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Nissan Titan A60. Manual - part 344

EC-42

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[VK56DE]

DIAGNOSIS SYSTEM (ECM)

*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.

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DIAGNOSIS SYSTEM (ECM)

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

• The A counter will be cleared when the malfunction is detected regardless of (1) - (4).

• The A counter will be counted up when (1) - (4) are satisfied without the same malfunction.

• The DTC will not be displayed after the A counter reaches 40.

Driving pattern B means operating vehicle operation as per the following:

All components and systems should be monitored at least once by the OBD system.

• The B counter will be cleared when the malfunction is detected once regardless of the driving pattern.

• The B counter will be counted up when driving pattern B is satisfied without any malfunctions.

• The MIL will turn OFF when the B counter reaches 3 (*2 in OBD SYSTEM OPERATION CHART).

*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.

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< SYSTEM DESCRIPTION >

[VK56DE]

DIAGNOSIS SYSTEM (ECM)

DIAGNOSIS DESCRIPTION : Driving Pattern

INFOID:0000000006471098

DRIVING PATTERN A

• The A counter will be cleared when the malfunction is detected regardless of (1) - (4).

• The A counter will be counted up when (1) - (4) are satisfied without the same malfunction.

• The DTC will not be displayed after the A counter reaches 40.

DRIVING PATTERN B

Driving pattern B means operating vehicle operation as per the following:

All components and systems should be monitored at least once by the OBD system.

• The B counter will be cleared when the malfunction is detected once regardless of the driving pattern.

• The B counter will be counted up when driving pattern B is satisfied without any malfunctions.

• The MIL will turn OFF when the B counter reaches 3.

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

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

±0.1) [%]

Engine coolant temperature (T) condition:

• When the freeze frame data shows lower than 70

°C (158°F), T should be lower than 70°C (158°F).

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

°C (158°F), T should be higher than or equal to

°C (158°F).

• The C counter will be cleared when the malfunction is detected regardless of vehicle conditions above.

• The C counter will be counted up when vehicle conditions above are satisfied without the same malfunction.

• The DTC will not be displayed after C counter reaches 80.

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

stored in ECM.

DIAGNOSIS DESCRIPTION : System Readiness Test (SRT) Code

INFOID:0000000006471099

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:

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DIAGNOSIS SYSTEM (ECM)

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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 MIL is ON 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”) and

DTC (No 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.

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”.

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”

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