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Nissan Frontier. Manual - part 370

DIAGNOSIS SYSTEM (ECM)

EC-51

< SYSTEM DESCRIPTION >

[QR25DE]

Driving Pattern C

Refer to

EC-52, "DIAGNOSIS DESCRIPTION : Driving Pattern"

Example:

If the stored freeze frame data is as per the following:

Engine speed: 850 rpm, Calculated load value: 30%, Engine coolant temperature: 80

°C (176°F)

To be satisfied with driving pattern C, the vehicle should run under the following conditions:

Engine speed: 475 – 1,225 rpm, Calculated load value: 27 – 33%, Engine coolant temperature: more than

°C (158°F)

Relationship Between MIL, DTC, 1st Trip DTC and Driving Patterns Except For “Misfire <Exhaust
Quality Deterioration>”, “Fuel Injection System”

JMBIA1418GB

EC-52

< SYSTEM DESCRIPTION >

[QR25DE]

DIAGNOSIS SYSTEM (ECM)

Explanation for Driving Patterns Except for “Misfire <Exhaust Quality Deterioration>”, “Fuel Injection
System”

Driving Pattern A

Refer to

EC-52, "DIAGNOSIS DESCRIPTION : Driving Pattern"

Driving Pattern B

Refer to

EC-52, "DIAGNOSIS DESCRIPTION : Driving Pattern"

DIAGNOSIS DESCRIPTION : Driving Pattern

INFOID:0000000009480740

CAUTION:

Always drive at a safe speed.

DRIVING PATTERN A

Driving pattern A means a trip satisfying the following conditions.

• Engine speed reaches 400 rpm or more.

• Engine coolant temperature rises by 20

°C (36°F) or more after starting the engine.

• Engine coolant temperature reaches 70

°C (158°F) or more.

• The ignition switch is turned from ON to OFF.

NOTE:

• When the same malfunction is detected regardless of driving conditions, reset the counter of driving pattern

• When the above conditions are satisfied without detecting the same malfunction, reset the counter of driving

pattern A.

DRIVING PATTERN B

Driving pattern B means a trip satisfying the following conditions.

• Engine speed reaches 400 rpm or more.

• Engine coolant temperature reaches 70

°C (158°F) or more.

• Vehicle speed of 70 – 120 km/h (44 – 75 MPH) is maintained for 60 seconds or more under the control of

closed loop.

• Vehicle speed of 30 – 60 km/h (19 – 37 MPH) is maintained for 10 seconds or more under the control of

closed loop.

• Under the closed loop control condition, the following state reaches 12 seconds or more in total: Vehicle

speed of 4 km/h (2 MPH) or less with idling condition.

• The state of driving at 10 km/h (7 MPH) or more reaches 10 minutes or more in total.

• A lapse of 22 minutes or more after engine start.

NOTE:

• Drive the vehicle at a constant velocity.

• When the same malfunction is detected regardless of driving conditions, reset the counter of driving pattern

• When the above conditions are satisfied without detecting the same malfunction, reset the counter of driving

pattern B.

DRIVING PATTERN C

Driving pattern C means operating vehicle as per the following:

The following conditions should be satisfied at the same time:

Engine speed: (Engine speed in the freeze frame data)

±375 rpm

*1: When the same malfunction is de-

tected in two consecutive trips, MIL
will light up.

*2: MIL will turn OFF after vehicle is driv-

en 3 times (pattern B) without any
malfunctions.

*3: When the same malfunction is de-

tected in two consecutive trips, the
DTC and the freeze frame data will be
stored in ECM.

*4: The DTC and the freeze frame data

will not be displayed any longer after
vehicle is driven 40 times (pattern A)
without the same malfunction.
(The DTC and the freeze frame data
still remain in ECM.)

*5: When a malfunction is detected for

the first time, the 1st trip DTC and the
1st trip freeze frame data will be
stored in ECM.

*6: 1st trip DTC will be cleared after vehi-

cle is driven once (pattern B) without
the same malfunction.

*7: When the same malfunction is de-

tected in the 2nd trip, the 1st trip
freeze frame data will be cleared.

DIAGNOSIS SYSTEM (ECM)

EC-53

< SYSTEM DESCRIPTION >

[QR25DE]

Calculated load value: (Calculated load value in the freeze frame data) x (1

±0.1) [%]

Engine coolant temperature condition:

• When the freeze frame data shows lower than 70

°C (158°F), engine coolant temperature should be lower

than 70

°C (158°F).

• When the freeze frame data shows higher than or equal to 70

°C (158°F), engine coolant temperature should

be higher than or equal to 70

°C (158°F).

NOTE:

• When the same malfunction is detected regardless of the above vehicle conditions, reset the counter of driv-

ing pattern C.

• When the above conditions are satisfied without detecting the same malfunction, reset the counter of driving

pattern C.

• The 1st trip DTC will be cleared when C counter is counted once without the same malfunction after DTC is

stored in ECM.

DRIVING PATTERN D

Driving pattern D means a trip satisfying the following conditions.

• The state of driving at 40 km/h (25 MPH) reaches 300 seconds or more in total.

• Idle speed lasts 30 seconds or more.

• A lapse of 600 seconds or more after engine start.

NOTE:

• When the same malfunction is detected regardless of driving conditions, reset the counter of driving pattern

• When the above conditions are satisfied without detecting the same malfunction, reset the counter of driving

pattern D.

