Nissan Frontier. Instruction — part 569

P1550 BATTERY CURRENT SENSOR

EC-847

< DTC/CIRCUIT DIAGNOSIS >

[VQ40DE FOR USA AND CANADA]

C

D

E

F

G

H

I

J

K

L

M

A

EC

N

P

O

P1550 BATTERY CURRENT SENSOR

Component Description

INFOID:0000000009481533

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 is installed to the battery cable at the negative terminal.

The sensor measures the charging/discharging current of the bat-

tery. 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

CHG-9, "System

Description"

.

CAUTION:

Never 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 battery dis-

charge may occur.

On Board Diagnosis Logic

INFOID:0000000009481534

The MIL will not illuminate for this diagnosis.

NOTE:

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

EC-830

.

DTC Confirmation Procedure

INFOID:0000000009481535

NOTE:

If DTC Confirmation Procedure has been previously conducted, always perform the following before conduct-

ing the next step.

1. Turn ignition switch OFF and wait at least 10 seconds.

2. Turn ignition switch ON.

3. Turn ignition switch OFF and wait at least 10 seconds.

TESTING CONDITION:

Before performing the following procedure, confirm that battery voltage is more than 8V at idle.
1. Start engine and wait at least 10 seconds.
2. Check 1st trip DTC.
3. If 1st trip DTC is detected, go to

EC-847, "Diagnosis Procedure"

.

Diagnosis Procedure

INFOID:0000000009481536

1.

CHECK GROUND CONNECTIONS

1. Turn ignition switch OFF.

2. Loosen and retighten three ground screws on the body.

Refer to

EC-617, "Ground Inspection"

.

OK or NG

OK

>> GO TO 2.

NG

>> Repair or replace ground connections.

2.

CHECK BATTERY CURRENT SENSOR POWER SUPPLY CIRCUIT

BBIA0582E

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-848

< DTC/CIRCUIT DIAGNOSIS >

[VQ40DE FOR USA AND CANADA]

P1550 BATTERY CURRENT SENSOR

1. Disconnect battery current sensor harness connector.

2. Turn ignition switch ON.

3. Check voltage between battery current sensor terminal 1 and ground with CONSULT or tester.

OK or NG

OK

>> GO TO 4.

NG

>> GO TO 3.

3.

DETECT MALFUNCTIONING PART

Check the following.

• Harness connectors E5, F14

• 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.

4.

CHECK BATTERY CURRENT SENSOR GROUND CIRCUIT FOR OPEN AND SHORT

1. Turn ignition switch OFF.

2. Disconnect ECM harness connector.

3. Check harness continuity between battery current sensor terminal 2 and ECM terminal 68.

4. Also check harness for short to ground and short to power.
OK or NG

OK

>> GO TO 6.

NG

>> GO TO 5.

5.

DETECT MALFUNCTIONING PART

Check the following.

• Harness connectors E5, F14

• 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.

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 66.

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.

• Harness connectors E5, F14

BBIA0582E

Voltage: Approximately 5V

Continuity should exist.

Continuity should exist.

P1550 BATTERY CURRENT SENSOR

EC-849

< DTC/CIRCUIT DIAGNOSIS >

[VQ40DE FOR USA AND CANADA]

C

D

E

F

G

H

I

J

K

L

M

A

EC

N

P

O

• 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-849, "Component Inspection"

.

OK or NG

OK

>> GO TO 9.

NG

>> Replace battery negative cable assembly.

9.

CHECK INTERMITTENT INCIDENT

Refer to

GI-42, "Intermittent Incident"

.

>> INSPECTION END

Component Inspection

INFOID:0000000009481537

BATTERY CURRENT SENSOR

1. Reconnect harness connectors disconnected.
2. Disconnect battery negative cable.
3. Install jumper cable between battery negative terminal and body

ground.

4. Turn ignition switch ON.

5. Check voltage between ECM terminal 66 (battery current sensor signal) and ground.

6. If NG, replace battery negative cable assembly.

BBIA0588E

Voltage: Approximately 2.5V

EC-850

< DTC/CIRCUIT DIAGNOSIS >

[VQ40DE FOR USA AND CANADA]

P1551, P1552 BATTERY CURRENT SENSOR

P1551, P1552 BATTERY CURRENT SENSOR

Component Description

INFOID:0000000009481538

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 is installed to the battery cable at the negative terminal.

The sensor measures the charging/discharging current of the bat-

tery. 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

CHG-9, "System

Description"

.

CAUTION:

Never 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.

On Board Diagnosis Logic

INFOID:0000000009481539

The MIL will not illuminate 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-830

.

DTC Confirmation Procedure

INFOID:0000000009481540

NOTE:

If DTC Confirmation Procedure has been previously conducted, always perform the following before conduct-

ing the next step.

1. Turn ignition switch OFF and wait at least 10 seconds.

2. Turn ignition switch ON.

3. Turn ignition switch OFF and wait at least 10 seconds.

TESTING CONDITION:

Before performing the following procedure, confirm that battery voltage is more than 8V with ignition

switch ON
1. Turn ignition switch ON and wait at least 10 seconds.
2. Check 1st trip DTC.
3. If 1st trip DTC is detected, go to

EC-850, "Diagnosis Procedure"

.

Diagnosis Procedure

INFOID:0000000009481541

1.

CHECK GROUND CONNECTIONS

1. Turn ignition switch OFF.

2. Loosen and retighten three ground screws on the body.

Refer to

EC-617, "Ground Inspection"

.

OK or NG

OK

>> GO TO 2.

NG

>> Repair or replace ground connections.

BBIA0582E

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.

• 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 sen-
sor is sent to ECM.