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Nissan Frontier D22. Manual - part 296

DTC P0402 EGRC-BPT VALVE FUNCTION

EC-287

[KA24DE]

DTC P0402 EGRC-BPT VALVE FUNCTION

PFP:14741

Description

UBS00D6Q

SYSTEM DESCRIPTION

The EGRC-BPT valve monitors exhaust pressure to activate the diaphragm, controlling throttle body vacuum
applied to the EGR valve. In other words, recirculated exhaust gas is controlled in response to positioning of
the EGR valve or to engine operation.

On Board Diagnosis Logic

UBS00D6R

If too much EGR flow exists due to an EGRC-BPT valve malfunction, off idle engine roughness will increase. If
the roughness is large, then the vacuum to the EGR valve is interrupted through the EGRC solenoid valve. If
the engine roughness is reduced at that time, the EGRC-BPT valve malfunction is indicated.

SEF453PD

DTC No.

Trouble Diagnosis Name

DTC Detecting Condition

Possible Cause

P0402

EGRC-BPT valve function

●

The EGRC-BPT valve does not
operate properly.

●

EGRC-BPT valve

●

EGR valve

●

Loose or disconnected rubber tube

●

Blocked rubber tube

●

Camshaft position sensor

●

Blocked exhaust system

●

Orifice

●

Mass air flow sensor

●

EGRC solenoid valve

EC-288

[KA24DE]

DTC P0402 EGRC-BPT VALVE FUNCTION

DTC Confirmation Procedure

UBS00D6S

CAUTION:

Always drive vehicle at a safe speed.

NOTE:
If “DTC Confirmation Procedure” has been previously conducted, always turn ignition switch OFF and wait at
least 5 seconds before conducting the next test.
TESTING CONDITION:
Before performing the following procedure, confirm that battery voltage is more than 11V at idle.

WITH CONSULT-II

Install vacuum gauge between EGRC-BPT valve and EGR
valve as shown in the illustration.

Start engine and warm it up to normal operating temperature.

Stop engine and wait at least 5 seconds.

Turn ignition switch ON and select “EGRC-BPT VLV P0402” of
“EGR SYSTEM” in “DTC WORK SUPPORT” mode with CON-
SULT-II.

Start engine and let it idle.

Touch “START”.

Check the output voltage of “THRTL POS SEN” (at closed throt-
tle position) and note it.

When the following conditions are met, “TESTING” will be dis-
played on the CONSULT-II screen and the bar chart may
increase. Maintain the conditions many times until “COM-
PLETED” appears.

SEF930VA

SEF718Z

Selector lever

Suitable position

ENG SPEED

1,400 - 2,000 rpm (M/T)
1,400 - 1,800 rpm (A/T)

Vehicle speed

30 - 100 km/h (19 - 62 MPH) (M/T)
30 - 55 km/h (19 - 34 MPH) (A/T)

B/FUEL SCHDL

5 - 7.5 msec (M/T)
5.5 - 8.0 msec (A/T)

THRTL POS SEN

(X – (X + 0.88) V
X = Voltage value measured at step 7

SEF719Z

DTC P0402 EGRC-BPT VALVE FUNCTION

EC-289

[KA24DE]

NOTE:

●

The bar chart on CONSULT-II screen indicates the status
of this test. However, the test may be finished before the
bar chart becomes full scale.

●

If the bar chart indication does not continue to progress,
completely release accelerator pedal once and try to
meet the conditions again.

●

If “TESTING” does not appear on CONSULT-II screen,
retry from step 2.

If CONSULT-II instructs to carry out “Overall Function Check”,
go to next step. If “NG” is displayed, refer to

EC-290, "Diagnostic

Procedure"

10. Open engine hood.
11. Raise engine speed to 2,400 to 3,200 rpm under no-load and

hold it. Then touch “NEXT” on CONSULT-II screen.

12. Check vacuum gauge while keeping engine speed at 2,400 to

3,200 rpm.
Vacuum should be 0 to

−20 kPa (0 to −150 mmHg, 0 to −5.91

inHg).
If NG, go to

EC-290, "Diagnostic Procedure"

If OK, touch “YES” on the CONSULT-II screen.

13. Check the EGR valve lifting when revving from 2,000 rpm to

4,000 rpm quickly under no load.
EGR valve should lift up, and go down without sticking when the
engine is returned to idle.
If NG, check EGR valve.
If OK, touch “YES” or the CONSULT-II screen.

14. Check the rubber tube between intake manifold collector, EGRC solenoid valve, EGR valve and EGRC-

BPT valve for cracks, blockages or twisting.
If NG, repair or replace.
If OK, touch “YES” on the CONSULT-II screen.

Overall Function Check

UBS00D6T

Use this procedure to check the overall function of the EGRC-BPT valve. During this check, a 1st trip DTC
might not be confirmed.

WITH GST

Install vacuum gauge between EGRC-BPT valve and EGR
valve as shown in the illustration.

Lift up vehicle.

Start engine and shift to 1st gear position.

Check vacuum gauge while keeping engine speed at 2,400 to
3,200 rpm.
Vacuum should be 0 to

−20 kPa (0 to −150 mmHg, 0 to −5.91

inHg).
If NG, go to

EC-290, "Diagnostic Procedure"

If OK, go to next step.

LEC038A

SEF384X

PEF963V

SEF930V

EC-290

[KA24DE]

DTC P0402 EGRC-BPT VALVE FUNCTION

Check the EGR valve lifting when revving from 2,000 rpm to 4,000 rpm quickly under no load.
EGR valve should lift up, and go down without sticking when the engine is returned to idle.

Check rubber tube between intake manifold collector, EGRC solenoid valve, EGR valve and EGRC-BPT
valve for misconnection, cracks or blockages.

If NG, go to

EC-290, "Diagnostic Procedure"

Diagnostic Procedure

UBS00D6U

CHECK HOSE

Check vacuum hose for clogging and improper connection.

OK or NG

>> GO TO 2.

>> Repair or replace vacuum hose.

CHECK EXHAUST SYSTEM

Check exhaust system for collapse.

OK or NG

>> GO TO 3.

>> Repair or replace exhaust system.

CHECK ORIFICE

Check if orifice is installed in vacuum hose between EGRC-BPT valve and EGRC solenoid valve.
OK or NG

>> GO TO 4.

>> Replace vacuum hose.

CHECK EGRC-BPT VALVE

Refer to

EC-291, "Component Inspection"

OK or NG

>> GO TO 5.

>> Replace EGRC-BPT valve.

CHECK CAMSHAFT POSITION SENSOR

Refer to

EC-291, "Component Inspection"

OK or NG

>> GO TO 6.

>> Replace camshaft position sensor.

CHECK MASS AIR FLOW SENSOR

Refer to

EC-291, "Component Inspection"

OK or NG

>> GO TO 7.

>> Replace mass air flow sensor.

CHECK EGRC SOLENOID VALVE

Refer to

EC-291, "Component Inspection"

OK or NG

>> GO TO 8.

>> Replace EGRC solenoid valve.

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