Nissan Altima HL32 Hybrid. Manual - part 671

P0AA7-727

HBC-433

< COMPONENT DIAGNOSIS >

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P0AA7-727

Description

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The hybrid vehicle control ECU monitors the insulation monitoring circuit located in the battery smart unit and

detects a malfunction.

DTC Logic

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DTC DETECTION LOGIC

Diagnosis Procedure

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1.

PRECONDITIONING

• Before inspecting the high-voltage system or disconnecting the low voltage connector of the inverter with

converter assembly, take safety precautions such as wearing insulated gloves and removing the service

plug grip to prevent electrical shocks. After removing the service plug grip, put it in your pocket to prevent

other technicians from accidentally reconnecting it while you are working on the high-voltage system.

• After disconnecting the service plug grip, wait for at least 10 minutes before touching any of the high-voltage

connectors or terminals.

• Waiting for at least 10 minutes is required to discharge the high-voltage capacitor inside the inverter with

converter assembly.

>> GO TO 2.

2.

REPLACE BATTERY SMART UNIT

Refer to 

HBB-101, "Removal and Installation"

.

>> COMPLETED

DTC No.

INF code

Trouble diagnosis name

DTC detecting condition

Possible cause

P0AA7

727

Hybrid Battery Voltage Isolation 
Sensor Circuit

Malfunction in the insulation 
monitoring circuit located in the 
battery smart unit

Battery smart unit

HBC-434

< COMPONENT DIAGNOSIS >

P0AC0-817

P0AC0-817

Description

INFOID:0000000004212056

The battery current sensor, which is located in the HV battery junction block on the positive side of the HV bat-

tery, detects the amperage that flows to and from the HV battery. The battery smart unit receives a voltage of

between 0 and 5 V that is in proportion to the amperage flowing in the cable. This voltage goes into the IB ter-

minal from the battery current sensor. A battery current sensor output voltage below 2.5 V indicates that the

HV battery is being charged, and a voltage above 2.5 V indicates that the HV battery is being discharged. The

hybrid vehicle control ECU determines the amount of either charge or discharge amperage that is being

received by the HV battery assembly based on the signals that are input to terminal IB of the battery smart unit

from the battery current sensor. The hybrid vehicle control ECU also calculates the SOC (state of charge) of

the HV battery based on the accumulated amperage.

DTC Logic

INFOID:0000000004212057

DTC DETECTION LOGIC

Diagnosis Procedure

INFOID:0000000004212058

1.

PRECONDITIONING

• Before inspecting the high-voltage system or disconnecting the low voltage connector of the inverter with

converter assembly, take safety precautions such as wearing insulated gloves and removing the service

plug grip to prevent electrical shocks. After removing the service plug grip, put it in your pocket to prevent

other technicians from accidentally reconnecting it while you are working on the high-voltage system.

• After disconnecting the service plug grip, wait for at least 10 minutes before touching any of the high-voltage

connectors or terminals.

• Waiting for at least 10 minutes is required to discharge the high-voltage capacitor inside the inverter with

converter assembly.

>> GO TO 2.

2.

CHECK DTC OUTPUT (HYBRID SYSTEM)

1. Turn ignition switch ON.

2. Check DTC.

JMCIA0090GB

DTC No. INF code

Trouble diagnosis name

DTC detecting condition

Possible cause

P0AC0

817

Hybrid battery pack current sensor 
circuit range/performance

HV battery current sensor performance 
problem

• HV relay assembly
• Battery smart unit

P0AC0-817

HBC-435

< COMPONENT DIAGNOSIS >

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A or B

A

>> GO TO 3.

B

>> Go to Diagnosis Procedure relevant to output DTC.

3.

REPLACE HV RELAY ASSEMBLY

Refer to 

HBB-105, "Removal and Installation"

.

>> GO TO 4.

4.

CLEAR DTC

1. Turn ignition switch ON.

2. Read and record the DTCs and freeze frame data.

3. Clear DTC.

>> GO TO 5.

5.

SIMULATION TEST

1. Turn ignition switch ON (READY).

2. Drive the  vehicle under the similar conditions to freeze frame data.

>> GO TO 6.

6.

CHECK DTC OUTPUT (HYBRID SYSTEM)

1. Stop vehicle.

2. Check DTC again.

A or B

A

>> INSPECTION END

B

>> Replace battery smart unit (See 

HBB-101, "Removal and Installation"

).

Result

Proceed to

P0AC0-817 only is output.

A

P0A1F-123 is also output.

B

Result

Proceed to

P0AC0-817 is not output.

A

P0AC0-817 is output again.

B

HBC-436

< COMPONENT DIAGNOSIS >

P0ADB-227, P0ADC-226

P0ADB-227, P0ADC-226

Description

INFOID:0000000004212059

The SMRs (System Main Relay) are the relays that connect or disconnect the high voltage power system in

accordance with commands from the hybrid vehicle control ECU.

The SMR system is composed of three SMRs and one system main resistor. SMRB and SMRG are located on

the HV relay assembly in the battery carrier under the HV battery. SMRP and the system main resistor are

located in the hybrid vehicle converter (DC/DC converter) assembly in the battery carrier.

To connect to the high voltage power system, the vehicle will first turn on SMRP and SMRB to charge the vehi-

cle through the system main resistor. Then, SMRP will be turned off after the SMRG is turned on. To shut off

the high voltage power system, SMRB and SMRG are turned off.

When there is an open in the AMD line or IGCT line, the following DTCs are output:

P0AE6-225 is output first because the time required for diagnosis is the shortest.

Trouble area

Malfunction

DTC

Occurrence condition

Open in AMD line

DC/DC converter malfunction

P0A08-264

May not occur

Open in VLO, short to GND

P0A09-591

May not occur

IDH frequency error

P2519-766

Occurs

Open in SMRP, short to GND

P0AE6-225

Occurs

Open in IGCT line

Open in NODD, short to GND

P0A09-265

Occurs

Open in VLO, short to GND

P0A09-591

Occurs

IDH frequency error

P2519-766

Occurs

Open in SMRP, short to GND

P0AE6-225

Occurs