Nissan Sentra. Manual - part 828

DIAGNOSIS AND REPAIR WORKFLOW

STC-19

< BASIC INSPECTION >

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BASIC INSPECTION

DIAGNOSIS AND REPAIR WORKFLOW

Work Flow

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DETAILED FLOW

1.

INTERVIEW FROM THE CUSTOMER

Clarify customer complaints before inspection. First of all, perform an interview utilizing 

STC-20, "Diagnostic

Work Sheet"

 and reproduce symptoms as well as fully understand it. Ask customer about his/her complaints

carefully. Check symptoms by driving vehicle with customer, if necessary.

CAUTION:

Customers are not professional. Never guess easily like “maybe the customer means that...,” or

“maybe the customer mentions this symptom”.

>> GO TO 2.

2.

CHECK SYMPTOM

Reproduce the symptom that is indicated by the customer, based on the information from the customer

obtained by interview. Also check that the symptom is not caused by protection function. Refer to 

STC-13,

"Protection Function"

.

CAUTION:

When the symptom is caused by normal operation, fully inspect each portion and obtain the under-

standing of customer that the symptom is not caused by a malfunction.

>> GO TO 3.

3.

PERFORM SELF-DIAGNOSIS

 With CONSULT

Perform self-diagnosis.
Is any DTC detected?

YES

>> Record or print DTC and freeze frame data (FFD). GO TO 4.

NO

>> GO TO 6.

4.

RECHECK SYMPTOM

 With CONSULT

1. Erase self-diagnostic results.

2. Perform DTC confirmation procedures for the malfunctioning system.

NOTE:

If some DTCs are detected at the same time, determine the order for performing the diagnosis based on 

STC-

14, "DTC Inspection Priority Chart"

.

Is any DTC detected?

YES

>> GO TO 5.

NO

>> Check harness and connectors based on the information obtained by interview. Refer to 

GI-39,

"Intermittent Incident"

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5.

REPAIR OR REPLACE MALFUNCTIONING PARTS

• Repair or replace malfunctioning parts.

• Reconnect part or connector after repairing or replacing.

• When DTC is detected, erase self-diagnostic results for “EPS”.

>> GO TO 7.

6.

IDENTIFY MALFUNCTIONING SYSTEM BY SYMPTOM DIAGNOSIS

Estimate malfunctioning system based on symptom diagnosis and perform inspection.
Can the malfunctioning system be identified?

STC-20

< BASIC INSPECTION >

DIAGNOSIS AND REPAIR WORKFLOW

YES

>> GO TO 7.

NO

>> Check harness and connectors based on the information obtained by interview. Refer to 

GI-39,

"Intermittent Incident"

.

7.

FINAL CHECK

 With CONSULT

1. Check the reference value for EPS control unit.

2. Recheck the symptom and check that symptom is not reproduced on the same conditions.
Is the symptom reproduced?

YES

>> GO TO 3.

NO

>> Inspection End.

Diagnostic Work Sheet

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Description

• In general, customers have their own criteria for a problem. Therefore, it is important to understand the

symptom and status well enough by asking the customer about his/her concerns carefully. To systemize all

the information for the diagnosis, prepare the interview sheet referring to the interview points.

• In some cases, multiple conditions that appear simultaneously may cause a DTC to be detected.

Interview sheet sample

Interview sheet

Customer 
name

MR/MS

Registration 
number

Initial year 
registration 

Vehicle type

VIN

Storage date

Engine

Mileage

km (Mile)

Symptom

†

The steering wheel position (center) is in the wrong position.

†

EPS warning lamp turns on.

†

Noise

†

Vibration

†

Others

(

)

First occurrence

†

Recently

†

Others (

)

Frequency of occurrence

†

Always

†

Under a certain conditions of

†

Sometimes (time(s)/day)

Climate con-
ditions

†

Irrelevant

Weather

†

Fine

†

Cloud

†

Rain

†

Snow

†

Others (

)

Temperature

†

Hot

†

Warm

†

Cool

†

Cold

†

Temperature   Approx.

°C (°F)

Relative humidity

†

High

†

Moderate

†

Low

Road conditions

†

Urban area

†

Suburb area

†

High way

†

Mountain road (uphill or down hill)

†

Rough road

Operation conditions, etc.

†

Irrelevant

†

When engine starts

†

During idling

†

During driving

†

During acceleration

†

At constant speed driving

†

During deceleration

†

During cornering (right curve or left curve)

†

During steering

DIAGNOSIS AND REPAIR WORKFLOW

STC-21

< BASIC INSPECTION >

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Other conditions

Memo

Interview sheet

Customer 
name

MR/MS

Registration 
number

Initial year 
registration 

Vehicle type

VIN

Storage date

Engine

Mileage

km (Mile)

STC-22

< DTC/CIRCUIT DIAGNOSIS >

C1601 BATTERY POWER SUPPLY

DTC/CIRCUIT DIAGNOSIS

C1601 BATTERY POWER SUPPLY

DTC Logic

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DTC DETECTION LOGIC

DTC CONFIRMATION PROCEDURE

1.

PRECONDITIONING

If DTC CONFIRMATION PROCEDURE has been previously conducted, always turn ignition switch OFF and

wait at least 10 seconds before conducting the next test.

>> GO TO 2.

2.

DTC REPRODUCTION PROCEDURE

With CONSULT

1. Turn the ignition switch OFF to ON.

2. Perform EPS self-diagnosis.
Is DTC C1601 detected?

YES

>> Proceed to diagnosis procedure. Refer to 

STC-22, "Diagnosis Procedure"

.

NO

>> Inspection End.

Diagnosis Procedure

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Regarding Wiring Diagram information, refer to 

STC-15, "Wiring Diagram"

.

1.

CHECK EPS CONTROL UNIT GROUND CIRCUIT

1. Turn ignition switch OFF.

2. Disconnect EPS control unit harness connector.

3. Check continuity between EPS control unit harness connector terminal and ground.

4. Connect EPS control unit harness connector.
Is the inspection result normal?

YES

>> GO TO 2.

NO

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

2.

CHECK EPS CONTROL UNIT POWER SUPPLY CIRCUIT (1)

1. Check voltage between EPS control unit harness connector terminals and ground.

DTC

Display item

Malfunction detected condition

Possible cause

C1601

BATTERY VOLT

When a power supply voltage to the EPS control unit 
is maintained at 17.5 V or more or at less than 9 V 
continuously for five second or more.

• Harness or connector
• EPS control unit
• Fuse
• Power supply system
• Battery

EPS control unit

—

Continuity

Connector

Terminal

M37

10

Ground

Yes