Nissan Altima HL32 Hybrid. Manual - part 635

P0A78-523

HBC-289

< COMPONENT DIAGNOSIS >

D

E

F

G

H

I

J

K

L

M

A

B

HBC

N

O

P

Turning ignition switch off causes the voltage in the inverter to discharge. The inverter voltage is almost 0 V

after discharge. The DTC will be stored if the inverter voltage is more than the specified value after discharge.

Diagnosis Procedure

INFOID:0000000004211947

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

1. Turn ignition switch ON.

2. Check DTC.

Is DTC detected?

YES

>> Go to Diagnosis Procedure relevant to output DTC.

NO

>> Replace inverter with converter assembly (See 

HBC-638, "Removal and Installation"

).

JMCIA0100GB

DTC No.

Relevant Diagnosis

P0AE2-773, 161

SMRP

P0AE0-228

SMRG

P0ADC-226

SMRB

P0A1A-156, 658, 659, 151, 155, P0A1B-511, 164, 
163, 512, 193, 786, 788, 661, P0A78-266, 267, 
P0A94-442

VH sensor circuit

P0A1A-200, 791, 792, 793, P0A1B-192, 168, 794, 
795, 796, P0A3F-243, P0A41-245, P0A40-500, 
P0A4B-253, P0A4C-513, P0A4D-255

MG resolver circuit

HBC-290

< COMPONENT DIAGNOSIS >

P0A78-586

P0A78-586

Description

INFOID:0000000004211948

The inverter converts high-voltage direct current from the HV battery and alternating current for MG2 and

MG1. The inverter contains a three-phase bridge circuit, which consists of six power transistors each for MG2

and MG1, that converts direct current to three-phase alternating current. The MG ECU controls the actuation

of the power transistors. The inverter transmits information that is necessary for effecting control, such as the

amperage and voltage, to the MG ECU.

The MG ECU uses a voltage sensor, which is built into the inverter, to detect boosted high voltage to allow

control of the voltage boost.

The inverter voltage sensor outputs voltage that varies between 0 and 5 V in accordance with the changes in

the high voltage. The higher the high voltage, the higher the output voltage, and the lower the high voltage, the

lower the output voltage.

P0A78-586

HBC-291

< COMPONENT DIAGNOSIS >

D

E

F

G

H

I

J

K

L

M

A

B

HBC

N

O

P

The MG ECU monitors the inverter voltage and detects malfunctions.

DTC Logic

INFOID:0000000004211949

DTC DETECTION LOGIC

The hybrid vehicle control ECU monitors the inverter voltage (VH) sensor signal. If the hybrid vehicle control

ECU detects a fault in the sensor signal, the hybrid vehicle control ECU interprets this as a VH sensor failure.

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

JMCIA0099GB

DTC No.

INF code

Trouble diagnosis name

DTC detecting condition

Possible cause

P0A78

586

Drive Motor “A” Inverter Performance

Inverter voltage (VH) sensor 
performance problem

Inverter with converter assembly

HBC-292

< COMPONENT DIAGNOSIS >

P0A78-586

Diagnosis Procedure

INFOID:0000000004211950

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.
Is DTC detected?

YES

>> Go to Diagnosis Procedure relevant to output DTC.

NO

>> Replace inverter with converter assembly (See 

HBC-638, "Removal and Installation"

).