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ON BOARD DIAGNOSTIC (OBD) SYSTEM
Introduction INFOID:0000000004537038
The ECM has an on board diagnostic system, which detects malfunctions related to engine sensors or actua-
tors. The ECM also records various emis sion-related diagnostic information including:
The above information can be checked using procedures listed in the table below. ×: Applicable —: Not applicable
*: When DTC and 1st trip DTC simultaneously appear on the display, they cannot be clearly distinguished from each other.
The malfunction indicator lamp (MIL) on the instrument panel lights up when the same malfunction is detected
in two consecutive trips (Two trip detection logic), or when the ECM enters fail-safe mode.
(Refer to EC-582, " Fail-Safe Chart " .)
Two Trip Detection Logic INFOID:0000000004537039
When a malfunction is detected for the first time, 1st tr ip DTC and 1st trip Freeze Frame data are stored in the
ECM memory. The MIL will not light up at this stage. <1st trip>
If the same malfunction is detected again during the next drive, the DTC and Freeze Frame data are stored in
the ECM memory, and the MIL lights up. The MIL lights up at the same time when the DTC is stored. <2nd
trip> The “trip” in the “Two Trip Detection Logic” m eans a driving mode in which self-diagnosis is performed
during vehicle operation. Specific on board diagnostic item s will cause the ECM to light up or blink the MIL,
and store DTC and Freeze Frame data, even in the 1st trip, as shown below.
×: Applicable —: Not applicable
When there is an open circuit on MIL circuit, the ECM c annot warn the driver by MIL lighting up when there is
malfunction on engine control system. Emission-related diagnostic information Diagnostic service
Diagnostic Tr ouble Code (DTC) Service $03 of SAE J1979
Freeze Frame data Service $02 of SAE J1979
System Readiness Test (SRT) code Service $01 of SAE J1979
1st Trip Diagnostic Trou ble Code (1st Trip DTC) Service $07 of SAE J1979
1st Trip Freeze Frame data
Test values and Test limi ts Service $06 of SAE J1979
Calibration ID Servic e $09 of SAE J1979
DTC 1st trip DTC Freeze Frame
data 1st trip Freeze
Frame data SRT code SRT status Test value
CONSULT-III × × × × × × —
GST × × × —× × ×
ECM × ×* — — — ×— Items
MIL DTC 1st trip DTC
1st trip 2nd trip 1st trip
displaying 2nd trip
displaying 1st trip
displaying 2nd trip
display-
ing
Blinking Lighting
up Blinking
Lighting
up
Misfire (Possible three way catalyst
damage) — DTC: P0300 - P0304 is
being detected ×
— — — — — ×—
Misfire (Possible three way catalyst
damage) — DTC: P0300 - P0304 is
being detected — —
×— — ×— —
One trip detection diagnoses
(Refer to EC-542, " Emission-relat-
ed Diagnostic Information " .)
—
×— — ×— — —
Except above — — — ×— × × —
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*1: 1st trip DTC No. is
the same as DTC No.
*2: This number is prescribed by SAE J2012.
*3: In Diagnostic Test Mode II (Self-diagnostic results), this number is controlled by NISSAN.
*4: The troubleshooting for this DTC needs CONSULT-III.
*5: When the ECM in the mode of displaying SRT status, MIL may flash. For the details, refer to "How to Display SRT Status".
*6: SRT code will not be set if the self-diagnostic result is NG.
*7: When the fail-safe operations for both self-diagnoses occur, the MIL illuminates.
DTC AND 1ST TRIP DTC The 1st trip DTC (whose number is the same as the DT C number) is displayed for the latest self-diagnostic
result obtained. If the ECM memory was cleared previously , and the 1st trip DTC did not recur, the 1st trip DTC
will not be displayed.
If a malfunction is detected during the 1st trip, the 1st trip DTC is stored in the ECM memory. The MIL will not
light up (two trip detection logic). If the same malfunc tion is not detected in the 2nd trip (meeting the required
driving pattern), the 1st trip DTC is cleared from the ECM memory. If the same malfunction is detected in the
2nd trip, both the 1st trip DTC and DTC are stored in t he ECM memory and the MIL lights up. In other words,
the DTC is stored in the ECM memory and the MIL light s up when the same malfunction occurs in two consec-
utive trips. If a 1st trip DTC is stored and a non-diagnostic operation is performed between the 1st and 2nd
trips, only the 1st trip DTC will continue to be stored. Fo r malfunctions that blink or light up the MIL during the
1st trip, the DTC and 1st trip DTC are stored in the ECM memory.
