NISSAN X-TRAIL 2003 Service Repair Manual

DTC P0401 EGR FUNCTION
EC-1073
[YD (WITH EURO-OBD)]
C
D
E
F
G
H
I
J
K
L
MA
EC

DTC P0401 EGR FUNCTIONPFP:14710
DescriptionEBS011OS
SYSTEM DESCRIPTION
*: These signals are sent to the ECM through CAN communication line.
This system controls flow rate of EGR led from exhaust manifold to intake manifold. The opening of the EGR
by-pass passage in the EGR volume control valve changes to control the flow rate. A built-in step motor
moves the valve in steps corresponding to the ECM output pulses. The opening of the valve varies for opti-
mum engine control. The optimum value stored in the ECM is determined by considering various engine con-
ditions.
The EGR volume control valve remains close under the following conditions.

Engine stopped

Engine starting

Low engine coolant temperature

High engine speed

Accelerator pedal fully depressed
COMPONENT DESCRIPTION
EGR Volume Control Valve
The EGR volume control valve uses a step motor to control the flow
rate of EGR from exhaust manifold. This motor has four winding
phases. It operates according to the output pulse signal of the ECM.
Two windings are turned ON and OFF in sequence. Each time an
ON pulse is issued, the valve opens or closes, changing the flow
rate. When no change in the flow rate is needed, the ECM does not
issue the pulse signal. A certain voltage signal is issued so that the
valve remains at that particular opening.
Sensor Input Signal to ECM ECM Function Actuator
Crankshaft position sensor Engine speed
EGR volume con-
trolEGR volume control
valve Vehicle speed sensor* Vehicle speed
Engine coolant temperature sensor Engine coolant temperature
Ignition switch Start signal
Accelerator pedal position sensor Accelerator pedal position
Mass air flow sensor Amount of intake air
Air conditioner switch
* Air conditioner operation
SEF908Y
SEF411Y

EC-1074
[YD (WITH EURO-OBD)]
DTC P0401 EGR FUNCTION

CONSULT-II Reference Value in Data Monitor ModeEBS011OT
Specification data are reference values.
ECM Terminals and Reference ValueEBS011OU
Specification data are reference values and are measured between each terminal and ground.
CAUTION:
Do not use ECM ground terminals when measuring input/output voltage. Doing so may result in dam-
age to the ECM's transistor. Use a ground other than ECM terminals, such as the ground.
On Board Diagnosis LogicEBS011TY
MONITOR ITEM CONDITION SPECIFICATION
EGR VOL CON/V

Engine: After warming up

Air conditioner switch: OFF

Shift lever: Neutral position

No-loadAfter 1 minute at idle More than 10 steps
Revving engine from idle to 3,600
rpm0 step
TERMI-
NAL
NO.WIRE
COLORITEM CONDITIONDATA
(DC Voltage and Pulse Signal)
25
26
27
28GY
W/L
OR/B
GY/BEGR volume control valve[Engine is running]

Warm-up condition

Idle speed0.1 - 14V
(Voltage signals of each ECM ter-
minals differ according to the con-
trol position of EGR volume
control valve.)
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P0401Exhaust gas recirculation flow
insufficient detectedThe exhaust gas recirculation flow is
insufficient.

Harness or connectors
(The EGR volume control valve
circuit is open or shorted.)

EGR volume control valve stuck
closed

EGR passage clogged

DTC P0401 EGR FUNCTION
EC-1075
[YD (WITH EURO-OBD)]
C
D
E
F
G
H
I
J
K
L
MA
EC

DTC Confirmation ProcedureEBS011TZ
NOTE:
If DTC Confirmation Procedure has been previously conducted, always turn ignition switch OFF and wait at
least 10 seconds before conducting the next test.
WITH CONSULT-II
1. Turn ignition switch ON and select “DATA MONITOR” mode with
CONSULT-II.
2. Start engine.
3. Maintain the following conditions for at least 40 consecutive sec-
onds.
4. If 1st trip DTC is detected, go to EC-1077, "
Diagnostic Proce-
dure" .
WITH GST
Follow the procedure “WITH CONSULT-II” above.
PBIB2156E
COOLAN TEMP/S 50 - 89 °C (122 - 192 °F)
Voltage between ECM terminal 55 (Intake air tem-
perature sensor) and ground1.7 - 2.6V
PBIB2017E

