2003 NISSAN X-TRAIL ESP

ENGINE CONTROL SYSTEM
EC-41
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EC

M/T MODELS WITH ESP
System Diagram
Input/output Signal Chart
T: Transmit R: Receive
*1: YD engine models only
*2: QR engine models only
PKIA6459E
Signals ECMESP/TCS/ABS
control unitSteering angle
sensor4WD control
unitCombination
meter
Stop lamp switch signal T R
Engine speed signal T R R R
Engine coolant temperature signal TR
Accelerator pedal position signal T R R
A/C switch signal*
1RT
A/C compressor feedback signal*
2TR
Vehicle speed signalTRR
RT
ABS warning lamp signal T R
Brake warning lamp signal T R
SLIP indicator lamp signal T R
ESP OFF indicator lamp signal T R
4WD warning lamp signalTR
4WD mode indicator lamp signalTR
Parking brake switch signalRT
MI signal TR
Glow indicator lamp signal*
1TR
Steering angle sensor signal R T

EC-42
[QR (WITH EURO-OBD)]
ENGINE CONTROL SYSTEM

A/T MODELS WITH ESP
System Diagram
Input/output Signal Chart
T: Transmit R: Receive
PKIA6460E
Signals ECM TCMESP/TCS/
ABS control
unitSte ering
angle sensor4WD control
unitCombination
meter
Stop lamp switch signalRT
TR
P·N range signal R T
A/T position indicator lamp signal T R R
O/D OFF indicator signal T R
Overdrive control switch signal R T
Closed throttle position signal T R
Wide open throttle position signal T R
Engine speed signal T R R R
Engine coolant temperature signal TR
Accelerator pedal position signal T R R
Output shaft revolution signal R T
A/C compressor feedback signal TR
Vehicle speed signalTRR
RT
ABS warning lamp signal T R
Brake warning lamp signal T R
SLIP indicator lamp signal T R
ESP OFF indicator lamp signal T R
4WD warning lamp signalTR
4WD mode indicator lamp signalTR
Parking brake switch signalRT
MI signal TR
Steering angle sensor signal R T

ENGINE CONTROL SYSTEM
EC-43
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EC
Engine and A/T integratedTR
RT
A/T self-diagnosis signal R TSignals ECM TCMESP/TCS/
ABS control
unitSteering
angle sensor4WD control
unitCombination
meter

EC-54
[QR (WITH EURO-OBD)]
ON BOARD DIAGNOSTIC (OBD) SYSTEM

*1: 1st trip DTC No. is the same as DTC No.
*2: This number is prescribed by ISO 15031-5.
*3: In Diagnostic Test Mode II (Self-diagnostic results), this number is controlled by NISSAN.
*4: This is not displayed with GST.
*5: The troubleshooting for this DTC needs CONSULT-II.
*6: For models with ESP system.
DTC AND 1ST TRIP DTC
The 1st trip DTC (whose number is the same as the DTC number) is displayed for the latest self-diagnostic
result obtained. If the ECM memory was cleared previously, and the 1st trip DTC did not reoccur, 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 MI will not
light up (two trip detection logic). If the same malfunction 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 the ECM memory and the MI lights up. In other words,
the DTC is stored in the ECM memory and the MI lights 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. For malfunctions that blink or light up the MI 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 DTC from the ECM memory are described in EC-63, "
HOW
TO ERASE EMISSION-RELATED DIAGNOSTIC INFORMATION" .
For malfunctions in which 1st trip DTCs are displayed, refer to EC-52
. These items are required by legal reg-
ulations to continuously monitor the system/component. In addition, the items monitored non-continuously are
also displayed on CONSULT-II.
1st trip DTC is specified in Mode 7 of ISO 15031-5. 1st trip DTC detection occurs without lighting up the MI
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 II, refer to EC-74
. Then perform DTC Confirmation Procedure
or Overall Function Check to try to duplicate the malfunction. If the malfunction 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-II
With GST
CONSULT-II or GST (Generic Scan Tool) Examples: P0340, P0740, P0745, etc.
This DTC is prescribed by ISO 15031-5.
(CONSULT-II also displays the malfunctioning component or system.)
No Tools
The number of blinks of the MI in the Diagnostic Test Mode II (Self-Diagnostic Results) indicates the DTC.
Example: 0102, 0340 etc.
This DTC is controlled by NISSAN.

1st trip DTC No. is the same as DTC No.