Procedures for clearing the DTC and the 1st trip DT C from the ECM memory are described in "HOW TO
ERASE EMISSION-RELATED DIAGNOSTIC INFORMATION".
For malfunctions in which 1st trip DTCs are displa yed, refer to "EMISSION-RELATED DIAGNOSTIC INFOR-
MATION ITEMS". These items are required by legal r egulations to continuously monitor the system/compo-
nent. In addition, the items monitored non-cont inuously are also displayed on CONSULT-III.
1st trip DTC is specified in Service $07 of SAE J1979. 1st trip DTC detection occurs without lighting up the MIL
and therefore does not warn the driver of a malfunction. However, 1st trip DTC detection will not prevent the
vehicle from being tested, for example during Inspection/Maintenance (I/M) tests.
When a 1st trip DTC is detected, check, print out or write down and erase (1st trip) DTC and Freeze Frame
data as specified in Work Flow procedure Step 2, refer to EC-577, " Trouble Diagnosis Introduction " . Then per-
form DTC Confirmation Procedure or Overall Function Che ck to try to duplicate the malfunction. If the mal-
function is duplicated, the item requires repair.
How to Read DTC and 1st Trip DTC DTC and 1st trip DTC can be read by the following methods.
WITH CONSULT-III
WITH GST
CONSULT-III or GST (Generic Scan Tool ) Examples: P0340, P0850, P1148, etc.
These DTCs are prescribed by SAE J2012.
(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. ETC MOT-B1 P2118 2118 — 1
×EC-935 ETC ACTR-B1 P2119 2119 — 1
×EC-940 APP SEN 1/CIRC P2122 2122 — 1
×EC-942 APP SEN 1/CIRC P2123 2123 — 1
×EC-942 APP SEN 2/CIRC P2127 2127 — 1
×EC-947 APP SEN 2/CIRC P2128 2128 — 1
×EC-947 TP SENSOR-B1 P2135 2135 — 1
×EC-954 APP SENSOR P2138 2138 — 1
×EC-959 A/F SENSOR1 (B1) P2A00 2A00 — 2
×EC-966 Items
(CONSULT-III screen terms) DTC*
1
SRT code Trip MIL lighting up Reference page
CONSULT-III
GST* 2
ECM*3
EC-548< SERVICE INFOMATION >
[MR TYPE 1]
ON BOARD DIAGNOSTIC (OBD) SYSTEM
If one or more SRT related self-diagnoses showed NG resu lts in 2 consecutive cycles, the SRT will also indi-
cate “CMPLT”. → Case 3 above
The table above shows that the minimum number of cycl es for setting SRT as “INCMP” is one (1) for each
self-diagnosis (Case 1 & 2) or two (2) for one of self-diagnoses (Case 3). However, in preparation for the state
emissions inspection, it is unnecessary for each self-d iagnosis 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.
• When, during SRT driving pattern, 1st trip DTC (NG) is detected prior to “CMPLT” of SRT, the self-diagnosis
memory must be erased from 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 page.
How to Display SRT Status WITH CONSULT-III JMBIA1574GB
ON BOARD DIAGNOSTIC (OBD) SYSTEM
EC-549
< SERVICE INFOMATION >
[MR TYPE 1] C
D E
F
G H
I
J
K L
M A EC
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Selecting “SRT STATUS” in “DTC & SR
T ONFIRMATION” mode with CONSULT-III.
For items whose SRT codes are set, a “CMPLT” is di splayed on the CONSULT-III screen; for items whose
SRT codes are not set, “INCMP” is displayed.
NOTE:
Though displayed on the CONSULT-III scr een, “HO2S HTR” is not SRT item.
WITH GST
Selecting Service $01 with GST (Generic Scan Tool)
NO TOOLS
A SRT code itself can not be displayed while only SRT status can be.
1. Turn ignition switch ON and wait 20 seconds.
2. SRT status is indicated as shown below. • When all SRT codes are set, MIL lights up continuously.
• When any SRT codes are not set, MIL will flash periodically for 10 seconds.
