Infiniti FX35, FX50 (S51). Manual - part 643

ON BOARD DIAGNOSTIC (OBD) SYSTEM

EC-113

< SYSTEM DESCRIPTION >

[VQ35HR]

(CONSULT-III also displays the malfunctioning component or system.)

No Tools

The number of blinks of the MIL in the Diagnostic Test Mode II (Self-Diagnostic Results) indicates the DTC.
Example: 0340, 0850, 1148, etc.
These DTCs are controlled by NISSAN.
• 1st trip DTC No. is the same as DTC No.
• Output of a DTC indicates a malfunction. However, GST and the Diagnostic Test Mode II do not indi-

cate whether the malfunction is still occurring or has occurred in the past and has returned to nor-
mal. CONSULT-III can identify malfunction status as shown below. Therefore, using CONSULT-III (if
available) is recommended.

DTC or 1st trip DTC of a malfunction is displayed in SELF-DIAGNOSTIC RESULTS mode of CONSULT-III.
Time data indicates how many times the vehicle was driven after the last detection of a DTC.
If the DTC is being detected currently, the time data will be [0].
If a 1st trip DTC is stored in the ECM, the time data will be [1t].

How to Erase DTC and 1st Trip DTC

With CONSULT-III

NOTE:
• If the ignition switch stays ON after repair work, be sure to turn ignition OFF once. Wait at least 10 seconds

and then turn it ON (engine stopped) again.

• If the DTC is not for A/T related items (see

EC-541, "DTC Index"

), skip step 1.

Erase DTC in TCM. Refer to

TM-61, "Diagnosis Description"

Select “ENGINE” with CONSULT-III.

Select “SELF-DIAG RESULTS”.

Touch “ERASE”. (DTC in ECM will be erased.)

With GST

NOTE:
• If the ignition switch stays ON after repair work, be sure to turn ignition switch OFF once. Wait at

least 10 seconds and then turn it ON (engine stopped) again.

Select Service $04 with GST (Generic Scan Tool).

No Tools

NOTE:
• If the ignition switch stays ON after repair work, be sure to turn ignition switch OFF once.

Wait at least 10 seconds and then turn it ON (engine stopped) again.

Erase DTC in ECM. Refer to How To ERASE DIAGNOSTIC TEST MODE II (SELF-DIAGNOSTIC
RESULTS).

• If the battery is disconnected, the emission-related diagnostic information will be cleared within 24

hours.

• The following data are cleared when the ECM memory is erased.
- Diagnostic trouble codes
- 1st trip diagnostic trouble codes
- Freeze frame data
- 1st trip freeze frame data
- System readiness test (SRT) codes
- Test values
Actual work procedures are explained using a DTC as an example. Be careful so that not only the DTC, but all
of the data listed above, are cleared from the ECM memory during work procedures.

SYSTEM READINESS TEST (SRT) CODE

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.

EC-114

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[VQ35HR]

ON BOARD DIAGNOSTIC (OBD) SYSTEM

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 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 Item

The table below shows required self-diagnostic items to set the SRT to “CMPLT”.

*: If completion of several SRTs is required, perform driving patterns (DTC confirmation procedure), one by one based on the priority for
models with CONSULT-III.

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.

SRT item

(CONSULT-III indication)

Performance

Priority*

Required self-diagnostic items to set the SRT to “CMPLT”

Corresponding

DTC No.

CATALYST

Three way catalyst function

P0420, P0430

EVAP SYSTEM

EVAP control system purge flow monitoring

P0441

EVAP control system

P0442

EVAP control system

P0456

HO2S

Air fuel ratio (A/F) sensor 1

P0133, P0153

Heated oxygen sensor 2

P0137, P0157

Heated oxygen sensor 2

P0138, P0158

Heated oxygen sensor 2

P0139, P0159

Self-diagnosis result

Example

Diagnosis

Ignition cycle

←

→

OFF

←

→

OFF

←

→

OFF

←

→

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”

ON BOARD DIAGNOSTIC (OBD) SYSTEM

EC-115

< SYSTEM DESCRIPTION >

[VQ35HR]

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”.

SRT Service Procedure

If a vehicle has failed the state emissions inspection due to one or more SRT items indicating “INCMP”, review
the flowchart diagnostic sequence on the next figure.

EC-116

< SYSTEM DESCRIPTION >

[VQ35HR]

ON BOARD DIAGNOSTIC (OBD) SYSTEM

How to Display SRT Status

WITH CONSULT-III

Selecting “SRT STATUS” in “DTC CONFIRMATION” mode with CONSULT-III.
For items whose SRT codes are set, “CMPLT” is displayed on the CONSULT-III screen; for items whose SRT
codes are not set, “INCMP” is displayed.
NOTE:
Though displayed on the CONSULT-III screen, “HO2S HTR” is not SRT item.

WITH GST

Selecting Service $01 with GST (Generic Scan Tool)

NO TOOLS

A SRT code itself cannot be displayed, however SRT status can.

Turn ignition switch ON and wait 20 seconds.

SRT status is indicated as shown below.
• When all SRT codes are set, MIL illuminates continuously.

JMBIA1574GB

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