2.

Disconnect battery negative cable (1).

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: To body ground

3.

Install jumper cable (A) between battery negative terminal and
body ground.

4.

Turn ignition switch ON.

Continuity should exist.

PBIB2724E

EC-530

[VQ35DE]

DTC P1550 BATTERY CURRENT SENSOR

5.

Check voltage between ECM terminal 71 (battery current sensor
signal) and ground.

6.

If NG, replace battery negative cable assembly.

Voltage: Approximately 2.5V

PBIB2617E

DTC P1551, P1552 BATTERY CURRENT SENSOR

EC-531

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DTC P1551, P1552 BATTERY CURRENT SENSOR

PFP:294G0

Component Description

NBS0053Y

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

NBS0053Z

Specification data are reference values.

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

SC-5, "SPECIFIC GRAVITY CHECK"

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On Board Diagnosis Logic

NBS00540

The MIL will not light up for this diagnosis.

NOTE:
If DTC P1551 or P1552 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

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Engine speed: Idle

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Battery: Fully charged*

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Selector lever: P or N

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Air conditioner switch: OFF

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No load

Approx. 2,600 - 3,500mV

DTC No.

Trouble diagnosis name

DTC detecting condition

Possible cause

P1551
1551

Battery current sensor circuit 
low input

An excessively low voltage from the sen-
sor is sent to ECM.

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

●

Battery current sensor

P1552
1552

Battery current sensor circuit 
high input

An excessively high voltage from the 
sensor is sent to ECM.

EC-532

[VQ35DE]

DTC P1551, P1552 BATTERY CURRENT SENSOR

DTC Confirmation Procedure

NBS00541

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 with ignition
switch ON

 WITH CONSULT-II

1.

Turn ignition switch ON.

2.

Select “DATA MONITOR” mode with CONSULT-II.

3.

Wait at least 10 seconds.

4.

If 1st trip DTC is detected, go to 

EC-534, "Diagnostic Procedure"

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 WITH GST

Follow the procedure “WITH CONSULT-II” above.

SEF058Y