Output of a DTC indicates a malfunction. However, GST or 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-II can identify malfunction status as shown below. Therefore, using CONSULT-II (if
available) is recommended.
APP SEN 1/CIRC P2123 2123 — — —EC-386
APP SEN 2/CIRC P2127 2127 — — —EC-393
APP SEN 2/CIRC P2128 2128 — — —EC-393
TP SENSOR P2135 2135 — — —EC-401
APP SENSOR P2138 2138 — — —EC-409
Items
(CONSULT-II screen terms)DTC*
1
SRT codeTe s t Va l v e /
Test Limit
(GST only)1st trip DTC Reference page
CONSULT-II
GST*
2ECM*3

ON BOARD DIAGNOSTIC (OBD) SYSTEM
EC-57
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EC

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-II.
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.
When all SRT related self-diagnoses showed OK results in a single cycle (Ignition OFF-ON-OFF), the SRT will
indicate “CMPLT”. → Case 1 above
When all SRT related self-diagnoses showed 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 showed NG results in 2 consecutive cycles, the SRT will also indi-
cate “CMPLT”. → Case 3 above
The table above shows that the minimum number of cycles 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
SRT item
(CONSULT-II
indication)Performance
Priority*Required self-diagnostic items to set the SRT to “CMPLT” Corresponding DTC No.
CATALYST 2 Three way catalyst function P0420
HO2S 1 Heated oxygen sensor 1 P0133
Heated oxygen sensor 1 P1143
Heated oxygen sensor 1 P1144
Heated oxygen sensor 2 P0139
Heated oxygen sensor 2 P1146
Heated oxygen sensor 2 P1147
HO2S HTR 1 Heated oxygen sensor 1 heater P0031, P0032
Heated oxygen sensor 2 heater P0037, P0038
Self-diagnosis resultExample
DiagnosisIgnition cycle
← ON → OFF ← ON → OFF ← ON → OFF ← ON →
All OK Case 1 P0400 OK (1) — (1) OK (2) — (2)
P0402 OK (1) — (1) — (1) OK (2)
P1402 OK (1) OK (2) — (2) — (2)
SRT of EGR “CMPLT” “CMPLT” “CMPLT” “CMPLT”
Case 2 P0400 OK (1) — (1) — (1) — (1)
P0402 — (0) — (0) OK (1) — (1)
P1402 OK (1) OK (2) — (2) — (2)
SRT of EGR “INCMP” “INCMP” “CMPLT” “CMPLT”
NG exists Case 3 P0400 OK OK — —
P0402 — — — —
P1402 NG — NGNG
(Consecutive
NG)
(1st trip)
DTC1st trip DTC — 1st trip DTCDTC
(= MI “ON”)
SRT of EGR “INCMP” “INCMP” “INCMP” “CMPLT”

EC-58
[QR (WITH EURO-OBD)]
ON BOARD DIAGNOSTIC (OBD) SYSTEM

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.

When, during SRT driving pattern, 1st trip DTC (NG) is detected prior to “CMPLT” of SRT, the self-diagno-
sis 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.

EC-60
[QR (WITH EURO-OBD)]
ON BOARD DIAGNOSTIC (OBD) SYSTEM

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-II
Perform corresponding DTC Confirmation Procedure one by one based on Performance Priority in the table
on EC-57
.
WITHOUT CONSULT-II
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.

TROUBLE DIAGNOSIS
EC-73
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EC

TROUBLE DIAGNOSISPFP:00004
Trouble Diagnosis IntroductionEBS010LP
INTRODUCTION
The engine has an ECM to control major systems such as fuel con-
trol, ignition control, idle air control system, etc. The ECM accepts
input signals from sensors and instantly drives actuators. It is essen-
tial that both input and output signals are proper and stable. At the
same time, it is important that there are no malfunctions such as vac-
uum leaks, fouled spark plugs, or other malfunctions with the engine.
It is much more difficult to diagnose an incident that occurs intermit-
tently rather than continuously. Most intermittent incidents are
caused by poor electric connections or improper wiring. In this case,
careful checking of suspected circuits may help prevent the replace-
ment of good parts.
A visual check only may not find the cause of the incidents. A road
test with CONSULT-II (or GST) or a circuit tester connected should
be performed. Follow the Work Flow on EC-74
.
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 incidents, especially
intermittent ones. Find out what symptoms are present and under
what conditions they occur. A Diagnostic Worksheet like the example
on EC-76
should be used.
Start your diagnosis by looking for conventional malfunctions first.
This will help troubleshoot driveability malfunctions on an electroni-
cally controlled engine vehicle.
MEF036D
SEF233G
SEF234G