How to Set SRT Code To set all SRT codes, self-diagnosis for the items indicated above must be performed one or more times. Each
diagnosis may require a long period of actual driving under various conditions.
WITH CONSULT-III
Perform corresponding DTC Confirmation Procedure one by one based on Performance Priority in the table
on "SRT Item".
WITHOUT CONSULT-III
The most efficient driving pattern in which SRT codes can be properly set is explained on the next page. The
driving pattern should be performed one or more times to set all SRT codes. PBIB2317E
Item
OBD-
MID Self-diagnostic test item DTC Test value and Test
limit
(GST display) Description
TID Unit and
Scaling ID
HO2S 01H
Air fuel ratio (A/F) sensor 1
(Bank 1) P0131 83H 0BH
Minimum sensor output voltage for test
cycle
P0131 84H 0BH Maximum sensor output voltage for test
cycle
P0130 85H 0BH Minimum sensor output voltage for test
cycle
P0130 86H 0BH Maximum sensor output voltage for test
cycle
P0133 87H 04H Response rate: Response ratio (Lean to
Rich)
P0133 88H 04H Response rate: Response ratio (Rich to
Lean)
P2A00 89H 84H The amount of shift in air fuel ratio
P2A00 8AH 84H The amount of shift in air fuel ratio P0130 8BH 0BH Difference in sensor output voltage
P0133 8CH 83H Response gain at the limited frequency
02H Heated oxygen sensor 2
(Bank 1) P0138 07H 0CH
Minimum sensor output voltage for test
cycle
P0137 08H 0CH Maximum sensor output voltage for test
cycle
P0138 80H 0CH Sensor output voltage
P0139 81H 0CH Difference in sensor output voltage
03H Heated oxygen sensor 3
(Bank 1) P0143 07H 0CH
Minimum sensor output voltage for test
cycle
P0144 08H 0CH Maximum sensor output voltage for test
cycle
P0146 80H 0CH Sensor output voltage
P0145 81H 0CH Difference in sensor output voltage
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HO2S
05H
Air fuel ratio (A/F) sensor 1
(Bank 2) P0151 83H 0BH
Minimum sensor output voltage for test
cycle
P0151 84H 0BH Maximum sensor output voltage for test
cycle
P0150 85H 0BH Minimum sensor output voltage for test
cycle
P0150 86H 0BH Maximum sensor output voltage for test
cycle
P0153 87H 04H Response rate: Response ratio (Lean to
Rich)
P0153 88H 04H Response rate: Response ratio (Rich to
Lean)
P2A03 89H 84H The amount of shift in air fuel ratio
P2A03 8AH 84H The amount of shift in air fuel ratio P0150 8BH 0BH Difference in sensor output voltage
P0153 8CH 83H Response gain at the limited frequency
06H Heated oxygen sensor 2
(Bank 2) P0158 07H 0CH
Minimum sensor output voltage for test
cycle
P0157 08H 0CH Maximum sensor output voltage for test
cycle
P0158 80H 0CH Sensor output voltage
P0159 81H 0CH Difference in sensor output voltage
07H Heated oxygen sensor 3
(Bank2) P0163 07H 0CH
Minimum sensor output voltage for test
cycle
P0164 08H 0CH Maximum sensor output voltage for test
cycle
P0166 80H 0CH Sensor output voltage
P0165 81H 0CH Difference in sensor output voltage
CATA-
LYST 21H
Three way catalyst function
(Bank1) P0420 80H 01H O2 storage index
P0420 82H 01H Switching time lag engine exhaust index
value
P2423 83H 0CH Difference in 3rd O2 sensor output volt-
age
P2423 84H 84H O2 storage index in HC trap catalyst
22H Three way catalyst function
(Bank2) P0430 80H 01H O2 storage index
P0430 82H 01H Switching time lag engine exhaust index
value
P2424 83H 0CH Difference in 3rd O2 sensor output volt-
age
P2424 84H 84H O2 storage index in HC trap catalyst
Item
OBD-
MID Self-diagnostic test item DTC Test value and Test
limit
(GST display) Description
TID Unit and
Scaling ID
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FUEL
