Nissan Altima HL32 Hybrid. Manual - part 1058

DIAGNOSIS SYSTEM (EPS CONTROL UNIT)

STC-11

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CAUTION:

If “LOST COMM (BRAKE) [U0129]” or “LOST COMM (HV ECU) [U0293]” is displayed with other DTCs, first perform the trouble
diagnosis for CAN communication line.
NOTE:
“TORQUE SENSOR [C1604]”, “EPS MOTOR [C1606]”, “EEPROM [C1607]” and “CONTROL UNIT [C1608]” may be detected also for
malfunctions other than EPS system components.

DATA MONITOR MODE

Display Item List

C16A1

EPS DCDC CONVERTER

Malfunction has been detected from EPS DC/DC 
converter.

• EPS DC/DC converter
• HV ECU
• Harness or connector
• EPS control unit

C16A2

ANG SE INT NOT PFM

EPS motor angle sensor initialization is not per-
formed.

• EPS motor angle sensor ini-

tialization not performed

U0129

LOST COMM (BRAKE)

CAN communication line* data communication error 
is detected.
(An error signal is detected from brake ECU.)

• Harness or connector

(CAN communication line)

• Brake ECU (When U0129 

only is output)

U0293

LOST COMM (HV ECU)

CAN communication line* data communication error 
is detected.
(An error signal is detected from HV ECU.)

• Harness or connector

(CAN communication line)

• HV ECU (When U0293 only 

is output)

DTC

Item

(CONSULT-III screen term)

DTC detecting condition

Possible cause

Monitor item (Unit)

Remarks

VEHICLE SPEED [km/h]

Vehicle speed is displayed. 

MTR Q CRNT [A]

Current value consumed by EPS motor (Q shaft) is displayed.

MTR CRNT CMND [A]

Current commanded value to EPS motor is displayed.

STR ANGL SPD [deg/s]

Steering angle speed is displayed.

THERM TEMP [degC]

EPS control unit internal temperature is displayed.

IGN VOLT [V]

EPS control unit ignition power supply voltage is displayed.

STR ANGL SIG [0/1/2/3]

Steering angle sensor signal is displayed.

TRQ SEN1 ANG [deg]

Torque sensor 1 rotation angle is displayed.

TRQ SEN2 ANG [deg]

Torque sensor 2 rotation angle is displayed.

TRQ1 ZERO VAL [deg]

Torque sensor 1 rotation angle at zero point is displayed.

TRQ2 ZERO VAL [deg]

Torque sensor 2 rotation angle at zero point is displayed.

STR TORQUE [Nm]

Steering wheel turning force detected by torque sensor is displayed.

MTR ROTA ANG [deg]

EPS motor rotation angle is displayed.

MTR D CRNT [A]

Current value consumed by EPS motor (D shaft) is displayed.

MOTOR VOLT [V]

Power supply voltage for EPS motor is displayed

MTR U VOLT [V]

EPS motor U terminal output voltage is displayed.

MTR V VOLT [V]

EPS motor V terminal output voltage is displayed.

MTR W VOLT [V]

EPS motor W terminal output voltage is displayed.

IG ON/OFF FRQ

Ignition OFF frequency after system malfunction is displayed.

PRTCT OVRLD

Protect overload status is displayed.

MTR PWR LOW

Memory of decrease of power supply voltage of EPS motor is displayed.

ST ANG SIG IN

Steering angle sensor signal interruption is displayed.

VHCL SPD INTR

Vehicle speed signal interruption is displayed.

BATTERY VOLT [V]

EPS control unit battery power supply voltage is displayed.

STC-12

< FUNCTION DIAGNOSIS >

DIAGNOSIS SYSTEM (EPS CONTROL UNIT)

DRDD VOLT [V]

EPS DC/DC converter power supply voltage is displayed.

HV BATT VOLT [V]

HV battery power supply voltage is displayed.

PS ASIST PRMS

Power steering assist permission status is displayed.

PS AST STP RQ

Power steering assist stop request signal is displayed.

EPS CNVRT SIG

EPS DC/DC converter status is displayed.

