ON BOARD DIAGNOSTIC (OBD) SYSTEM
EC-47
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EC
Revision: 2004 November
2004 Murano
ON BOARD DIAGNOSTIC (OBD) SYSTEM
PFP:00028
Introduction
ABS004AM
The ECM has an on board diagnostic system, which detects malfunctions related to engine sensors or actua-
tors. The ECM also records various emission-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-77
.)
Two Trip Detection Logic
ABS004AN
When a malfunction is detected for the first time, 1st trip 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” means a driving mode in which self-diagnosis is performed
during vehicle operation. Specific on board diagnostic items 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 cannot warn the driver by lighting MIL up when there is
malfunction on engine control system.
Therefore, when electrical controlled throttle and part of ECM related diagnoses are continuously detected as
NG for 5 trips, ECM warns the driver that engine control system malfunctions and MIL circuit is open by means
of operating fail-safe function.
Emission-related diagnostic information
SAE Mode
Diagnostic Trouble Code (DTC)
Mode 3 of SAE J1979
Freeze Frame data
Mode 2 of SAE J1979
System Readiness Test (SRT) code
Mode 1 of SAE J1979
1st Trip Diagnostic Trouble Code (1st Trip DTC)
Mode 7 of SAE J1979
1st Trip Freeze Frame data
Test values and Test limits
Mode 6 of SAE J1979
Calibration ID
Mode 9 of SAE J1979
DTC
1st trip DTC
Freeze Frame
data
1st trip Freeze
Frame data
SRT code
Test value
CONSULT-II
×
×
×
×
×
—
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 cata-
lyst damage) — DTC: P0300 -
P0306 is being detected
×
—
—
—
—
—
×
—
Misfire (Possible three way cata-
lyst damage) — DTC: P0300 -
P0306 is being detected
—
—
×
—
—
×
—
—
One trip detection diagnoses
(Refer to
EC-8
.)
—
×
—
—
×
—
—
—
Except above
—
—
—
×
—
×
×
—