Nissan Altima L32. Manual - part 225

DIAGNOSIS AND REPAIR WORK FLOW

EC-21

< BASIC INSPECTION >

[QR25DE FOR CALIFORNIA]

C

D

E

F

G

H

I

J

K

L

M

A

EC

N

P

O

1.

GET INFORMATION FOR SYMPTOM

Get the detailed information from the customer about the symptom (the condition and the environment when

the incident/malfunction occurred) using the “Diagnostic Work Sheet”. (Refer to 

EC-22, "Diagnostic Work

Sheet"

.)

>> GO TO 2.

2.

CHECK DTC

1. Check DTC.

2. Perform the following procedure if DTC is displayed.

-

Record DTC and freeze frame data. (Print them out with CONSULT-III or GST.)

-

Erase DTC. (Refer to 

EC-112, "Diagnosis Description"

.)

-

Study the relationship between the cause detected by DTC and the symptom described by the customer.

(Symptom Table is useful. Refer to 

EC-539, "Symptom Table"

.)

3. Check related service bulletins for information.
Is any symptom described and is any DTC detected?

Symptom is described, DTC is detected>>GO TO 3.

Symptom is described, DTC is not detected>>GO TO 4.

Symptom is not described, DTC is detected>>GO TO 5.

3.

CONFIRM THE SYMPTOM

Try to confirm the symptom described by the customer (except MIL ON).

Also study the normal operation and fail safe related to the symptom. Refer to 

EC-543, "Description"

 and 

EC-

523, "Fail Safe"

.

Diagnosis Work Sheet is useful to verify the incident.

Verify relation between the symptom and the condition when the symptom is detected.

>> GO TO 5.

4.

CONFIRM THE SYMPTOM

Try to confirm the symptom described by the customer.

Also study the normal operation and fail safe related to the symptom. Refer to 

EC-543, "Description"

 and 

EC-

523, "Fail Safe"

.

Diagnosis Work Sheet is useful to verify the incident.

Verify relation between the symptom and the condition when the symptom is detected.

>> GO TO 6.

5.

PERFORM DTC CONFIRMATION PROCEDURE

Perform DTC CONFIRMATION PROCEDURE for the displayed DTC, and then make sure that DTC is

detected again.

If two or more DTCs are detected, refer to 

EC-525, "DTC Inspection Priority Chart"

 and determine trouble

diagnosis order.

NOTE:

• Freeze frame data is useful if the DTC is not detected.

• Perform Component Function Check if DTC CONFIRMATION PROCEDURE is not included on Service

Manual. This simplified check procedure is an effective alternative though DTC cannot be detected during

this check.

If the result of Component Function Check is NG, it is the same as the detection of DTC by DTC CONFIR-

MATION PROCEDURE.

Is DTC detected?

YES

>> GO TO 10.

NO

>> Check according to 

EC-527, "DTC Index"

.

6.

PERFORM BASIC INSPECTION

Perform 

EC-24, "BASIC INSPECTION : Special Repair Requirement"

.

Do you have CONSULT-III?

EC-22

< BASIC INSPECTION >

[QR25DE FOR CALIFORNIA]

DIAGNOSIS AND REPAIR WORK FLOW

YES

>> GO TO 7.

NO

>> GO TO 9.

7.

PERFORM SPEC IN DATA MONITOR MODE

With CONSULT-III

Make sure that “MAS A/F SE-B1”, “B/FUEL SCHDL” and “A/F ALPHA-B1” are within the SP value using CON-

SULT-III in “SPEC” of “DATA MONITOR” mode. Refer to 

EC-136, "Component Function Check"

.

Is the measurement value within the SP value?

YES

>> GO TO 9.

NO

>> GO TO 8.

8.

DETECT MALFUNCTIONING PART BY TROUBLE DIAGNOSIS - SPECIFICATION VALUE

Detect malfunctioning part according to 

EC-137, "Diagnosis Procedure"

.

Is malfunctioning part detected?

YES

>> GO TO 11.

NO

>> GO TO 9.

9.

DETECT MALFUNCTIONING SYSTEM BY SYMPTOM TABLE

Detect malfunctioning system according to 

EC-539, "Symptom Table"

 based on the confirmed symptom in

step 4, and determine the trouble diagnosis order based on possible causes and symptom.

>> GO TO 10.

10.

