AT-44
[RE4F04B]
ON BOARD DIAGNOSTIC SYSTEM DESCRIPTION
Revision: November 2006
2006 Altima
ON BOARD DIAGNOSTIC SYSTEM DESCRIPTION
PFP:00000
Introduction
ECS0095Z
The A/T system has two self-diagnostic systems.
The first is the emission-related on board diagnostic system (OBD-II) performed by the TCM (transaxle control
module) in combination with the ECM. The malfunction is indicated by the MIL (malfunction indicator lamp)
and is stored as a DTC in the ECM memory but not the TCM memory.
The second is the TCM original self-diagnosis indicated by the A/T check (position) indicator lamp. The mal-
function is stored in the TCM memory. The detected items are overlapped with OBD-II self-diagnostic items.
For details, refer to
AT-44, "OBD-II Function for A/T System"
.
OBD-II Function for A/T System
ECS00960
The ECM provides emission-related on board diagnostic (OBD-II) functions for the A/T system. One function
is to receive a signal from the TCM used with OBD-related parts of the A/T system. The signal is sent to the
ECM when a malfunction occurs in the corresponding OBD-related part. The other function is to indicate a
diagnostic result by means of the MIL (malfunction indicator lamp) on the instrument panel. Sensors, switches
and solenoid valves are used as sensing elements.
The MIL automatically illuminates in One or Two Trip Detection Logic when a malfunction is sensed in relation
to A/T system parts.
One or Two Trip Detection Logic of OBD-II
ECS00961
ONE TRIP DETECTION LOGIC
If a malfunction is sensed during the first test drive, the MIL will illuminate and the malfunction will be stored in
the ECM memory as a DTC. The TCM is not provided with such a memory function.
TWO TRIP DETECTION LOGIC
When a malfunction is sensed during the first test drive, it is stored in the ECM memory as a 1st trip DTC
(diagnostic trouble code) or 1st trip freeze frame data. At this point, the MIL will not illuminate. — First Trip
If the same malfunction as that experienced during the first test drive is sensed during the second test drive,
the MIL will illuminate. — Second Trip
A/T-related parts for which the MIL illuminates during the first or second test drive are listed below.
The “trip” in the “One or Two Trip Detection Logic” means a driving mode in which self-diagnosis is performed
during vehicle operation.
OBD-II Diagnostic Trouble Code (DTC)
ECS00962
HOW TO READ DTC AND 1ST TRIP DTC
DTC and 1st trip DTC can be read by the following methods.
(
With CONSULT-II or
GST) CONSULT-II or GST (Generic Scan Tool) Examples: P0705, P0710,
P0720, P0725, etc.
These DTCs are prescribed by SAE J2012.
(CONSULT-II also displays the malfunctioning component or system.)
●
1st trip DTC No. is the same as DTC No.
●
Output of the diagnostic trouble code indicates that the indicated circuit has a malfunction. How-
ever, in case of the Mode II and GST they do not indicate whether the malfunction is still occurring
or occurred in the past and returned to normal.
CONSULT-II can identify them as shown below. Therefore, using CONSULT-II (if available) is rec-
ommended.
Items
MIL
One trip detection
Two trip detection
Shift solenoid valve A — DTC: P0750
X
Shift solenoid valve B — DTC: P0755
X
Accelerator pedal position (APP) sensor — DTC: P1705
X
Except above
X
