Nissan Leaf. Manual - part 1193

P0A44 DRIVE MOTOR A OVER SPEED

TMS-53

< DTC/CIRCUIT DIAGNOSIS >

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P0A44 DRIVE MOTOR A OVER SPEED

DTC Logic

INFOID:0000000010120937

DTC DETECTION LOGIC

DTC CONFIRMATION PROCEDURE

CAUTION:

Always drive vehicle at a safe speed.

1.

PRECONDITIONING

If “DTC CONFIRMATION PROCEDURE” has been previously conducted, always power switch OFF and wait

at least 10 seconds before conducting the next test.

>> GO TO 2.

2.

CHECK DTC DETECTION

With CONSULT

1. Set the vehicle to READY and wait for 10 seconds or more.

2. Accelerate to 60 km/h (37 MPH).

3. Stop the vehicle.

4. Check DTC.
Is “P0A44” detected?

YES

>> Go to 

TMS-53, "Diagnosis Procedure"

.

NO-1 >> To check malfunction symptom before repair: Refer to 

GI-53, "Intermittent Incident"

.

NO-2 >> Confirmation after repair: INSPECTION END

Diagnosis Procedure

INFOID:0000000010120938

1.

CHECK TRACTION MOTOR INVERTER HARNESS CONNECTOR

1. Power switch OFF.

2. Check the connection conditions of the traction motor inverter harness connector.
Is the inspection result normal?

YES

>> GO TO 2.

NO

>> Repair or replace damaged parts.

2.

CHECK TRACTION MOTOR HARNESS CONNECTOR

Check the connection conditions of the traction motor harness connector.
Is the inspection result normal?

YES

>> GO TO 3.

NO

>> Repair or replace damaged parts.

3.

CHECK TRACTION MOTOR RESOLVER CIRCUIT

1. Disconnect the traction motor inverter harness connector.

2. Check the resistance between traction motor inverter vehicle side harness connector terminals and

ground.

DTC

CONSULT screen terms

(Trouble diagnosis content)

Malfunction detected condition

Possible causes

P0A44

DRIVE MOTOR A OVER SPEED
(Drive Motor “A” Position Sensor 
Circuit Overspeed)

If the value detected for motor speed at 
the traction motor resolver is too high

• Harness or connectors

(Each circuit is open or shorted.)

• Traction  motor
• Traction motor inverter

TMS-54

< DTC/CIRCUIT DIAGNOSIS >

P0A44 DRIVE MOTOR A OVER SPEED

Is the inspection result normal?

YES

>> GO TO 4.

NO

>> Repair or replace damaged parts.

4.

 CHECK TRACTION MOTOR RESOLVER CIRCUIT

1. Disconnect the traction motor harness connector.

2. Check the resistance between traction motor inverter vehicle side harness connector terminals and trac-

tion motor vehicle side harness connector terminals.

3. Check the harness for short.

Is the inspection result normal?

YES

>> GO TO 5.

NO

>> Repair or replace damaged parts.

5.

CHECK TRACTION MOTOR RESOLVER

Check the traction motor resolver. Refer to 

TMS-54, "Component Inspection (Traction Motor Resolver)"

.

Is the inspection result normal?

YES

>> Replace the traction motor inverter. Refer to 

TMS-103, "Removal and Installation"

.

NO

>> Replace the traction motor. Refer to 

TMS-109, "Removal and Installation"

.

Component Inspection (Traction Motor Resolver)

INFOID:0000000010120939

1.

CHECK TRACTION MOTOR RESOLVER

1. Disconnect the traction motor connector.

2. Check the resistance between traction motor connector terminals.

Traction motor inverter

Ground

Resistance

Connector

Terminal

F13

17

Ground

100 k

Ω or more

18

19

20

21

27

Traction motor inverter

Traction motor

Resistance

Connector

Terminal

Connector

Terminal

F13

17

F14

6

1 

Ω or less

18

7

19

5

20

1

21

8

27

2

Traction motor inverter

Resistance

Connector

Terminal

F13

17

18

100 k

Ω or more

20

21

19

27

P0A44 DRIVE MOTOR A OVER SPEED

TMS-55

< DTC/CIRCUIT DIAGNOSIS >

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Is the inspection result normal?

YES

>> INSPECTION END

NO

>> Replace the traction motor due to malfunction in the traction motor resolver. Refer to 

TMS-109,

"Removal and Installation"

.

Traction motor connector

Resistance

Terminal

1

8

20 – 35 

Ω

2

5

8 – 15 

Ω

6

7

20 – 35 

Ω

TMS-56

< DTC/CIRCUIT DIAGNOSIS >

P0A78 DRIVE MOTOR A INVERTER

P0A78 DRIVE MOTOR A INVERTER

DTC Logic

INFOID:0000000010120940

DTC DETECTION LOGIC

DTC CONFIRMATION PROCEDURE

1.

PRECONDITIONING

If “DTC CONFIRMATION PROCEDURE” has been previously conducted, always power switch OFF and wait

at least 10 seconds before conducting the next test.

>> GO TO 2.

2.

CHECK DTC DETECTION

With CONSULT

1. Power switch ON and wait for 10 seconds or more.

2. Check DTC.
Is “P0A78” detected?

YES

>> Go to 

TMS-56, "Diagnosis Procedure"

.

NO-1 >> To check malfunction symptom before repair: Refer to 

GI-53, "Intermittent Incident"

.

NO-2 >> Confirmation after repair: INSPECTION END

Diagnosis Procedure

INFOID:0000000010120941

1.

REPLACE TRACTION MOTOR INVERTER

Replace the traction motor inverter. Refer to 

TMS-103, "Removal and Installation"

.

>> END

DTC

CONSULT screen terms

(Trouble diagnosis content)

Malfunction detected condition

Possible cause

P0A78

DRIVE MOTOR A INVERTER
(Drive Motor “A” Inverter Perfor-
mance)

A malfunction is detected in the 
traction motor inverter (motor con-
troller)

Traction motor inverter