Nissan Pathfinder (2006 year). Manual - part 6

A/T CONTROL SYSTEM

AT-39

2006 Pathfinder

Pressure switch 5 (D/C)

Detects any malfunction in the direct clutch hydraulic pressure. When it detects any mal-
function, it puts the system into fail-safe mode.

Pressure switch 6 (HLR/C)

Detects any malfunction in the high and low reverse clutch hydraulic pressure. When it
detects any malfunction, it puts the system into fail-safe mode.

Name

Function

AT-40

ON BOARD DIAGNOSTIC (OBD) SYSTEM

2006 Pathfinder

ON BOARD DIAGNOSTIC (OBD) SYSTEM

PFP:00028

Introduction

ECS00EEW

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 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 indicator lamp. The malfunction is
stored in the TCM memory. The detected items are overlapped with OBD-II self-diagnostic items. For detail,
refer to

AT-90, "SELF-DIAGNOSTIC RESULT MODE"

OBD-II Function for A/T System

ECS00EEX

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

ECS00EEY

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. — 1st Trip
If the same malfunction as that experienced during the first test drive is sensed during the second test drive,
the MIL will illuminate. — 2nd Trip
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)

ECS00EEZ

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, P0720 etc.

These DTC 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, CONSULT-II (if available) is recom-
mended.

A sample of CONSULT-II display for DTC and 1st trip DTC is shown
on the next page. DTC or 1st trip DTC of a malfunction is displayed
in SELF-DIAGNOSTIC RESULTS mode for “ENGINE” with CON-
SULT-II. Time data indicates how many times the vehicle was driven
after the last detection of a DTC.

BCIA0030E

ON BOARD DIAGNOSTIC (OBD) SYSTEM

AT-41

2006 Pathfinder

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”.

Freeze Frame Data and 1st Trip Freeze Frame Data

The ECM has a memory function, which stores the driving condition such as fuel system status, calculated
load value, engine coolant temperature, short term fuel trim, long term fuel trim, engine speed and vehicle
speed at the moment the ECM detects a malfunction.
Data which are stored in the ECM memory, along with the 1st trip DTC, are called 1st trip freeze frame data,
and the data, stored together with the DTC data, are called freeze frame data and displayed on CONSULT-II
or GST. The 1st trip freeze frame data can only be displayed on the CONSULT-II screen, not on the GST. For
detail, refer to

AT-40, "ON BOARD DIAGNOSTIC (OBD) SYSTEM"

Only one set of freeze frame data (either 1st trip freeze frame data of freeze frame data) can be stored in the
ECM. 1st trip freeze frame data is stored in the ECM memory along with the 1st trip DTC. There is no priority
for 1st trip freeze frame data and it is updated each time a different 1st trip DTC is detected. However, once
freeze frame data (2nd trip detection/MIL on) is stored in the ECM memory, 1st trip freeze frame data is no
longer stored. Remember, only one set of freeze frame data can be stored in the ECM. The ECM has the fol-
lowing priorities to update the data.

Both 1st trip freeze frame data and freeze frame data (along with the DTC) are cleared when the ECM mem-
ory is erased.

HOW TO ERASE DTC

The diagnostic trouble code can be erased by CONSULT-II, GST or ECM DIAGNOSTIC TEST MODE as
described following.

●

If the battery cable is disconnected, the diagnostic trouble code will be lost within 24 hours.

●

When you erase the DTC, using CONSULT-II or GST is easier and quicker than switching the mode
selector on the ECM.

The following emission-related diagnostic information is cleared from the ECM memory when erasing DTC
related to OBD-II. For details, refer to

EC-48, "EMISSION-RELATED DIAGNOSTIC INFORMATION ITEMS"

●

Diagnostic trouble codes (DTC)

●

1st trip diagnostic trouble codes (1st trip DTC)

●

Freeze frame data

SAT015K

SAT016K

Priority

Items

Freeze frame data

Misfire — DTC: P0300 - P0306
Fuel Injection System Function — DTC: P0171, P0172, P0174, P0175

Except the above items (Includes A/T related items)

1st trip freeze frame data

AT-42

ON BOARD DIAGNOSTIC (OBD) SYSTEM

2006 Pathfinder

●

1st trip freeze frame data

●

System readiness test (SRT) codes

●

Test values

HOW TO ERASE DTC (WITH CONSULT-II)

●

If a DTC is displayed for both ECM and TCM, it is necessary to be erased for both ECM and TCM.