DETECT MALFUNCTIONING PART BY DIAGNOSIS PROCEDURE

Inspect according to Diagnosis Procedure of the system.

NOTE:

The Diagnosis Procedure in EC section described based on open circuit inspection. A short circuit inspection

is also required for the circuit check in the Diagnosis Procedure. For details, refer to Circuit Inspection in 

GI-

45, "Circuit Inspection"

.

Is malfunctioning part detected?

YES

>> GO TO 11.

NO

>> Monitor input data from related sensors or check the voltage of related ECM terminals using CON-

SULT-III. Refer to 

EC-485, "Reference Value"

.

11.

REPAIR OR REPLACE THE MALFUNCTIONING PART

1. Repair or replace the malfunctioning part.

2. Reconnect parts or connectors disconnected during Diagnosis Procedure again after repair and replace-

ment.

3. Check DTC. If DTC is displayed, erase it. Refer to 

EC-112, "Diagnosis Description"

.

>> GO TO 12.

12.

FINAL CHECK

When DTC was detected in step 2, perform DTC CONFIRMATION PROCEDURE or Component Function

Check again, and then make sure that the malfunction have been repaired securely.

When symptom was described from the customer, refer to confirmed symptom in step 3 or 4, and make sure

that the symptom is not detected.
Is DTC detected and does symptom remain?

YES-1 >> DTC is detected: GO TO 10.

YES-2 >> Symptom remains: GO TO 6.

NO

>> Before returning the vehicle to the customer, make sure to erase unnecessary DTC in ECM and

TCM (Transmission Control Module). (Refer to 

EC-112, "Diagnosis Description"

.) If the comple-

tion of SRT is needed, drive vehicle under the specific DRIVING PATTERN in 

EC-530,

"How to Set SRT Code"

.

Diagnostic Work Sheet

INFOID:0000000004349125

DESCRIPTION

DIAGNOSIS AND REPAIR WORK FLOW

EC-23

< BASIC INSPECTION >

[QR25DE FOR CALIFORNIA]

C

D

E

F

G

H

I

J

K

L

M

A

EC

N

P

O

There are many operating conditions that lead to the malfunction of

engine components. A good grasp of such conditions can make trou-

bleshooting faster and more accurate.

In general, each customer feels differently about an incident. It is

important to fully understand the symptoms or conditions for a cus-

tomer complaint.

Utilize a diagnostic worksheet like the one on the WORKSHEET

SAMPLE in order to organize all the information for troubleshooting.

Some conditions may cause the MIL to come on steady or blink and

DTC to be detected. Examples:

• Vehicle ran out of fuel, which caused the engine to misfire.

• Fuel filler cap was left off or incorrectly screwed on, allowing fuel to

evaporate into the atmosphere.

WORKSHEET SAMPLE

SEF907L

MTBL0017

EC-24

< BASIC INSPECTION >

[QR25DE FOR CALIFORNIA]

INSPECTION AND ADJUSTMENT

INSPECTION AND ADJUSTMENT

BASIC INSPECTION
BASIC INSPECTION : Special Repair Requirement

INFOID:0000000004349126

1.

INSPECTION START

1. Check service records for any recent repairs that may indicate a related malfunction, or a current need for

scheduled maintenance.

2. Open engine hood and check the following:

-

Harness connectors for improper connections

-

Wiring harness for improper connections, pinches and cut

-

Vacuum hoses for splits, kinks and improper connections

-

Hoses and ducts for leaks

-

Air cleaner clogging

-

Gasket

3. Confirm that electrical or mechanical loads are not applied.

-

Headlamp switch is OFF.

-

Air conditioner switch is OFF.

-

Rear window defogger switch is OFF.

-

Steering wheel is in the straight-ahead position, etc.

4. Start engine and warm it up until engine coolant temperature

indicator points the middle of gauge.

Ensure engine stays below 1,000 rpm.

5. Run engine at about 2,000 rpm for about 2 minutes under no

load.

6. Make sure that no DTC is displayed with CONSULT-III or GST.
Is any DTC detected?

YES

>> GO TO 2.

NO

>> GO TO 3.

2.

REPAIR OR REPLACE

Repair or replace components as necessary according to corresponding Diagnostic Procedure.

>> GO TO 3

3.

CHECK TARGET IDLE SPEED

1. Run engine at about 2,000 rpm for about 2 minutes under no load.

SEF983U

SEF976U

SEF977U