EC-1076
[YD (WITH EURO-OBD)]
DTC P0401 EGR FUNCTION

Wiring DiagramEBS011OV
TBWA0579E

DTC P0401 EGR FUNCTION
EC-1077
[YD (WITH EURO-OBD)]
C
D
E
F
G
H
I
J
K
L
MA
EC

Diagnostic ProcedureEBS011OW
1. CHECK EGR VOLUME CONTROL VALVE POWER SUPPLY CIRCUIT-I
1. Turn ignition switch OFF.
2. Disconnect EGR volume control valve harness connector.
3. Turn ignition switch ON.
4. Check voltage between EGR volume control valve terminals 2, 5
and ground with CONSULT-II or tester.
OK or NG
OK >> GO TO 3.
NG >> GO TO 2.
2. DETECT MALFUNCTIONING PART
Check the following.

Harness connectors F30, M63

Harness for open or short between EGR volume control valve and ECM

Harness for open or short between EGR volume control valve and ECM relay
>> Repair open circuit or short to ground or short to power in harness or connectors.
3. CHECK EGR VOLUME CONTROL VALVE OUTPUT SIGNAL CIRCUIT FOR OPEN AND SHORT
1. Turn ignition switch OFF.
2. Disconnect ECM harness connector.
3. Check harness continuity between ECM terminals and EGR volume control valve terminals as follows.
Refer to Wiring Diagram.
4. Also check harness for short to ground and short to power.
OK or NG
OK >> GO TO 4.
NG >> Repair open circuit or short to ground or short to power in harness or connectors.
PBIB1901E
Voltage: Battery voltage
PBIB2013E
ECM terminal EGR volume control valve terminal
25 1
26 6
27 3
28 4
Continuity should exist.

EC-1078
[YD (WITH EURO-OBD)]
DTC P0401 EGR FUNCTION

4. CHECK EGR VOLUME CONTROL VALVE
Refer to EC-1078, "
Component Inspection" .
OK or NG
OK >> GO TO 5.
NG >> Replace EGR volume control valve.
5. CHECK EGR PASSAGE
Check the following for clogging and cracks.

EGR tube

EGR hose

EGR cooler
OK or NG
OK >> GO TO 6.
NG >> Repair or replace EGR passage.
6. CHECK INTERMITTENT INCIDENT
Refer to EC-936, "
TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT" .
>>INSPECTION END
Component InspectionEBS011V3
EGR VOLUME CONTROL VALVE
With CONSULT-II
1. Disconnect EGR volume control valve harness connector.
2. Check resistance between the following terminals.

terminal 2 and terminals 1, 3

terminal 5 and terminals 4, 6
If NG, replace EGR volume control valve.
If OK, go to next step.
3. Remove EGR volume control valve from cylinder head.
4. Reconnect EGR volume control valve harness connector.
5. Turn ignition switch ON.
Temperature °C (°F) Resistance Ω
20 (68) 13 - 17
PBIB2014E

DTC P0401 EGR FUNCTION
EC-1079
[YD (WITH EURO-OBD)]
C
D
E
F
G
H
I
J
K
L
MA
EC

6. Perform “EGR VOL CONT/V” in “ACTIVE TEST” mode with CONSULT-II. Check that EGR volume control
valve shaft moves smoothly forward and backward according to the valve opening.
If NG, replace the EGR volume control valve.
NOTE:
When installing the EGR volume control valve, make sure that the shaft is in the same position before
checking.
Without CONSULT-II
1. Disconnect EGR volume control valve harness connector.
2. Check resistance between the following terminals.

terminal 2 and terminals 1, 3

terminal 5 and terminals 4, 6
If NG, replace EGR volume control valve.
If OK, go to next step.
3. Remove EGR volume control valve from cylinder head.
4. Reconnect EGR volume control valve harness connector.
5. Turn ignition switch ON and OFF.
6. Check that EGR volume control valve shaft moves smoothly for-
ward and backward according to the ignition switch position.
If NG, replace EGR volume control valve.
NOTE:
When installing the EGR volume control valve, make sure that
the shaft is in the same position before checking.
Removal and InstallationEBS011V4
EGR VOLUME CONTROL VALVE
Refer to EM-136, "INTAKE MANIFOLD" .
SEF819Y
Temperature °C (°F) Resistance Ω
20 (68) 13 - 17
PBIB2014E
SEF560W