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.

Turn CONSULT-II “ON” and touch “A/T”.

Touch “SELF-DIAG RESULTS”.

Touch “ERASE”. (The DTC in the TCM will be erased.) Then touch “BACK” twice.

Touch “ENGINE”.

Touch “SELF-DIAG RESULTS”.

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

HOW TO ERASE DTC (WITH GST)

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 Mode 4 with the Generic Scan Tool (GST). For details refer to

EC-125, "Generic Scan Tool (GST)

Function"

SCIA5671E

ON BOARD DIAGNOSTIC (OBD) SYSTEM

AT-43

2006 Pathfinder

HOW TO ERASE DTC (NO TOOLS)

Disconnect battery for 24 hours.

Reconnect battery.

Malfunction Indicator Lamp (MIL)

ECS00EF0

DESCRIPTION

The MIL is located on the instrument panel.

The MIL will light up when the ignition switch is turned “ON” with-
out the engine running. This is a bulb check.

●

If the MIL does not light up, refer to

DI-33, "WARNING LAMPS"

When the engine is started, the MIL should go off.
If the MIL remains on, the on board diagnostic system has
detected an engine system malfunction.

SEF217U

AT-44

TROUBLE DIAGNOSIS

2006 Pathfinder

TROUBLE DIAGNOSIS

PFP:00004

DTC Inspection Priority Chart

ECS00EF1

If some DTCs are displayed at the same time, perform inspections one by one based on the following priority
chart.

NOTE:
If DTC U1000 is displayed with other DTCs, first perform the trouble diagnosis for DTC U1000. Refer to

AT-103

Fail-Safe

ECS00EF2

The TCM has an electrical fail-safe mode. This mode makes it possible to operate even if there is an error in a
main electronic control input/output signal circuit. In fail-safe mode the transmission is fixed in 2nd, 4th or 5th
(depending on the breakdown position), so the customer should feel “slipping” or “poor acceleration”.
Even when the electronic circuits are normal, under special conditions (for example, when slamming on the
brake with the wheels spinning drastically and stopping the tire rotation), the transmission can go into fail-safe
mode. If this happens, switch “OFF” the ignition switch for 10 seconds, then switch it “ON” again to return to
the normal shift pattern. Therefore, the customer's vehicle has returned to normal, so handle according to the
“diagnostics flow” (Refer to

AT-47, "WORK FLOW"

FAIL-SAFE FUNCTION

If any malfunction occurs in a sensor or solenoid, this function controls the A/T to mark driving possible.

Vehicle Speed Sensor

●

Signals are input from two systems - from vehicle speed sensor A/T (revolution sensor) installed on the
transmission and from combination meter so normal driving is possible even if there is a malfunction in
one of the systems. And if vehicle speed sensor A/T (revolution sensor) has unusual cases, 5th gear is
prohibited.

Accelerator Pedal Position Sensor

●

Throttle Position Sensor

●

If there is a malfunction in one of the systems, the accelerator opening angle is controlled by ECM accord-
ing to a pre-determined accelerator angle to make driving possible. And if there are malfunctions in tow
systems, the accelerator opening angle is controlled by the idle signal sent from the ECM which is based
on input indicating either idle condition or off-idle condition (pre-determined accelerator opening) in order
to make driving possible.

PNP Switch

●

In the unlikely event that a malfunction signal enters the TCM, the position indicator is switched “OFF”, the
starter relay is switched “OFF” (starter starting is disabled), the back-up lamp relay switched “OFF” (back-
up lamp is OFF) and the position is fixed to the “D” range to make driving possible.

Starter Relay

●

The starter relay is switched “OFF”. (Starter starting is disabled.)

Priority

Detected items (DTC)

U1000 CAN communication line

Except above

TROUBLE DIAGNOSIS

AT-45

2006 Pathfinder

A/T Interlock

●

If there is an A/T interlock judgment malfunction, the transmission is fixed in 2nd gear to make driving pos-
sible.