DIAGNOSIS DESCRIPTION : System Readiness Test (SRT) Code

INFOID:0000000009480741

System Readiness Test (SRT) code is specified in Service $01 of SAE J1979/ISO 15031-5.

As part of an enhanced emissions test for Inspection & Maintenance (I/M), certain states require the status of

SRT be used to indicate whether the ECM has completed self-diagnosis of major emission systems and com-

ponents. Completion must be verified in order for the emissions inspection to proceed.

If a vehicle is rejected for a State emissions inspection due to one or more SRT items indicating “INCMP”, use

the information in this Service Manual to set the SRT to “CMPLT”.

In most cases the ECM will automatically complete its self-diagnosis cycle during normal usage, and the SRT

status will indicate “CMPLT” for each application system. Once set as “CMPLT”, the SRT status remains

“CMPLT” until the self-diagnosis memory is erased.

Occasionally, certain portions of the self-diagnostic test may not be completed as a result of the customer's

normal driving pattern; the SRT will indicate “INCMP” for these items.

NOTE:

The SRT will also indicate “INCMP” if the self-diagnosis memory is erased for any reason or if the ECM mem-

ory power supply is interrupted for several hours.

If, during the state emissions inspection, the SRT indicates “CMPLT” for all test items, the inspector will con-

tinue with the emissions test. However, if the SRT indicates “INCMP” for one or more of the SRT items the

vehicle is returned to the customer untested.

NOTE:

If permanent DTC is stored or MIL illuminates during the state emissions inspection, the vehicle is also

returned to the customer untested even though the SRT indicates “CMPLT” for all test items. Therefore, it is

important to check SRT (“CMPLT”), DTC (No DTCs) and permanent DTC (NO permanent DTCs) before the

inspection.

SRT SET TIMING

SRT is set as “CMPLT” after self-diagnosis has been performed one or more times. Completion of SRT is

done regardless of whether the result is OK or NG. The set timing is different between OK and NG results and

is shown in the table below.

EC-54

< SYSTEM DESCRIPTION >

[QR25DE]

DIAGNOSIS SYSTEM (ECM)

OK: Self-diagnosis is carried out and the result is OK.
NG: Self-diagnosis is carried out and the result is NG.
—: Self-diagnosis is not carried out.

When all SRT related self-diagnoses show OK results in a single cycle (Ignition OFF-ON-OFF), the SRT will

indicate “CMPLT”.

→ Case 1 above

When all SRT related self-diagnoses show OK results through several different cycles, the SRT will indicate

“CMPLT” at the time the respective self-diagnoses have at least one OK result.

→ Case 2 above

If one or more SRT related self-diagnoses show NG results in 2 consecutive cycles, the SRT will also indicate

“CMPLT”.

→ Case 3 above

The table above shows that the minimum number of cycles for setting SRT as “INCMP” is the number one (1)

for each self-diagnosis (Case 1 & 2) or the number two (2) for one of self-diagnoses (Case 3). However, in

preparation for the state emissions inspection, it is unnecessary for each self-diagnosis to be executed twice

(Case 3) for the following reasons:

• The SRT will indicate “CMPLT” at the time the respective self-diagnoses have one (1) OK result.

• The emissions inspection requires “CMPLT” of the SRT only with OK self-diagnosis results.

• During SRT driving pattern, the 1st trip DTC (NG) is detected prior to “CMPLT” of SRT and the self-diagnosis

memory must be erased from the ECM after repair.

• If the 1st trip DTC is erased, all the SRT will indicate “INCMP”.

NOTE:

SRT can be set as “CMPLT” together with the DTC(s). Therefore, DTC check must always be carried out

prior to the state emission inspection even though the SRT indicates “CMPLT”.

DIAGNOSIS DESCRIPTION : Permanent Diagnostic Trouble Code (Permanent DTC)

INFOID:0000000009480742

Permanent DTC is defined in SAE J1979/ISO 15031-5 Service $0A.

ECM stores a DTC issuing a command of turning on MIL as a permanent DTC and keeps storing the DTC as

a permanent DTC until ECM judges that there is no presence of malfunction.

Permanent DTCs cannot be erased by using the Erase function of CONSULT or Generic Scan Tool (GST) and

by disconnecting the battery to shut off power to ECM. This prevents a vehicle from passing the state emission

inspection without repairing a malfunctioning part.

When not passing the state emission inspection due to more than one permanent DTC, permanent DTCs

should be erased, referring to this manual.

NOTE:

• The important items in state emission inspection are that MIL is not ON, SRT test items are set, and perma-

nent DTCs are not included.

• Permanent DTCs do not apply for regions that permanent DTCs are not regulated by law.

Self-diagnosis result

Example

Diagnosis

Ignition cycle

← ON → OFF ← ON → OFF ← ON → OFF ← ON →

All OK

Case 1

P0400

OK (1)

— (1)

OK (2)

— (2)

P0402

OK (1)

— (1)

OK (2)

P1402

OK (1)

OK (2)

— (2)

SRT of EGR

“CMPLT”

Case 2

P0400

OK (1)

— (1)

P0402

— (0)

OK (1)

— (1)

P1402

OK (1)

OK (2)

— (2)

SRT of EGR

“INCMP”

“CMPLT”

NG exists

Case 3

P0400

—

P0402

—

P1402

—

(Consecutive

NG)

(1st trip)

DTC

1st trip DTC

—

1st trip DTC

DTC

(= MIL ON)

SRT of EGR

“INCMP”

“CMPLT”

Content .. 368 369 370 371 ..