Nissan Versa

 Sedan Service Manual

Engine » Engine control system (EC) » Diagnosis description
Diagnosis description : system readiness test (SRT) code

System Readiness Test (SRT) code is specified in Service $01 of SAE J1979/ISO 150315.

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 selfdiagnosis of major emission systems and components.

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 selfdiagnosis 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 selfdiagnosis memory is erased.

Occasionally, certain portions of the selfdiagnostic 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 selfdiagnosis memory is erased for any reason or if the ECM memory power supply is interrupted for several hours.

If, during the state emissions inspection, the SRT indicates "CMPLT" for all test items, the inspector will continue 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 DTC) before the inspection.

SRT SET TIMING

SRT is set as "CMPLT" after selfdiagnosis 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: Selfdiagnosis is carried out and the result is OK.

-: Selfdiagnosis is not carried out.

When all SRT related selfdiagnoses show OK results in a single cycle (Ignition OFFONOFF), the SRT will indicate "CMPLT". → Case 1 above When all SRT related selfdiagnoses show OK results through several different cycles, the SRT will indicate "CMPLT" at the time the respective selfdiagnoses have at least one OK result. → Case 2 above If one or more SRT related selfdiagnoses 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 selfdiagnosis (Case 1 & 2) or the number two (2) for one of selfdiagnoses (Case 3). However, in preparation for the state emissions inspection, it is unnecessary for each selfdiagnosis to be executed twice (Case 3) for the following reasons:

• The SRT will indicate "CMPLT" at the time the respective selfdiagnoses have one (1) OK result.
• The emissions inspection requires "CMPLT" of the SRT only with OK selfdiagnosis results.
• During SRT driving pattern, the 1st trip DTC (NG) is detected prior to "CMPLT" of SRT and the selfdiagnosis 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 : 1st trip detection logic and two trip detection logic

Diagnosis description : dtc and freeze frame data

Diagnosis description : counter system

Diagnosis description : driving pattern

Diagnosis description : system readiness test (SRT) code

Diagnosis description : permanent diagnostic trouble code (permanent DTC)

Diagnosis description : malfunction indicator lamp (MIL)

On Board Diagnosis Function

Consult function