Nissan Altima HL32 Hybrid. Manual - part 550

P0A9C-123

HBB-57

< COMPONENT DIAGNOSIS >

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E

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HBB

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P0A9C-123

Description

INFOID:0000000004212270

The battery temperature sensors are provided at 4 locations on the bottom of the HV battery. The resistance of

the thermistor, which is built into each battery temperature sensor, varies in accordance with changes in the

HV battery temperature. The lower the battery temperature, the higher the thermistor resistance. Conversely,

the higher the temperature, the lower the resistance. The battery smart unit uses the battery temperature sen-

sors to detect the HV battery temperature, and sends the detected values to the hybrid vehicle control ECU.

Based on these results, the hybrid vehicle control ECU controls the blower fan. (The blower fan starts when

the HV battery temperature rises above a predetermined level.)

DTC Logic

INFOID:0000000004212271

DTC DETECTION LOGIC

If the temperature indicated by the battery temperature sensor is lower than the standard level (open), or is

higher than the standard level (short), the battery smart unit interprets this as a sensor malfunction. If the bat-

JMCIA0089GB

JMCIA0110GB

HBB-58

< COMPONENT DIAGNOSIS >

P0A9C-123

tery smart unit detects that the HV battery temperature is out of its normal range or its value is abnormal, the

hybrid vehicle control ECU will illuminate the MIL and set a DTC.

Diagnosis Procedure

INFOID:0000000004212272

1.

PRECONDITIONING

• Before inspecting the high-voltage system, 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-volt-

age 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 FOR DTC (DTC P0A1F-123 IS OUTPUT)

1. Turn ignition switch ON.

2. Check DTC.
Is DTC P0A1F-123 detected?

YES

>> Go to Diagnosis Procedure relevant to output DTC.

NO

>> GO TO 3.

3.

CHECK BATTERY TEMPERATURE SENSOR (BATTERY TEMPERATURE SENSOR 0 TO 3)

CAUTION:

Be sure to wear insulated gloves.

1. Turn ignition switch OFF.

2. Remove the HV battery assembly. (Refer to 

HBB-97, "Removal and Installation"

).

3. Visually check the installation of the battery temperature sensors (0 to 3) through the exhaust duct instal-

lation hole.

DTC No.

INF code

Trouble diagnosis name

DTC detecting condition

Possible cause

P0A9C

123

Hybrid battery temperature 
sensor “A”

When the battery temperature sensor 
performance is abnormal (1 trip detec-
tion/2 trip detection)

• HV battery (Battery temperature 

sensor)

• Battery smart unit

1.

HV battery module

2.

Battery temperature sensor

3.

Exhaust duct (installation slot)

4-A. Battery temperature sensor 3

4-B. Battery temperature sensor 2

4-C. Battery temperature sensor 1

4-D. Battery temperature sensor 0

ALCIA0006ZZ

P0A9C-123

HBB-59

< COMPONENT DIAGNOSIS >

D

E

F

G

H

I

J

K

L

M

A

B

HBB

N

O

P

NOTE:

Do not poke the battery temperature sensors with a stick or other objects when checking. Doing so may

damage the sensors.

OK or NG

OK

>> Replace battery smart unit. (Refer to 

HBB-101, "Removal and Installation"

).

NG

>> Replace HV battery. (Refer to 

HBB-97, "Removal and Installation"

).

The battery temperature sensors (0 to 3) are securely installed.

HBB-60

< COMPONENT DIAGNOSIS >

P0A9D-123, P0A9E-123

P0A9D-123, P0A9E-123

Description

INFOID:0000000004212273

The battery temperature sensors are provided at 4 locations on the bottom of the HV battery. The resistance of

the thermistor, which is built into each battery temperature sensor, varies in accordance with changes in the

HV battery temperature. The lower the battery temperature, the higher the thermistor resistance. Conversely,

the higher the temperature, the lower the resistance. The battery smart unit uses the battery temperature sen-

sors to detect the HV battery temperature, and sends the detected values to the hybrid vehicle control ECU.

Based on these results, the hybrid vehicle control ECU controls the blower fan. (The blower fan starts when

the HV battery temperature rises above a predetermined level.)

DTC Logic

INFOID:0000000004212274

DTC DETECTION LOGIC

If the temperature indicated by the battery temperature sensor is lower than the standard level (open), or is

higher than the standard level (short), the battery smart unit interprets this as a sensor malfunction. If the bat-

JMCIA0089GB

JMCIA0110GB