EC-1080
[YD (WITH EURO-OBD)]
DTC P0404 EGR VOLUME CONTROL VALVE

DTC P0404 EGR VOLUME CONTROL VALVEPFP:14710
DescriptionEBS011P6
SYSTEM DESCRIPTION
*: These signals are sent to the ECM through CAN communication line.
This system controls flow rate of EGR led from exhaust manifold to intake manifold. The opening of the EGR
by-pass passage in the EGR volume control valve changes to control the flow rate. A built-in step motor
moves the valve in steps corresponding to the ECM output pulses. The opening of the valve varies for opti-
mum engine control. The optimum value stored in the ECM is determined by considering various engine con-
ditions.
The EGR volume control valve remains close under the following conditions.

Engine stopped

Engine starting

Low engine coolant temperature

High engine speed

Accelerator pedal fully depressed
COMPONENT DESCRIPTION
EGR Volume Control Valve
The EGR volume control valve uses a step motor to control the flow
rate of EGR from exhaust manifold. This motor has four winding
phases. It operates according to the output pulse signal of the ECM.
Two windings are turned ON and OFF in sequence. Each time an
ON pulse is issued, the valve opens or closes, changing the flow
rate. When no change in the flow rate is needed, the ECM does not
issue the pulse signal. A certain voltage signal is issued so that the
valve remains at that particular opening.
Sensor Input Signal to ECM ECM Function Actuator
Crankshaft position sensor Engine speed
EGR volume con-
trolEGR volume control
valve Vehicle speed sensor* Vehicle speed
Engine coolant temperature sensor Engine coolant temperature
Ignition switch Start signal
Accelerator pedal position sensor Accelerator pedal position
Mass air flow sensor Amount of intake air
Air conditioner switch
* Air conditioner operation
SEF908Y
SEF411Y

DTC P0404 EGR VOLUME CONTROL VALVE
EC-1081
[YD (WITH EURO-OBD)]
C
D
E
F
G
H
I
J
K
L
MA
EC

CONSULT-II Reference Value in Data Monitor ModeEBS011P7
Specification data are reference values.
ECM Terminals and Reference ValueEBS011P8
Specification data are reference values and are measured between each terminal and ground.
CAUTION:
Do not use ECM ground terminals when measuring input/output voltage. Doing so may result in dam-
age to the ECM's transistor. Use a ground other than ECM terminals, such as the ground.
On Board Diagnosis LogicEBS011U2
DTC Confirmation ProcedureEBS011U3
NOTE:
If DTC Confirmation Procedure has been previously conducted, always turn ignition switch OFF and wait at
least 10 seconds before conducting the next test.
WITH CONSULT-II
1. Turn ignition switch ON and select “DATA MONITOR” mode with
CONSULT-II.
2. Start engine.
3. Maintain the following conditions for at least 20 consecutive sec-
onds.
MONITOR ITEM CONDITION SPECIFICATION
EGR VOL CON/V

Engine: After warming up

Air conditioner switch: OFF

Shift lever: Neutral position

No-loadAfter 1 minute at idle More than 10 steps
Revving engine from idle to 3,600
rpm0 step
TERMI-
NAL
NO.WIRE
COLORITEM CONDITIONDATA
(DC Voltage and Pulse Signal)
25
26
27
28GY
W/L
OR/B
GY/BEGR volume control valve[Engine is running]

Warm-up condition

Idle speed0.1 - 14V
(Voltage signals of each ECM ter-
minals differ according to the con-
trol position of EGR volume
control valve.)
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P0404Exhaust gas recirculation con-
trol circuit range/performanceAn improper voltage signal is sent to
ECM through EGR volume control
valve.

Harness or connectors
(The EGR volume control valve
circuit is open or shorted.)

EGR volume control valve stuck
closed
PBIB2156E

EC-1082
[YD (WITH EURO-OBD)]
DTC P0404 EGR VOLUME CONTROL VALVE

4. If 1st trip DTC is detected, go to EC-1084, "Diagnostic Proce-
dure" .
WITH GST
Follow the procedure “WITH CONSULT-II” above.
COOLAN TEMP/S 22 - 87 °C (72 - 189 °F)
Voltage between ECM terminal 55 (Intake air tem-
perature sensor) and ground0.9 - 4.0V
PBIB2017E