SYSTEM 81H
Fuel injection system function
(Bank 1) P0171 or P0172 80H 2FH Long term fuel trim
P0171 or P0172 81H 24H The number of lambda control clamped
82H Fuel injection system function
(Bank 2) P0174 or P0175 80H 2FH Long term fuel trim
P0174 or P0175 81H 24H The number of lambda control clamped
MISFIRE A1H Multiple Cylinder Misfire P0301 80H 24H
Misfiring counter at 1000rev of the first
cylinder
P0302 81H 24H Misfiring counter at 1000rev of the sec-
ond cylinder
P0303 82H 24H Misfiring counter at 1000rev of the third
cylinder
P0304 83H 24H Misfiring counter at 1000rev of the
fourth cylinder
P0305 84H 24H Misfiring counter at 1000rev of the fifth
cylinder
P0306 85H 24H Misfiring counter at 1000rev of the sixth
cylinder
P0307 86H 24H Misfiring counter at 1000rev of the sev-
enth cylinder
P0308 87H 24H Misfiring counter at 1000rev of the
eighth cylinder
P0300 88H 24H Misfiring counter at 1000rev of the mul-
tiple cylinders
P0301 89H 24H Misfiring counter at 200rev of the first
cylinder
P0302 8AH 24H Misfiring counter at 200rev of the sec-
ond cylinder
P0303 8BH 24H Misfiring counter at 200rev of the third
cylinder
P0304 8CH 24H Misfiring counter at 200rev of the fourth
cylinder
P0305 8DH 24H Misfiring counter at 200rev of the fifth
cylinder
P0306 8EH 24H Misfiring counter at 200rev of the fifth
cylinder
P0307 8FH 24H Misfiring counter at 200rev of the fifth
cylinder
P0308 90H 24H Misfiring counter at 200rev of the fifth
cylinder
P0300 91H 24H Misfiring counter at 1000rev of the sin-
gle cylinder
P0300 92H 24H Misfiring counter at 200rev of the single
cylinder
P0300 93H 24H Misfiring counter at 200rev of the multi-
ple cylinders
Item
OBD-
MID Self-diagnostic test item DTC Test value and Test
limit
(GST display) Description
TID Unit and
Scaling ID
), skip step 1.
1. Erase DTC in TCM.
2. Select "ENGINE" with CONSULT-III.
3. Select "SELF-DIAG RESULTS". MISFIRE
A2H No.1 Cylinder Misfire
P0301 0BH 24H
EWMA (Exponential Weighted Moving
Average) misfire counts for last 10 driv-
ing cycles
P0301 0CH 24H Misfire counts for last/current driving cy-
cles
A3H No.2 Cylinder Misfire P0302 0BH 24H
EWMA (Exponential Weighted Moving
Average) misfire counts for last 10 driv-
ing cycles
P0302 0CH 24H Misfire counts for last/current driving cy-
cles
A4H No.3 Cylinder Misfire P0303 0BH 24H
EWMA (Exponential Weighted Moving
Average) misfire counts for last 10 driv-
ing cycles
P0303 0CH 24H Misfire counts for last/current driving cy-
cles
A5H No.4 Cylinder Misfire P0304 0BH 24H
EWMA (Exponential Weighted Moving
Average) misfire counts for last 10 driv-
ing cycles
P0304 0CH 24H Misfire counts for last/current driving cy-
cles
A6H No.5 Cylinder Misfire P0305 0BH 24H
EWMA (Exponential Weighted Moving
Average) misfire counts for last 10 driv-
ing cycles
P0305 0CH 24H Misfire counts for last/current driving cy-
cles
A7H No.6 Cylinder Misfire P0306 0BH 24H
EWMA (Exponential Weighted Moving
Average) misfire counts for last 10 driv-
ing cycles
P0306 0CH 24H Misfire counts for last/current driving cy-
cles
A8H No.7 Cylinder Misfire P0307 0BH 24H
EWMA (Exponential Weighted Moving
Average) misfire counts for last 10 driv-
ing cycles
P0307 0CH 24H Misfire counts for last/current driving cy-
cles
A9H No.8 Cylinder Misfire P0308 0BH 24H
EWMA (Exponential Weighted Moving
Average) misfire counts for last 10 driv-
ing cycles
P0308 0CH 24H Misfire counts for last/current driving cy-
cles
Item
OBD-
MID Self-diagnostic test item DTC Test value and Test
limit
(GST display) Description
TID Unit and
Scaling ID