PS ASSIST SIG

Power steering assist status is displayed.

READY STATE

READY status is displayed.

ANG SEN INITL [ON/OFF]

EPS motor angle sensor initialization status is displayed.

TRQ SEN CLBRT [ON/OFF]

Torque sensor calibration status is displayed.

OFF ELEC ANG1 [deg]

Offset electrical angle 1 (column side) is displayed.

OFF ELEC ANG2 [deg]

Offset electrical angle 2 (pinion side) is displayed.

TRQ PNT AMNT [Nm]

Amount of zero torque point compensation is displayed.

OFF ELEC ANG3 [deg]

Offset electrical angle 3 (motor side) is displayed.

DTC

The number of DTCs currently and previously stored is displayed.

Monitor item (Unit)

Remarks

C1601 BATTERY POWER SUPPLY

STC-13

< COMPONENT DIAGNOSIS >

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COMPONENT DIAGNOSIS

C1601 BATTERY POWER SUPPLY

Description

INFOID:0000000004212827

EPS control unit receives power from the battery and then provides power to the EPS DC/DC converter and

EPS motor control circuit. (Or EPS control unit receives power for EPS DC/DC converter and EPS motor con-

trol circuit from the battery.)

DTC Logic

INFOID:0000000004212828

DTC DETECTION LOGIC

DTC CONFIRMATION PROCEDURE

1.

ERASE DTC MEMORY

 With CONSULT-III

1. Record DTC.

2. Erase DTC once.

NOTE:

After erasing DTC record, currently occurred DTC can be detected by reading out DTC again.

>> GO TO 2.

2.

PERFORM DTC CONFIRMATION

 With CONSULT-III

1. Turn the ignition switch ON (READY).

2. Steer 360

° leftward and rightward slowly.

3. Return the steering wheel to the straight-ahead position.

4. Perform the self-diagnosis.
Is DTC “C1601” detected?

YES

>> Proceed to 

STC-13, "Diagnosis Procedure"

.

NO

>> INSPECTION END

Diagnosis Procedure

INFOID:0000000004212829

1.

CHECK EPS CONTROL UNIT POWER SUPPLY CIRCUIT

1. Turn the ignition switch OFF.

2. Disconnect EPS control unit harness connector.

3. Check the voltage between EPS control unit harness connector

and ground.

Is the inspection result normal?

YES

>> GO TO 2.

NO

>> • Check the following. If any items are damaged, repair

or replace damaged parts.

- 10A fuse (#63)

DTC

Item

(CONSULT-III screen term)

DTC detecting condition

Possible cause

C1601

BATTERY VOLT

When the power supply malfunction supplied to EPS 
control unit is detected.

• Power supply
• Harness or connector
• EPS control unit

EPS control unit

Ground

Voltage (Approx.)

Connector

Terminal

E302

4

Ground

Battery voltage

PGIA0085E

STC-14

< COMPONENT DIAGNOSIS >

C1601 BATTERY POWER SUPPLY

- Harness for short or open between battery and EPS control unit harness connector

2.

CHECK EPS CONTROL UNIT GROUND CIRCUIT

1. Turn the ignition switch OFF.

2. Disconnect EPS control unit harness connector.

3. Check the continuity between EPS control unit harness connec-

tor and ground.

Also check harness for short to ground and short to power.

Is the inspection result normal?

YES

>> Replace EPS control unit. Refer to 

STC-58, "Removal

and Installation"

.

NO

>> Repair open circuit or short to ground or short to power in harness or connectors.

Special Repair Requirement

INFOID:0000000004212830

1.

INITIALIZE EPS MOTOR ANGLE SENSOR AND CALIBRATE TORQUE SENSOR AGAIN

Always perform EPS motor angle sensor initialization and torque sensor calibration after replacing EPS con-

trol unit or steering gear assembly. Refer to 

STC-5, "EPS MOTOR ANGLE SENSOR INITIALIZATION AND

TORQUE SENSOR CALIBRATION : Special Repair Requirement"

.

>> END

EPS control unit

Ground

Continuity

Connector

Terminal

E302

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Ground

Existed

PGIA0086E