NOTE:
When the vehicle is driven fixed in 2nd gear, a turbine revolution sensor malfunction is displayed,
but this is not a turbine revolution sensor malfunction.

●

When the coupling pattern below is detected, the fail-safe action corresponding to the pattern is per-
formed.

A/T INTERLOCK COUPLING PATTERN TABLE

●

: NG X: OK

A/T 1st Engine Braking

●

When there is an A/T first gear engine brake judgment malfunction, the low coast brake solenoid is
switched “OFF” to avoid the engine brake operation.

Line Pressure Solenoid

●

The solenoid is switched “OFF” and the line pressure is set to the maximum hydraulic pressure to make
driving possible.

Torque Converter Clutch Solenoid

●

The solenoid is switched “OFF” to release the lock-up.

Low Coast Brake Solenoid

●

When a (electrical or functional) malfunction occurs, in order to make driving possible, the engine brake is
not applied in 1st and 2nd gear.

Input Clutch Solenoid

●

If a (electrical or functional) malfunction occurs with the solenoid either “ON” or “OFF”, the transmission is
held in 4th gear to make driving possible.

Direct Clutch Solenoid

●

If a (electrical or functional) malfunction occurs with the solenoid either “ON” or “OFF”, the transmission is
held in 4th gear to make driving possible.

Front Brake Solenoid

●

If a (electrical or functional) malfunction occurs with the solenoid “ON”, in order to make driving possible,
the A/T is held in 5th gear; if the solenoid is OFF, 4th gear.

High and Low Reverse Clutch Solenoid

●

If a (electrical or functional) malfunction occurs with the solenoid either “ON” or “OFF”, the transmission is
held in 4th gear to make driving possible.

Turbine Revolution Sensor 1 or 2

●

The control is the same as if there were no turbine revolution sensors, 5th gear is prohibited.

Gear position

ATF pressure switch output

Fail-safe

function

Clutch pressure output pattern after fail-safe func-

tion

SW3

(I/C)

SW6

(HLR/

SW5

(D/C)

SW1

(FR/B)

SW2

(LC/B)

I/C

HLR/C

D/C

FR/B

LC/B

L/U

A/T inter-
lock cou-
pling pattern

3rd

–

●

Held in

2nd gear

OFF

4th

–

●

Held in

2nd gear

OFF

5th

–

●

Held in

2nd gear

OFF

AT-46

TROUBLE DIAGNOSIS

2006 Pathfinder

How To Perform Trouble Diagnosis For Quick and Accurate Repair

ECS00EF3

INTRODUCTION

The TCM receives a signal from the vehicle speed sensor, accelerator pedal position sensor (throttle position
sensor) or PNP switch and provides shift control or lock-up control via A/T solenoid valves.
The TCM also communicates with the ECM by means of a signal
sent from sensing elements used with the OBD-related parts of the
A/T system for malfunction-diagnostic purposes. The TCM is capa-
ble of diagnosing malfunctioning parts while the ECM can store mal-
functions in its memory.
Input and output signals must always be correct and stable in the
operation of the A/T system. The A/T system must be in good oper-
ating condition and be free of valve seizure, solenoid valve malfunc-
tion, etc.

It is much more difficult to diagnose a error that occurs intermittently
rather than continuously. Most intermittent errors are caused by poor
electric connections or improper wiring. In this case, careful check-
ing of suspected circuits may help prevent the replacement of good
parts.
A visual check only may not find the cause of the errors. A road test
with CONSULT-II (or GST) or a circuit tester connected should be
performed. Follow the

AT-47, "WORK FLOW"

Before undertaking actual checks, take a few minutes to talk with a
customer who approaches with a driveability complaint. The cus-
tomer can supply good information about such errors, especially
intermittent ones. Find out what symptoms are present and under
what conditions they occur. A “Diagnostic Worksheet” as shown on
the example (Refer to

AT-48

) should be used.

Start your diagnosis by looking for “conventional” errors first. This will
help troubleshoot driveability errors on an electronically controlled
engine vehicle.
Also check related Service bulletins.

SAT631IB

SAT632I

SEF234G

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